Accurate identification of natural gas origin is fundamental to the theoretical research on natural gas geosciences and the exploration deployment and resource potential assessment of oil and gas.Since the 1970s,Acade...Accurate identification of natural gas origin is fundamental to the theoretical research on natural gas geosciences and the exploration deployment and resource potential assessment of oil and gas.Since the 1970s,Academician Dai Jinxing has developed a comprehensive system for natural gas origin determination,grounded in geochemical theory and practice,and based on the integrated analysis of stable isotopic compositions,molecular composition,light hydrocarbon fingerprints,and geological context.This paper systematically reviews the core framework established by him and his team according to related references and application results,focusing on the conceptual design and technical pathways of key diagnostic diagrams such asδ^(13)C_(1)-C_(1)/(C_(2)+C_(3)),δ^(13)C_(1)-δ^(13)C_(2)-δ^(13)C_(3),δ^(13)CCO_(2)versus CO_(2)content,and the C7light hydrocarbon ternary plot.We evaluate the applicability and innovation of these tools in distinguishing between oil-type gas,coal-derived gas,microbial gas,and abiogenic gas,as well as in identifying mixed-source gases and multi-stage charging systems.The findings suggest that this identification system has significantly advanced natural gas geochemical interpretation in China,shifting from single-indicator analyses to multi-parameter integration and from qualitative assessments to systematic graphical identification,and has also exerted considerable influence on international research in natural gas geochemistry.The structured overview of the development trajectory of natural gas origin discrimination methodologies provides a technical support for natural gas geological theory and practice and offers a scientific foundation for the academic evaluation and application of related achievements.展开更多
The (extremely efficient) standard model of the elementary particles and fields makes several assumptions, which call for explanations. Any theory offering next step beyond the standard model must explain at least the...The (extremely efficient) standard model of the elementary particles and fields makes several assumptions, which call for explanations. Any theory offering next step beyond the standard model must explain at least the existence and properties of families and their members and correspondingly the existence of the scalar Higgs and the Yukawa couplings, which in this model take care of masses of fermions and weak bosons and influence the decaying properties of families. The spin-charge-family theory [1-11] is offering a possible explanation for the assumptions of the standard model—for the appearance of families and their members (for the charges of a family members), for the gauge fields, for the scalar fields—interpreting the standard model as its low energy effective manifestation. The spin-charge-family theory predicts at the low energy regime two decoupled groups of four families of quarks and leptons. The predicted fourth family waits to be observed, while the stable fifth family is the candidate to form the dark matter. In this paper properties of families are analysed. The appearance of several scalar fields, all in the bosonic (adjoint) representations with respect to the family groups, while they are doublets with respect to the weak charge, is presented, their properties discussed, it is explained how these scalar fields can effectively be interpreted as the standard model Higgs and the Yukawa couplings. The spin-charge-family theory predicts that there are no supersymmetric partners of the observed fermions and bosons.展开更多
If the singularity of the cosmic Big Bang is taken as the origin of the reference coordinate system,the surrounding vacuum in the initial moments of it would exhibit radially-outward right-handed spiral motion at ligh...If the singularity of the cosmic Big Bang is taken as the origin of the reference coordinate system,the surrounding vacuum in the initial moments of it would exhibit radially-outward right-handed spiral motion at light speed.Based on this spatial motion hypothesis,we derive a unified field equation and a set of Maxwell’s equations for vacuum SWs(Scalar Waves)generating a huge spiral force field that drives the energy to spiral inwardly and distort,leading to the formation of mass.Furthermore,they also uncover that mass is fundamentally an ultimate expression of energy,manifesting as the result of spiral motion of space at light speed.And then,we indirectly validate the theory that coherent light waves’collision generate SWs and subsequently mass through the experiment verifying the Breit-Wheeler process.The establishment of our theory offers a new analytical tool for the exploration of mass origin,the cosmic Big Bang,unified field theories.展开更多
Hydrocarbons are one of the important fluids within the Earth's crust,and different biotic and abitoic processes can generate hydrocarbon during geological periods.Tracing the sources and sinks of hydrocarbons can...Hydrocarbons are one of the important fluids within the Earth's crust,and different biotic and abitoic processes can generate hydrocarbon during geological periods.Tracing the sources and sinks of hydrocarbons can help us better understand the carbon cycle of the earth.In this study,an improved approach of adsorbed hydrocarbons extraction from sediments was established.The improved thermal desorption approach,compound-specific isotope analysis and position-specific isotope analysis were integrated to investigate the molecular and intramolecular isotope fractionation between trace hydrocarbon gases within sediments and geological hydrocarbon deposits.The isotopic compositions of the terminal position carbon of propane(δ^(13)C_(terminal))serves as a correlation indicator between trace hydrocarbon gases within sediments and geological hydrocarbon deposits.The tight sandstone gas from the Turpan-Hami Basin is a first case study for the application of this novel method to trace hydrocarbon origins.The results showed that the hydrocarbons in the tight sandstone gases in the study area most likely originated from humic organic matter(typeⅢkerogen)at an early mature stage.δ^(13)C_(terminal)values of the thermally desorbed propane gases from different source rocks were distinguishable and the values of the tight sandstone gases significantly overlap with those of the Lower Jurassic Sangonghe source rocks,suggesting their genetic relationship.Overall,the results provided novel position-specific carbon isotopic constraints on origins of hydrocarbons.展开更多
Spider mites are significant pests in agricultural production.The increasing resistance of spider mites,along with environmental pollution and ecological imbalance caused by their control,is primarily attributed to th...Spider mites are significant pests in agricultural production.The increasing resistance of spider mites,along with environmental pollution and ecological imbalance caused by their control,is primarily attributed to the long-term use of chemical acaricides in agriculture.In contrast,bioactive substances of biological origin offer advantages such as wide availability,environmental friendliness,and low tendency to induce resistance,making them a research hotspot for spider mite control.This review summarizes recent advances in the use of plant-derived active compounds(exemplified by extracts from Veratrum rhizomes),RNA interference(RNAi)technology,and microorganism-derived active substances for controlling spider mites.These bioactive agents exert acaricidal effects by disrupting the nervous system,interfering with metabolic processes,or silencing key genes in mites,demonstrating favorable efficacy and considerable potential for development.However,challenges remain,including poor environmental stability,slow action,high production costs,and insufficient understanding of their effects on non-target organisms.Therefore,future research should focus on the screening and development of novel bioactive substances of biological origin,elucidation of their mechanisms of action,optimization of formulation technologies,and assessment of their ecological safety.These efforts will provide valuable insights for promoting the advancement of bioactive substances and supporting sustainable agricultural development.展开更多
To accurately predict the fatigue properties of additively manufactured(AM)titanium alloys,it is important to understand the fatigue damage origin behavior.However,this behavior is still ambiguous.Therefore,the effect...To accurately predict the fatigue properties of additively manufactured(AM)titanium alloys,it is important to understand the fatigue damage origin behavior.However,this behavior is still ambiguous.Therefore,the effects of internal defects and microstructures on the fatigue damage origin behavior of laser direct energy deposited TC11(LDED-TC11)alloy were investigated using a fatigue origin criterion.The criterion was proposed to analyze the competing and combining effects by coupling the plasticity-corrected crack driving force,the resistance of short cracks,and the modified Kitagawa-Takahashi diagram.Three scenarios corresponding to the criterion were clarified,representing the damage mechanisms dominated by the microstructure,the combined effect of internal defect and microstructure,and the internal defect.As a result,the fatigue fracture morphology of high-cycle fatigue tests demonstrates two fatigue origin modes,i.e.microstructure and gas pore origin modes.The two fatigue modes belong to Scenario I and Scenario II,respectively,which indicates that the fatigue damage origin process of this alloy is sensitive to microstructure.Besides,it was found that the width of the primary a phase of this alloy is strongly relevant to intrinsic defect size.Finally,the fatigue origin criterion was verified in three aspects.展开更多
BACKGROUND Nosocomial fever of unknown origin(nFUO)is a frequent and challenging diagnostic entity,encompassing diverse infectious and non-infectious etiologies.Timely identification is crucial,yet evidence on the dia...BACKGROUND Nosocomial fever of unknown origin(nFUO)is a frequent and challenging diagnostic entity,encompassing diverse infectious and non-infectious etiologies.Timely identification is crucial,yet evidence on the diagnostic accuracy of commonly employed sepsis screening tools and biomarkers remains sparse.We hypothesized that these tools and biomarkers measured at fever onset could distinguish infectious from non-infectious causes of nFUO in critically ill adults.AIM To evaluate the diagnostic utility of sepsis tools and biomarkers in identifying infectious causes of nFUO.METHODS This prospective observational study included patients admitted to the Acute Care Emergency Medicine Unit,Postgraduate Institute of Medical Education and Research,Chandigarh,India(July 2023 to December 2024).nFUO was defined by Durack and Street criteria.Diagnostic performance of sepsis screening tools(systemic inflammatory response syndrome,Sequential Organ Failure Assessment,quick Sequential Organ Failure Assessment,National Early Warning Score,and Modified Early Warning Score)and biomarkers[procalcitonin(PCT),C-reactive protein(CRP)]at fever onset was assessed using receiver operating characteristic curve analysis.RESULTS Of 80 cases(mean age 42.9±16.5 years;80% male),42.5% had infectious causes,38.7% non-infectious,and 18.8% remained undiagnosed.Pneumonia(26.2%)and bloodstream infections(11.2%)were the most common infectious etiologies,while central fever and thrombophlebitis(each 7.5%)were predominant among non-infectious causes.Sepsis tools showed poor diagnostic accuracy,with area under the receiver operating characteristic curve(AUC)values close to 0.5.PCT demonstrated modest performance(AUC=0.61;optimal cut-off:0.85μg/L),while CRP was paradoxically higher in non-infectious cases(AUC=0.45).Overall mortality was 20% and was highest among undiagnosed patients(33.3%).Fever duration and hospitalization length were significantly greater in infectious cases.CONCLUSION Sepsis tools,PCT,and CRP have limited utility in identifying infectious causes of nFUO in critically ill adults and should not solely guide initial decision-making.展开更多
There is no consensus on the tectonic evolution of the western Jiangnan Orogen(WJO)during 770-750 Ma.Thus,we reported zircon trace elements and U‐Pb‐Hf‐O isotopes and whole-rock geochemistry of the Neoproterozoic t...There is no consensus on the tectonic evolution of the western Jiangnan Orogen(WJO)during 770-750 Ma.Thus,we reported zircon trace elements and U‐Pb‐Hf‐O isotopes and whole-rock geochemistry of the Neoproterozoic tuff located in Longsheng,northern Guangxi,in the WJO,to decipher their origin and tectonic setting.The SIMS U‐Pb zircon age yields a concordia age of 772.1±3.8 Ma,suggesting that the tuff layer formed at 770 Ma.Geochemical data of the tuff and its zircon exhibit continental arc signatures.Oxygen isotopes of the zircon show normal mantle zirconδ^(18)O zircon values of 4.59‰-5.50‰with an average of 5.24‰.The zircon yielded positive ε_(Hf)(t)values of 1.8-5.8 with two-stage model ages of 1.32-1.55 Ga.Based on these data and previous studies,the magma source for the tuff is inferred to have originated from the partial melting of the Mesoproterozoic juvenile crust,as the pre-existing arc materials and mixing with the mantle source under the extensional setting during 770-750 Ma triggered by the slab break-off.We infer that the presence of contemporaneous OIB-type and arc-like magmatism at ca.770-750 Ma along the WJO was related to the slab break-off.展开更多
BACKGROUND Fever of unknown origin(FUO)remains a diagnostic challenge and was originally defined in 1961.Its classic criteria include fever≥38.3°C(≥101°F)on multiple occasions,fever lasting three weeks or ...BACKGROUND Fever of unknown origin(FUO)remains a diagnostic challenge and was originally defined in 1961.Its classic criteria include fever≥38.3°C(≥101°F)on multiple occasions,fever lasting three weeks or longer,and a diagnosis after one week of inpatient evaluation.However,these criteria may not fully encompass the varied clinical presentations seen in resource-limited settings such as India.The adaptation of FUO definitions to local healthcare contexts is crucial for enhancing diagnostic accuracy and optimizing patient outcomes.AIM To investigate the applicability of revised FUO criteria in a tertiary care setting in India.METHODS This longitudinal-exploratory study at All India Institute of Medical Sciences Rishikesh(January 2018–December 2022)analyzed 228 adult patients with fever≥99.1°F lasting over three days.Patients diagnosed within three days of admission were excluded.Data were collected retrospectively and prospectively using predefined FUO definitions based on durations of nondiagnosis(3-21 days,>21 days),temperature ranges(99.1°F-100.9°F,≥101°F),and hospitalization durations(3-7 days,>7 days).Descriptive statistics and comparative tests(Fisher's exact test,χ2 test)evaluated outcomes across definitions.RESULTS Among the proposed FUO definitions,Definition B(fever lasting 3-21 days,temperatures between 99.1°F-100.9°F,hospitalization>7 days)predominated(40.8%),while only 2.2%met the classical criteria.Notably,36.5%of Definition B patients remained undiagnosed after 7-10 days,despite 94%undergoing diagnostic workups within 21 days.Infection emerged as the leading etiology across definitions,without significant variation in outcomes or mortality during hospitalization(χ2=27.937,P=0.142).CONCLUSION Adapting FUO criteria to local contexts improves diagnostic accuracy and treatment.Definition B(40.8%prevalence)showed practical utility,with higher mortality in patients discharged on empirical'Anti-tuberculosis therapy'.展开更多
The origin of dolostone in the Middle Jurassic Buqu Formation of the Plateau Basin has been a subject of prolonged debate.This study combines detailed petrological observations with analyses of Mg-C-O isotopes and ele...The origin of dolostone in the Middle Jurassic Buqu Formation of the Plateau Basin has been a subject of prolonged debate.This study combines detailed petrological observations with analyses of Mg-C-O isotopes and elements to constrain the origin of dolostones in the Buqu Formation.Petrography and cathodoluminescence(CL)examination identified three types of matrix dolostones:very finely to finely crystalline dolostone(D1),finely to medium crystalline dolostone(D2),and medium to coarsely crystalline dolostone(D3).The analysis of the diagenesis sequence reveals that D1 originated from the dolomitization of grainstone in the early diagenetic phase,whereas D2 and D3 resulted from the recrystallization of D1 during the later burial phase.The presence of high Na(>100 ppm),low Fe(<1000 ppm),low Mn(<250 ppm),positive Ce anomaly,LREE enrichment,stableδ^(26)Mg(-2.28‰to-2.04‰),andδ^(13)C(1.02‰-2.95‰)indicates that the early dolomitization fluid was oxidized seawater.As the crystal size increases(D1→D2→D3),the progressively rising Mn content and significantly negativeδ^(18)O(-10.72‰to-7.81‰)suggest that the dolostone has experienced modification and alteration by buried pore water in the later stages.The fluctuations in relative sea level during the sedimentary deposition of the Buqu Formation were reconstructed through the utilization of Na,Sr/Cu,Sr/Ba,Rb/Sr,∑REE,andδ^(13)C.It was observed that theδ^(26)Mg of dolostone closely mirrored the variations in sea level.The consistent trend of change confirms that sea level fluctuations control the formation and distribution of early dolostone.Frequent sea level rise and fall prompted the limestone deposited on the carbonate platform to be continuously transformed into dolostone,which accumulates over a long period to form large-scale thick dolostone.After the formation entered the burial stage,under the combined action of high Mg/Ca ratio pore water,high temperature,and high pressure,the early dolostone experienced the adjustment of burial dolomitization.This research offers a typical case study on the application of Mg-C-O isotope and elements to determine the origin of dolostone.This will aid in a more comprehensive understanding of the formation process of dolostone in ancient rock records.展开更多
The origin of engraving and printing has a variety of points of view,especially the“early Tang Dynasty”has the most far-reaching impact.Based on media evolution theory,engraved printing as a new media technology is ...The origin of engraving and printing has a variety of points of view,especially the“early Tang Dynasty”has the most far-reaching impact.Based on media evolution theory,engraved printing as a new media technology is first used in secular culture,folk entertainment,and other fields,after a long period of development,the new medium was accepted by the ruling class,the mainstream society;the use of the media began to intervene in the real society.This reflects that the choice of new media by the society depends on the media itself and is intrinsically linked to the whole social communication environment.Therefore,from the point of view of media evolution,the view that engraving originated in the early Tang Dynasty is not in line with the logic of media evolution and is unreasonable.展开更多
This paper discusses the characteristics and formation mechanism of thin dolomite reservoirs in the lower submember of the second member of the Permian Maokou Formation(lower Mao 2 Member)in the Wusheng-Tongnan area o...This paper discusses the characteristics and formation mechanism of thin dolomite reservoirs in the lower submember of the second member of the Permian Maokou Formation(lower Mao 2 Member)in the Wusheng-Tongnan area of the Sichuan Basin,SW China,through comprehensive analysis of geological,geophysical and geochemical data.The reservoir rocks of the lower Mao 2 Member are dominated by porphyritic vuggy dolomite and calcareous dolomite or dolomitic limestone,which have typical karst characteristics of early diagenetic stage.The dolomites at the edge of the karst system and in the fillings have dissolved estuaries,and the dolomite breccia has micrite envelope and rim cement at the edge,indicating that dolomitization is earlier than the early diagenetic karstification.The shoal facies laminated dolomite is primarily formed by the seepage reflux dolomitization of moderate-salinity seawater.The key factors of reservoir formation are the bioclastic shoal deposition superimposed with seepgae reflux dolomitization and the karstification of early diagenetic stage,which are locally reformed by fractures and hydrothermal processes.The development of dolomite vuggy reservoir is closely related to the upward-shallowing sequence,and mainly occurs in the late highstand of the fourth-order cycle.Moreover,the size of dolomite is closely related to formation thickness,and it is concentrated in the formation thickness conversion area,followed by the thinner area.According to the understanding of insufficient accommodation space in the geomorphic highland and the migration of granular shoal to geomorphic lowland in the late highstand of the third-order cycle,it is proposed that the large-scale shoal-controlled dolomite reservoirs are distributed along structural highs and slopes,and the reservoir-forming model with shoal,dolomitization and karstification jointly controlled by the microgeomorphy and sea-level fluctuation in the sedimentary period is established.On this basis,the paleogeomorphology in the lower Mao 2 Member is restored using well-seismic data,and the reservoir distribution is predicted.The prediction results have been verified by the latest results of exploration wells and tests,which provide an important reference for the prediction of thin dolomite reservoirs under similar geological setting.展开更多
Disseminated mucormycosis is a life-threatening fungal infection with high mortality,particularly in immunocompromised patients.Early diagnosis and prompt intervention are crutial but often delayed due to nonspecific ...Disseminated mucormycosis is a life-threatening fungal infection with high mortality,particularly in immunocompromised patients.Early diagnosis and prompt intervention are crutial but often delayed due to nonspecific presentations.Many studies have highlighted the challenges in emergency settings,where atypical symptoms may lead to misdiagnosis.We report a rare case of disseminated mucormycosis originating from the stomach in a pregnancy-induced thrombocytopenia(PITP)patient,emphasizing rapid gastroscopy examination,histopathological confi rmation,multidisciplinary management,and high-risk factors for hospital-acquired gastrointestinal mucormycosis infection.展开更多
基金Supported by the“14th Five-Year Plan”Prospective and Basic Research Project of CNP)(2021DJ0502)Open Project of Key Laboratory of Shale Gas Resource Exploration(Chongqing Institute of Geology and Mineral Resources),Ministry of Natural Resources(KLSGE-2023)National Natural Science Foundation of China(42172149,U2244209)。
文摘Accurate identification of natural gas origin is fundamental to the theoretical research on natural gas geosciences and the exploration deployment and resource potential assessment of oil and gas.Since the 1970s,Academician Dai Jinxing has developed a comprehensive system for natural gas origin determination,grounded in geochemical theory and practice,and based on the integrated analysis of stable isotopic compositions,molecular composition,light hydrocarbon fingerprints,and geological context.This paper systematically reviews the core framework established by him and his team according to related references and application results,focusing on the conceptual design and technical pathways of key diagnostic diagrams such asδ^(13)C_(1)-C_(1)/(C_(2)+C_(3)),δ^(13)C_(1)-δ^(13)C_(2)-δ^(13)C_(3),δ^(13)CCO_(2)versus CO_(2)content,and the C7light hydrocarbon ternary plot.We evaluate the applicability and innovation of these tools in distinguishing between oil-type gas,coal-derived gas,microbial gas,and abiogenic gas,as well as in identifying mixed-source gases and multi-stage charging systems.The findings suggest that this identification system has significantly advanced natural gas geochemical interpretation in China,shifting from single-indicator analyses to multi-parameter integration and from qualitative assessments to systematic graphical identification,and has also exerted considerable influence on international research in natural gas geochemistry.The structured overview of the development trajectory of natural gas origin discrimination methodologies provides a technical support for natural gas geological theory and practice and offers a scientific foundation for the academic evaluation and application of related achievements.
文摘The (extremely efficient) standard model of the elementary particles and fields makes several assumptions, which call for explanations. Any theory offering next step beyond the standard model must explain at least the existence and properties of families and their members and correspondingly the existence of the scalar Higgs and the Yukawa couplings, which in this model take care of masses of fermions and weak bosons and influence the decaying properties of families. The spin-charge-family theory [1-11] is offering a possible explanation for the assumptions of the standard model—for the appearance of families and their members (for the charges of a family members), for the gauge fields, for the scalar fields—interpreting the standard model as its low energy effective manifestation. The spin-charge-family theory predicts at the low energy regime two decoupled groups of four families of quarks and leptons. The predicted fourth family waits to be observed, while the stable fifth family is the candidate to form the dark matter. In this paper properties of families are analysed. The appearance of several scalar fields, all in the bosonic (adjoint) representations with respect to the family groups, while they are doublets with respect to the weak charge, is presented, their properties discussed, it is explained how these scalar fields can effectively be interpreted as the standard model Higgs and the Yukawa couplings. The spin-charge-family theory predicts that there are no supersymmetric partners of the observed fermions and bosons.
文摘If the singularity of the cosmic Big Bang is taken as the origin of the reference coordinate system,the surrounding vacuum in the initial moments of it would exhibit radially-outward right-handed spiral motion at light speed.Based on this spatial motion hypothesis,we derive a unified field equation and a set of Maxwell’s equations for vacuum SWs(Scalar Waves)generating a huge spiral force field that drives the energy to spiral inwardly and distort,leading to the formation of mass.Furthermore,they also uncover that mass is fundamentally an ultimate expression of energy,manifesting as the result of spiral motion of space at light speed.And then,we indirectly validate the theory that coherent light waves’collision generate SWs and subsequently mass through the experiment verifying the Breit-Wheeler process.The establishment of our theory offers a new analytical tool for the exploration of mass origin,the cosmic Big Bang,unified field theories.
基金financially supported by the National Natural Science Foundation of China(Grant No.42102202)U.S.Department of Energy Geosciences program(DE-SC0016271)。
文摘Hydrocarbons are one of the important fluids within the Earth's crust,and different biotic and abitoic processes can generate hydrocarbon during geological periods.Tracing the sources and sinks of hydrocarbons can help us better understand the carbon cycle of the earth.In this study,an improved approach of adsorbed hydrocarbons extraction from sediments was established.The improved thermal desorption approach,compound-specific isotope analysis and position-specific isotope analysis were integrated to investigate the molecular and intramolecular isotope fractionation between trace hydrocarbon gases within sediments and geological hydrocarbon deposits.The isotopic compositions of the terminal position carbon of propane(δ^(13)C_(terminal))serves as a correlation indicator between trace hydrocarbon gases within sediments and geological hydrocarbon deposits.The tight sandstone gas from the Turpan-Hami Basin is a first case study for the application of this novel method to trace hydrocarbon origins.The results showed that the hydrocarbons in the tight sandstone gases in the study area most likely originated from humic organic matter(typeⅢkerogen)at an early mature stage.δ^(13)C_(terminal)values of the thermally desorbed propane gases from different source rocks were distinguishable and the values of the tight sandstone gases significantly overlap with those of the Lower Jurassic Sangonghe source rocks,suggesting their genetic relationship.Overall,the results provided novel position-specific carbon isotopic constraints on origins of hydrocarbons.
文摘Spider mites are significant pests in agricultural production.The increasing resistance of spider mites,along with environmental pollution and ecological imbalance caused by their control,is primarily attributed to the long-term use of chemical acaricides in agriculture.In contrast,bioactive substances of biological origin offer advantages such as wide availability,environmental friendliness,and low tendency to induce resistance,making them a research hotspot for spider mite control.This review summarizes recent advances in the use of plant-derived active compounds(exemplified by extracts from Veratrum rhizomes),RNA interference(RNAi)technology,and microorganism-derived active substances for controlling spider mites.These bioactive agents exert acaricidal effects by disrupting the nervous system,interfering with metabolic processes,or silencing key genes in mites,demonstrating favorable efficacy and considerable potential for development.However,challenges remain,including poor environmental stability,slow action,high production costs,and insufficient understanding of their effects on non-target organisms.Therefore,future research should focus on the screening and development of novel bioactive substances of biological origin,elucidation of their mechanisms of action,optimization of formulation technologies,and assessment of their ecological safety.These efforts will provide valuable insights for promoting the advancement of bioactive substances and supporting sustainable agricultural development.
基金supported by the National Natural Science Foundation of China(Nos.5175018,52090044)the 2025 Science and Technology Innovation Program of Ningbo,China(No.2022Z014)。
文摘To accurately predict the fatigue properties of additively manufactured(AM)titanium alloys,it is important to understand the fatigue damage origin behavior.However,this behavior is still ambiguous.Therefore,the effects of internal defects and microstructures on the fatigue damage origin behavior of laser direct energy deposited TC11(LDED-TC11)alloy were investigated using a fatigue origin criterion.The criterion was proposed to analyze the competing and combining effects by coupling the plasticity-corrected crack driving force,the resistance of short cracks,and the modified Kitagawa-Takahashi diagram.Three scenarios corresponding to the criterion were clarified,representing the damage mechanisms dominated by the microstructure,the combined effect of internal defect and microstructure,and the internal defect.As a result,the fatigue fracture morphology of high-cycle fatigue tests demonstrates two fatigue origin modes,i.e.microstructure and gas pore origin modes.The two fatigue modes belong to Scenario I and Scenario II,respectively,which indicates that the fatigue damage origin process of this alloy is sensitive to microstructure.Besides,it was found that the width of the primary a phase of this alloy is strongly relevant to intrinsic defect size.Finally,the fatigue origin criterion was verified in three aspects.
文摘BACKGROUND Nosocomial fever of unknown origin(nFUO)is a frequent and challenging diagnostic entity,encompassing diverse infectious and non-infectious etiologies.Timely identification is crucial,yet evidence on the diagnostic accuracy of commonly employed sepsis screening tools and biomarkers remains sparse.We hypothesized that these tools and biomarkers measured at fever onset could distinguish infectious from non-infectious causes of nFUO in critically ill adults.AIM To evaluate the diagnostic utility of sepsis tools and biomarkers in identifying infectious causes of nFUO.METHODS This prospective observational study included patients admitted to the Acute Care Emergency Medicine Unit,Postgraduate Institute of Medical Education and Research,Chandigarh,India(July 2023 to December 2024).nFUO was defined by Durack and Street criteria.Diagnostic performance of sepsis screening tools(systemic inflammatory response syndrome,Sequential Organ Failure Assessment,quick Sequential Organ Failure Assessment,National Early Warning Score,and Modified Early Warning Score)and biomarkers[procalcitonin(PCT),C-reactive protein(CRP)]at fever onset was assessed using receiver operating characteristic curve analysis.RESULTS Of 80 cases(mean age 42.9±16.5 years;80% male),42.5% had infectious causes,38.7% non-infectious,and 18.8% remained undiagnosed.Pneumonia(26.2%)and bloodstream infections(11.2%)were the most common infectious etiologies,while central fever and thrombophlebitis(each 7.5%)were predominant among non-infectious causes.Sepsis tools showed poor diagnostic accuracy,with area under the receiver operating characteristic curve(AUC)values close to 0.5.PCT demonstrated modest performance(AUC=0.61;optimal cut-off:0.85μg/L),while CRP was paradoxically higher in non-infectious cases(AUC=0.45).Overall mortality was 20% and was highest among undiagnosed patients(33.3%).Fever duration and hospitalization length were significantly greater in infectious cases.CONCLUSION Sepsis tools,PCT,and CRP have limited utility in identifying infectious causes of nFUO in critically ill adults and should not solely guide initial decision-making.
基金supported by the National Natural Science Foundation of China(No.41972069)National Major Science and Technology Project on Deep Earth(No.2024ZD1001208)the China Geological Survey(No.DD20221645,DD20221648).
文摘There is no consensus on the tectonic evolution of the western Jiangnan Orogen(WJO)during 770-750 Ma.Thus,we reported zircon trace elements and U‐Pb‐Hf‐O isotopes and whole-rock geochemistry of the Neoproterozoic tuff located in Longsheng,northern Guangxi,in the WJO,to decipher their origin and tectonic setting.The SIMS U‐Pb zircon age yields a concordia age of 772.1±3.8 Ma,suggesting that the tuff layer formed at 770 Ma.Geochemical data of the tuff and its zircon exhibit continental arc signatures.Oxygen isotopes of the zircon show normal mantle zirconδ^(18)O zircon values of 4.59‰-5.50‰with an average of 5.24‰.The zircon yielded positive ε_(Hf)(t)values of 1.8-5.8 with two-stage model ages of 1.32-1.55 Ga.Based on these data and previous studies,the magma source for the tuff is inferred to have originated from the partial melting of the Mesoproterozoic juvenile crust,as the pre-existing arc materials and mixing with the mantle source under the extensional setting during 770-750 Ma triggered by the slab break-off.We infer that the presence of contemporaneous OIB-type and arc-like magmatism at ca.770-750 Ma along the WJO was related to the slab break-off.
文摘BACKGROUND Fever of unknown origin(FUO)remains a diagnostic challenge and was originally defined in 1961.Its classic criteria include fever≥38.3°C(≥101°F)on multiple occasions,fever lasting three weeks or longer,and a diagnosis after one week of inpatient evaluation.However,these criteria may not fully encompass the varied clinical presentations seen in resource-limited settings such as India.The adaptation of FUO definitions to local healthcare contexts is crucial for enhancing diagnostic accuracy and optimizing patient outcomes.AIM To investigate the applicability of revised FUO criteria in a tertiary care setting in India.METHODS This longitudinal-exploratory study at All India Institute of Medical Sciences Rishikesh(January 2018–December 2022)analyzed 228 adult patients with fever≥99.1°F lasting over three days.Patients diagnosed within three days of admission were excluded.Data were collected retrospectively and prospectively using predefined FUO definitions based on durations of nondiagnosis(3-21 days,>21 days),temperature ranges(99.1°F-100.9°F,≥101°F),and hospitalization durations(3-7 days,>7 days).Descriptive statistics and comparative tests(Fisher's exact test,χ2 test)evaluated outcomes across definitions.RESULTS Among the proposed FUO definitions,Definition B(fever lasting 3-21 days,temperatures between 99.1°F-100.9°F,hospitalization>7 days)predominated(40.8%),while only 2.2%met the classical criteria.Notably,36.5%of Definition B patients remained undiagnosed after 7-10 days,despite 94%undergoing diagnostic workups within 21 days.Infection emerged as the leading etiology across definitions,without significant variation in outcomes or mortality during hospitalization(χ2=27.937,P=0.142).CONCLUSION Adapting FUO criteria to local contexts improves diagnostic accuracy and treatment.Definition B(40.8%prevalence)showed practical utility,with higher mortality in patients discharged on empirical'Anti-tuberculosis therapy'.
文摘The origin of dolostone in the Middle Jurassic Buqu Formation of the Plateau Basin has been a subject of prolonged debate.This study combines detailed petrological observations with analyses of Mg-C-O isotopes and elements to constrain the origin of dolostones in the Buqu Formation.Petrography and cathodoluminescence(CL)examination identified three types of matrix dolostones:very finely to finely crystalline dolostone(D1),finely to medium crystalline dolostone(D2),and medium to coarsely crystalline dolostone(D3).The analysis of the diagenesis sequence reveals that D1 originated from the dolomitization of grainstone in the early diagenetic phase,whereas D2 and D3 resulted from the recrystallization of D1 during the later burial phase.The presence of high Na(>100 ppm),low Fe(<1000 ppm),low Mn(<250 ppm),positive Ce anomaly,LREE enrichment,stableδ^(26)Mg(-2.28‰to-2.04‰),andδ^(13)C(1.02‰-2.95‰)indicates that the early dolomitization fluid was oxidized seawater.As the crystal size increases(D1→D2→D3),the progressively rising Mn content and significantly negativeδ^(18)O(-10.72‰to-7.81‰)suggest that the dolostone has experienced modification and alteration by buried pore water in the later stages.The fluctuations in relative sea level during the sedimentary deposition of the Buqu Formation were reconstructed through the utilization of Na,Sr/Cu,Sr/Ba,Rb/Sr,∑REE,andδ^(13)C.It was observed that theδ^(26)Mg of dolostone closely mirrored the variations in sea level.The consistent trend of change confirms that sea level fluctuations control the formation and distribution of early dolostone.Frequent sea level rise and fall prompted the limestone deposited on the carbonate platform to be continuously transformed into dolostone,which accumulates over a long period to form large-scale thick dolostone.After the formation entered the burial stage,under the combined action of high Mg/Ca ratio pore water,high temperature,and high pressure,the early dolostone experienced the adjustment of burial dolomitization.This research offers a typical case study on the application of Mg-C-O isotope and elements to determine the origin of dolostone.This will aid in a more comprehensive understanding of the formation process of dolostone in ancient rock records.
基金the National Social Science Foundation of China’s Art Program“Study on the Transformation of Tang and Song Calligraphy through the Perspective of Media Change and Engraved Plate Printing”(Project No.2020BF00876).
文摘The origin of engraving and printing has a variety of points of view,especially the“early Tang Dynasty”has the most far-reaching impact.Based on media evolution theory,engraved printing as a new media technology is first used in secular culture,folk entertainment,and other fields,after a long period of development,the new medium was accepted by the ruling class,the mainstream society;the use of the media began to intervene in the real society.This reflects that the choice of new media by the society depends on the media itself and is intrinsically linked to the whole social communication environment.Therefore,from the point of view of media evolution,the view that engraving originated in the early Tang Dynasty is not in line with the logic of media evolution and is unreasonable.
基金Supported by the National Natural Science Foundation of China(42172166)National Natural Science Foundation and CNPC Joint Fund Project(U23B20154)CNPC-Southwest Petroleum University Science and Technology Cooperation Project(2020CX010000).
文摘This paper discusses the characteristics and formation mechanism of thin dolomite reservoirs in the lower submember of the second member of the Permian Maokou Formation(lower Mao 2 Member)in the Wusheng-Tongnan area of the Sichuan Basin,SW China,through comprehensive analysis of geological,geophysical and geochemical data.The reservoir rocks of the lower Mao 2 Member are dominated by porphyritic vuggy dolomite and calcareous dolomite or dolomitic limestone,which have typical karst characteristics of early diagenetic stage.The dolomites at the edge of the karst system and in the fillings have dissolved estuaries,and the dolomite breccia has micrite envelope and rim cement at the edge,indicating that dolomitization is earlier than the early diagenetic karstification.The shoal facies laminated dolomite is primarily formed by the seepage reflux dolomitization of moderate-salinity seawater.The key factors of reservoir formation are the bioclastic shoal deposition superimposed with seepgae reflux dolomitization and the karstification of early diagenetic stage,which are locally reformed by fractures and hydrothermal processes.The development of dolomite vuggy reservoir is closely related to the upward-shallowing sequence,and mainly occurs in the late highstand of the fourth-order cycle.Moreover,the size of dolomite is closely related to formation thickness,and it is concentrated in the formation thickness conversion area,followed by the thinner area.According to the understanding of insufficient accommodation space in the geomorphic highland and the migration of granular shoal to geomorphic lowland in the late highstand of the third-order cycle,it is proposed that the large-scale shoal-controlled dolomite reservoirs are distributed along structural highs and slopes,and the reservoir-forming model with shoal,dolomitization and karstification jointly controlled by the microgeomorphy and sea-level fluctuation in the sedimentary period is established.On this basis,the paleogeomorphology in the lower Mao 2 Member is restored using well-seismic data,and the reservoir distribution is predicted.The prediction results have been verified by the latest results of exploration wells and tests,which provide an important reference for the prediction of thin dolomite reservoirs under similar geological setting.
基金supported by a grant from Guangdong Provincial Natural Science Foundation of China(2023A15115012665).
文摘Disseminated mucormycosis is a life-threatening fungal infection with high mortality,particularly in immunocompromised patients.Early diagnosis and prompt intervention are crutial but often delayed due to nonspecific presentations.Many studies have highlighted the challenges in emergency settings,where atypical symptoms may lead to misdiagnosis.We report a rare case of disseminated mucormycosis originating from the stomach in a pregnancy-induced thrombocytopenia(PITP)patient,emphasizing rapid gastroscopy examination,histopathological confi rmation,multidisciplinary management,and high-risk factors for hospital-acquired gastrointestinal mucormycosis infection.
