Fine-grained sedimentary rocks have become a research focus as important reservoirs and source rocks for tight and shale oil and gas.Laminae development determines the accumulation and production of tight and shale oi...Fine-grained sedimentary rocks have become a research focus as important reservoirs and source rocks for tight and shale oil and gas.Laminae development determines the accumulation and production of tight and shale oil and gas in fine-grained rocks.However,due to the resolution limit of conventional logs,it is challenging to recognize the features of centimeter-scale laminae.To close this gap,complementary studies,including core observation,thin section,X-ray diffraction(XRD),conventional log analysis,and slabs of image logs,were conducted to unravel the centimeter-scale laminae.The laminae recognition models were built using well logs.The fine-grained rocks can be divided into laminated rocks(lamina thickness of<0.01 m),layered rocks(0.01-0.1 m),and massive rocks(no layer or layer spacing of>0.1 m)according to the laminae scale from core observations.According to the mineral superposition assemblages from thin-section observations,the laminated rocks can be further divided into binary,ternary,and multiple structures.The typical mineral components,slabs,and T2spectrum distributions of various lamina types are unraveled.The core can identify the centimeter-millimeter-scale laminae,and the thin section can identify the millimeter-micrometer-scale laminae.Furthermore,they can detect mineral types and their superposition sequence.Conventional logs can identify the meter-scale layers,whereas image logs and related slabs can identify the laminae variations at millimeter-centimeter scales.Therefore,the slab of image logs combined with thin sections can identify laminae assemblage characteristics,including the thickness and vertical assemblage.The identification and classification of lamina structure of various scales on a single well can be predicted using conventional logs,image logs,and slabs combined with thin sections.The layered rocks have better reservoir quality and oil-bearing potential than the massive and laminated rocks.The laminated rocks’binary lamina is better than the ternary and multiple layers due to the high content of felsic minerals.The abovementioned results build the prediction model for multiscale laminae structure using well logs,helping sweet spots prediction in the Permian Lucaogou Formation in the Jimusar Sag and fine-grained sedimentary rocks worldwide.展开更多
Novel fully biodegradable thermoplastic composite laminates reinforced with ultrathin wood laminae were prepared through a hot-pressing process by using two different thermoplastic starch(TPS)matrices.The microstructu...Novel fully biodegradable thermoplastic composite laminates reinforced with ultrathin wood laminae were prepared through a hot-pressing process by using two different thermoplastic starch(TPS)matrices.The microstructure and physical properties of the resulting unidirectional and bidirectional laminates were studied.The investigated materials presented a complex microstructure,in which the porosity of the wood laminae was almost entirely occluded by the polymer matrix.The mechanical behavior of the laminates was strongly affected by the obtained microstructure,and matrix penetration in wood pores led to biodegradable composites with elastic modulus and tensile strength higher than those of their constituents.Finally,thermal welding and thermoformability tests proved how these materials possess features typical of thermoplastic materials.展开更多
The Chang 73 sub-member of Triassic Yanchang Formation in the Ordos Basin was taken as an example and the lamina types and combinations,reservoir space features and shale oil enrichment patterns in organic-rich shale ...The Chang 73 sub-member of Triassic Yanchang Formation in the Ordos Basin was taken as an example and the lamina types and combinations,reservoir space features and shale oil enrichment patterns in organic-rich shale strata were investigated using core observation,thin section analysis,XRF element measurement,XRD analysis,SEM,high solution laser Raman spectroscopy analysis,and micro-FTIR spectroscopy analysis,etc.According to the mineral composition and thickness of the laminae,the Chang 73 organic-rich shales have four major types of laminae,tuff-rich lamina,organic-rich lamina,silt-grade feldspar-quartz lamina and clay lamina.They have two kinds of shale oil-bearing layers,"organic-rich lamina+silt-grade feldspar-quartz lamina"and"organic-rich lamina+tuff-rich lamina"layers.In the"organic-rich+silt-grade feldspar-quartz"laminae combination shale strata,oil was characterized by relative high maturation,and always filled in K-feldspar dissolution pores in the silt-grade feldspar-quartz laminae,forming oil generation,migration and accumulation process between laminae inside the organic shales.In the"organic-rich+tuff-rich lamina"binary laminae combination shale strata,however,the reservoir properties were poor in organic-rich shales,the oil maturation was relatively lower,and mainly accumulated in the intergranular pores of interbedded thin-layered sandstones.The oil generation,migration and accumulation mainly occurred between organic-rich shales and interbedded thin-layered sandstones.展开更多
Based on thin-section,argon-ion polished large-area imaging and nano-CT scanning data,the reservoir characteristics and genetic mechanisms of the Lower Silurian Longmaxi shale layers with different laminae and laminae...Based on thin-section,argon-ion polished large-area imaging and nano-CT scanning data,the reservoir characteristics and genetic mechanisms of the Lower Silurian Longmaxi shale layers with different laminae and laminae combinations in the Sichuan Basin were examined.It is found that the shale has two kinds of laminae,clayey lamina and silty lamina,which are different in single lamina thickness,composition,pore type and structure,plane porosity and pore size distribution.The clayey laminae are about 100μm thick each,over 15%in organic matter content,over 70%in quartz content,and higher in organic pore ratio and plane porosity.They have abundant bedding fractures and organic matter and organic pores connecting with each other to form a network.In contrast,the silty laminae are about 50μm thick each,5%to 15%in organic matter content,over 50%in carbonate content,higher in inorganic pore ratio,undeveloped in bedding fracture,and have organic matter and organic pores disconnected from each other.The formation of mud lamina and silt lamina may be related to the flourish of silicon-rich organisms.The mud lamina is formed during the intermittent period,and silt lamina is formed during the bloom period of silicon-rich organisms.The mud laminae and silt laminae can combine into three types of assemblages:strip-shaped silt,gradating sand-mud and sand-mud thin interlayers.The strip-shaped silt assemblage has the highest porosity and horizontal/vertical permeability ratio,followed by the gradating sand-mud assemblage and sand-mud thin interlayer assemblage.The difference in the content ratio of the mud laminae to silt laminae results in the difference in the horizontal/vertical permeability ratio.展开更多
Based on various test data, the composition, texture, structure and lamina types of gas-bearing shale were determined based on Well Wuxi 2 of the Silurian Longmaxi Formation in the Sichuan Basin. Four types of lamina,...Based on various test data, the composition, texture, structure and lamina types of gas-bearing shale were determined based on Well Wuxi 2 of the Silurian Longmaxi Formation in the Sichuan Basin. Four types of lamina, namely organic-rich lamina, organic-bearing lamina, clay lamina and silty lamina, are developed in the Longmaxi Formation of Well Wuxi 2, and they form 2 kinds of lamina set and 5 kinds of beds. Because of increasing supply of terrigenous clasts and enhancing hydrodynamics and associated oxygen levels, the contents of TOC and brittle mineral reduce and content of clay mineral increases gradually as the depth becomes shallow. Organic-rich lamina, organic-rich + organic-bearing lamina set and organic-rich bed dominate the small layers 1-3 of Member 1 of the Longmaxi Formation, suggesting anoxic and weak hydraulic depositional setting. Organic-rich lamina, along with organic-bearing lamina and silty lamina, appear in small layer 4, suggesting increased oxygenated and hydraulic level. Small layers 1-3 are the best interval and drilling target of shale gas exploration and development.展开更多
In this study,an in-depth analysis of the types,characteristics,and formation mechanisms of microlaminae and microscopic laminae was conducted in order to precisely examine the link or intersection of stratigraphy and...In this study,an in-depth analysis of the types,characteristics,and formation mechanisms of microlaminae and microscopic laminae was conducted in order to precisely examine the link or intersection of stratigraphy and petrology.This study was essentially a sedimentary examination of the minuteness-macro and micro-tiny layers between laminae and pore structure,as well as the types of structures and sedimentation.The results of this study bear important basic subject attributes and significance,as well as practical value for the basic theories and exploration applications of unconventional oil and gas geology.The quantitative data were obtained using the following:field macroscopic observations;measurements;intensive sampling processes;XRD mineral content analysis;scanning electron microscopy;high-power polarizing microscope observations;and micro-scale measurements.The quantitative parameters,such as laminae thicknesses,laminae properties,organic matter laminae,and laminae spatial distributions were unified within a framework,and the correlations among them were established for the purpose of forming a fine-grained deposition micro-laminae evaluation system.The results obtained in this research investigation established a basis for the classification of micro-laminae,and divided the micro-laminae into four categories and 20 sub-categories according to the development thicknesses,material compositions,organic matter content levels,and the spatial distributions of the micro-laminae.The classification scheme of the micro-laminae was divided into two categories and 12 sub-categories.Then,in accordance with the comprehensive characteristics of spatial morphology,the micro-laminae was further divided into the following categories:continuous horizontal laminae;near horizontal laminae;slow wavy laminae;wavy laminae;discontinuous laminae;and lenticular laminae.According to the structural properties of the laminae development,the micro-laminae was divided into the following categories:single laminae structures;laminated laminae structures;interlaminar structures;multiple mixed laminae structures;cyclic laminae structures;and progressive laminae structures.The research results were considered to be applicable for the scientific evaluations of reservoir spaces related to unconventional oil and gas resources.展开更多
The annual laminae gray level variations in the stalagmite TS9501 of Shihua Cave, Beijing are studied in detail. The environmental factors influencing the laminae gray level are also analyzed. The following conditions...The annual laminae gray level variations in the stalagmite TS9501 of Shihua Cave, Beijing are studied in detail. The environmental factors influencing the laminae gray level are also analyzed. The following conditions may be necessary to the study on the lamina gray level. A) The seasonal differences of climate in the studied area are strong. B) The cave has a rapid and simple hydrological connection with the surface, such that the gray level variation is great; therefore, climatic changes can be more clearly recorded in a stalagmite. C) No water from other sources due to lateral flow adds to the seepage over the cave. D) There are more organic impurities than inorganic ones, whose content changes distinctly with time in the sample. By comparison with the modern instrumental climate records, it was found that the gray level of laminae is mainly related to the air temperature, especially the summer mean temperature. Therefore, the gray level can be used as a proxy of the air temperature. The variation展开更多
The control of micro-wettability of pore-throat on shale oil occurrence in different types of reservoir spaces remains unclear.Take the shale oil reservoir of the Permian Lucaogou Formation in the Jimusar Sag,Junggar ...The control of micro-wettability of pore-throat on shale oil occurrence in different types of reservoir spaces remains unclear.Take the shale oil reservoir of the Permian Lucaogou Formation in the Jimusar Sag,Junggar Basin as an example,the reservoir space in laminated shale and the control of micro-wettability of pore-throat on shale oil occurrence were studied by using scanning electron microscope(SEM),multi-stage pyrolysis,quantitative fluorescence,nuclear magnetic resonance(NMR)and other techniques.The results show that there are mainly two types of laminated shale in the Lucaogou Formation,namely laminated shale rich in volcanic materials+terrigenous felsic,and laminated shale rich in volcanic materials+carbonate.The former type contains feldspar dissolution pores and intergranular pores,mainly with felsic mineral components around the pore-throats,which are water-wet and control the free shale oil.The latter type contains carbonate intercrystalline pores and organic pores,mainly with oil-wet mineral components around the pore-throats,which control the adsorbed shale oil.The oil-wet mineral components around the pore-throats are conducive to oil accumulation,but reduce the proportion of free oil.In the Lucaogou Formation,free oil,with high maturity and light quality,mainly occurs in the laminated shale rich in volcanic materials+terrigenous felsic.展开更多
According to the theory of sequence stratigraphy based on continental transgressive-regressive(T-R)cycles,a 500 m continuous core taken from the second member of Kongdian Formation(Kong 2 Member)of Paleogene in Well G...According to the theory of sequence stratigraphy based on continental transgressive-regressive(T-R)cycles,a 500 m continuous core taken from the second member of Kongdian Formation(Kong 2 Member)of Paleogene in Well G108-8 in the Cangdong Sag,Bohai Bay Basin,was tested and analyzed to clarify the high-frequency cycles of deep-water fine-grained sedimentary rocks in lacustrine basins.A logging vectorgraph in red pattern was plotted,and then a sequence stratigraphic framework with five-order high-frequency cycles was formed for the fine-grained sedimentary rocks in the Kong 2 Member.The high-frequency cycles of fine-grained sedimentary rocks were characterized by using different methods and at different scales.It is found that the fifth-order T cycles record a high content of terrigenous clastic minerals,a low paleosalinity,a relatively humid paleoclimate and a high density of laminae,while the fifth-order R cycles display a high content of carbonate minerals,a high paleosalinity,a dry paleoclimate and a low density of laminae.The changes in high-frequency cycles controlled the abundance and type of organic matter.The T cycles exhibit relatively high TOC and abundant endogenous organic matters in water in addition to terrigenous organic matters,implying a high primary productivity of lake for the generation and enrichment of shale oil.展开更多
The treatment of pathologies in the thoracic spine is a challenge. The periodic failure of pedicle screw insertion and anatomical variations make the search for an alternative to pedicle screws in thoracic spine surge...The treatment of pathologies in the thoracic spine is a challenge. The periodic failure of pedicle screw insertion and anatomical variations make the search for an alternative to pedicle screws in thoracic spine surgery necessary. The interlaminar crossed screws is a well-known and secure method for fusion in cervical spine, and in thoracic spine there used to be insufficient clinical data to support this technique, until now. We demonstrate in an initial series of 10 cases treated with interlaminar fusion in association of other fusion techniques in the thoracic spine with good results. Objective: Intralaminar screws have been shown to be a biomechanical salvage technique in the thoracic spine, especially in long cervicothoracic, thoracic and thoracolumbar fixation. The goals of this article are to demonstrate our initial experience and the range of indications for thoracic crossed intralaminar screws. Methods: In this article we describe our initial series performed at São Teotónio Hospital in Viseu, Portugal, and our results, and also provide a comprehensive review of the recent literature in the use of intralaminar crossed fixation.展开更多
Epidermolysis bullosa consist of a pattern of diseases which is mainly associated with genetic defects in the integrity of structures that cause the adhesion of the epidermis with the dermis,primarily called as the Ba...Epidermolysis bullosa consist of a pattern of diseases which is mainly associated with genetic defects in the integrity of structures that cause the adhesion of the epidermis with the dermis,primarily called as the Basement Membrane Zone.If the defect is associated with the lamina lucida of the basement membrane zone,it is called junctional epidermolysis bullosa(JEB).JEB is mainly inherited in an autosomal recessive manner.The characteristic feature of all the JEB subtypes is enamel hypoplasia.This article is aimed at identifying the main features of JEB in children.Fifty articles which were published between 2000 and 2022 were reviewed and the types,investigations and management of JEB are explained based on the existing literature.展开更多
Organic rich laminated shale is one type of favorable reservoirs for exploration and development of continental shale oil in China.However,with limited geological data,it is difficult to predict the spatial distributi...Organic rich laminated shale is one type of favorable reservoirs for exploration and development of continental shale oil in China.However,with limited geological data,it is difficult to predict the spatial distribution of laminated shale with great vertical heterogeneity.To solve this problem,taking Chang 73 sub-member in Yanchang Formation of Ordos Basin as an example,an idea of predicting lamina combinations by combining'conventional log data-mineral composition prediction-lamina combination type identification'has been worked out based on machine learning under supervision on the premise of adequate knowledge of characteristics of lamina mineral components.First,the main mineral components of the work area were figured out by analyzing core data,and the log data sensitive to changes of the mineral components was extracted;then machine learning was used to construct the mapping relationship between the two;based on the variations in mineral composition,the lamina combination types in typical wells of the research area were identified to verify the method.The results show the approach of'conventional log data-mineral composition prediction-lamina combination type identification'works well in identifying the types of shale lamina combinations.The approach was applied to Chang 73 sub-member in Yanchang Formation of Ordos Basin to find out planar distribution characteristics of the laminae.展开更多
The shape of leaf laminae exhibits considerable diversity and complexity that reflects adaptations to environmental factors such as ambient light and precipitation as well as phyletic legacy.Many leaves appear to be e...The shape of leaf laminae exhibits considerable diversity and complexity that reflects adaptations to environmental factors such as ambient light and precipitation as well as phyletic legacy.Many leaves appear to be elliptical which may represent a‘default’developmental condition.However,whether their geometry truly conforms to the ellipse equation(EE),i.e.,(x/a)^(2)+(y/b)^(2)=1,remains conjectural.One alternative is described by the superellipse equation(SE),a generalized version of EE,i.e.,|x/a|^(n)+|y/b|^(n)=1.To test the efficacy of EE versus SE to describe leaf geometry,the leaf shapes of two Michelia species(i.e.,M.cavaleriei var.platypetala,and M.maudiae),were investigated using 60 leaves from each species.Analysis shows that the majority of leaves(118 out of 120)had adjusted root-mean-square errors of<0.05 for the nonlinear fitting of SE to leaf geometry,i.e.,the mean absolute deviation from the polar point to leaf marginal points was smaller than 5%of the radius of a hypothesized circle with its area equaling leaf area.The estimates of n for the two species were<2,indicating that all sampled leaves conformed to SE and not to EE.This study confirms the existence of SE in leaves,linking this to its potential functional advantages,particularly the possible influence of leaf shape on hydraulic conductance.展开更多
BACKGROUND Irritable bowel syndrome (IBS) is one of the most common functional gastroenterological diseases characterized by abnormal visceral sensitivity and lowgrade inflammation. The role of Clostridium butyricum (...BACKGROUND Irritable bowel syndrome (IBS) is one of the most common functional gastroenterological diseases characterized by abnormal visceral sensitivity and lowgrade inflammation. The role of Clostridium butyricum (C. butyricum) in reducing intestinal low-grade inflammation via immune pathways has been well defined. However, the detailed mechanisms of the effects of C. butyricum on intestinal mucosal immunity, especially on immune cells of the lamina propria, remain unclear. Dendritic cells (DCs), which are important immune cells, secrete proinflammatory cytokines (IL-1β, IL-6, and others) and express T cell immunoglobulin and mucin domain-3 (TIM3), promoting proliferation and activation of DCs, and mediating Th1 and Th17 inflammatory responses. AIM To investigate the role of DCs in the development of IBS in a rat model and to understand the regulation of DCs after C. butyricum intervention. METHODS An IBS animal model was established using C57BL/6 mice, and C. butyricum was continuously administered via the intragastric route to simulate different intestinal immune states. Intestinal visceral hypersensitivity and histopathology were assessed using the abdominal withdrawal reflex (AWR) test and hematoxylin & eosin (H&E) staining, respectively. The expression of proinflammatory cytokines (IL-1β and IL-6) and TIM3 was analyzed by Western blot analysis and real-time PCR. Flow cytometry was applied to analyze the quantity, function, and membrane molecule TIM3 of the lamina propria dendritic cells (LPDCs). The regulatory effect of C. butyricum was verified in bone marrowderived dendritic cells by in vitro experiments. RESULTS The secretion of proinflammatory cytokines (IL-1β and IL-6) in mice with IBS was significantly increased compared with that of the control group, which suggested that the intestinal mucosa in mice with IBS was in a low-grade inflammatory state. The expression of CD11C+CD80+ and CD11c+TIM3+ in intestinal LPDCs in mice with IBS increased significantly. Meanwhile, the cytokines (IL-1β and IL-6) were significantly reduced after the intervention with probiotic C. butyricum. The amount and function of LPDCs and the TIM3 on the surface of the LPDCs were decreased with the alleviation of the intestinal inflammatory response. CONCLUSION The results suggest that C. butyricum regulates the amount and functional status of LPDCs in the intestinal mucosa of mice with IBS, and therefore modulates the local immune response in the intestine.展开更多
Our body is colonized by more than a hundred trillion commensals, represented by viruses, bacteria and fungi. This complex interaction has shown that the microbiome system contributes to the host's adaptation to i...Our body is colonized by more than a hundred trillion commensals, represented by viruses, bacteria and fungi. This complex interaction has shown that the microbiome system contributes to the host's adaptation to its environment, providing genes and functionality that give flexibility of diet and modulate the immune system in order not to reject these symbionts. In the intestine,specifically, the microbiota helps developing organ structures, participates of the metabolism of nutrients and induces immunity. Certain components of the microbiota have been shown to trigger inflammatory responses, whereas others, anti-inflammatory responses.The diversity and the composition of the microbiota,thus, play a key role in the maintenance of intestinal homeostasis and explain partially the link between intestinal microbiota changes and gut-related disorders in humans. Tight junction proteins are key molecules for determination of the paracellular permeability. In the context of intestinal inflammatory diseases, the intestinal barrier is compromised, and decreased expression and differential distribution of tight junction proteins is observed. It is still unclear what is the nature of the luminal or mucosal factors that affect the tight junctionproteins function, but the modulation of the immune cells found in the intestinal lamina propria is hypothesized as having a role in this modulation. In this review,we provide an overview of the current understanding of the interaction of the gut microbiota with the immune system in the development and maintenance of the intestinal barrier.展开更多
The gingiva, the masticatory portion of the oral mucosa, is excised and discarded frequently during routine dental treatments and following tooth extraction, dental crown lengthening, gingivectomy and periodontal surg...The gingiva, the masticatory portion of the oral mucosa, is excised and discarded frequently during routine dental treatments and following tooth extraction, dental crown lengthening, gingivectomy and periodontal surgeries. Subsequent to excision, healing eventually happens in a short time period after gingival surgery. Clinically, the gingival tissue can be collected very easily and, in the laboratory, it is also very easy to isolate gingival-derived mesenchymal stem cells (GMSCs) from this discarded gingival tissue. GMSCs, a stem cell population within the lamina propria of the gingival tissue, can be isolated from attached and free gingiva, inflamed gingival tissu-es, and from hyperplastic gingiva. Comparatively, they constitute more attractive alternatives to other dental-derived mesenchymal stem cells due to the availability and accessibility of gingival tissues. They have unique immunomodulatory functions and well-documented self-renewal and multipotent differentiation properties. They display positive signals for Stro-1, Oct-4 and SSEA-4 pluripotency-associated markers, with some co-expre-ssing Oct4/Stro-1 or Oct-4/SSEA-4. They should be considered as the best stem cell source for cell-based therapies and regenerative dentistry. The clinical use of GMSCs for regenerative dentistry represents an attrac-tive therapeutic modality. However, numerous biological and technical challenges need to be addressed prior to considering transplantation approaches of GMSCs as clinically realistic therapies for humans.展开更多
基金National Natural Science Foundation of China(Grant No.42002133,42072150)Science Foundation of China University of Petroleum,Beijing(No.2462021YXZZ003)the Strategic Cooperation Technology Projects of CNPC and CUPB(ZLZX2020-01-06)for the financial supports and permissions to publish this paper
文摘Fine-grained sedimentary rocks have become a research focus as important reservoirs and source rocks for tight and shale oil and gas.Laminae development determines the accumulation and production of tight and shale oil and gas in fine-grained rocks.However,due to the resolution limit of conventional logs,it is challenging to recognize the features of centimeter-scale laminae.To close this gap,complementary studies,including core observation,thin section,X-ray diffraction(XRD),conventional log analysis,and slabs of image logs,were conducted to unravel the centimeter-scale laminae.The laminae recognition models were built using well logs.The fine-grained rocks can be divided into laminated rocks(lamina thickness of<0.01 m),layered rocks(0.01-0.1 m),and massive rocks(no layer or layer spacing of>0.1 m)according to the laminae scale from core observations.According to the mineral superposition assemblages from thin-section observations,the laminated rocks can be further divided into binary,ternary,and multiple structures.The typical mineral components,slabs,and T2spectrum distributions of various lamina types are unraveled.The core can identify the centimeter-millimeter-scale laminae,and the thin section can identify the millimeter-micrometer-scale laminae.Furthermore,they can detect mineral types and their superposition sequence.Conventional logs can identify the meter-scale layers,whereas image logs and related slabs can identify the laminae variations at millimeter-centimeter scales.Therefore,the slab of image logs combined with thin sections can identify laminae assemblage characteristics,including the thickness and vertical assemblage.The identification and classification of lamina structure of various scales on a single well can be predicted using conventional logs,image logs,and slabs combined with thin sections.The layered rocks have better reservoir quality and oil-bearing potential than the massive and laminated rocks.The laminated rocks’binary lamina is better than the ternary and multiple layers due to the high content of felsic minerals.The abovementioned results build the prediction model for multiscale laminae structure using well logs,helping sweet spots prediction in the Permian Lucaogou Formation in the Jimusar Sag and fine-grained sedimentary rocks worldwide.
文摘Novel fully biodegradable thermoplastic composite laminates reinforced with ultrathin wood laminae were prepared through a hot-pressing process by using two different thermoplastic starch(TPS)matrices.The microstructure and physical properties of the resulting unidirectional and bidirectional laminates were studied.The investigated materials presented a complex microstructure,in which the porosity of the wood laminae was almost entirely occluded by the polymer matrix.The mechanical behavior of the laminates was strongly affected by the obtained microstructure,and matrix penetration in wood pores led to biodegradable composites with elastic modulus and tensile strength higher than those of their constituents.Finally,thermal welding and thermoformability tests proved how these materials possess features typical of thermoplastic materials.
基金Supported by the National Natural Fund Petrochemical Joint Fund Key Project(U1762217)Fundamental Scientific Research Operations Project of China Central Universities(19CX02009A)
文摘The Chang 73 sub-member of Triassic Yanchang Formation in the Ordos Basin was taken as an example and the lamina types and combinations,reservoir space features and shale oil enrichment patterns in organic-rich shale strata were investigated using core observation,thin section analysis,XRF element measurement,XRD analysis,SEM,high solution laser Raman spectroscopy analysis,and micro-FTIR spectroscopy analysis,etc.According to the mineral composition and thickness of the laminae,the Chang 73 organic-rich shales have four major types of laminae,tuff-rich lamina,organic-rich lamina,silt-grade feldspar-quartz lamina and clay lamina.They have two kinds of shale oil-bearing layers,"organic-rich lamina+silt-grade feldspar-quartz lamina"and"organic-rich lamina+tuff-rich lamina"layers.In the"organic-rich+silt-grade feldspar-quartz"laminae combination shale strata,oil was characterized by relative high maturation,and always filled in K-feldspar dissolution pores in the silt-grade feldspar-quartz laminae,forming oil generation,migration and accumulation process between laminae inside the organic shales.In the"organic-rich+tuff-rich lamina"binary laminae combination shale strata,however,the reservoir properties were poor in organic-rich shales,the oil maturation was relatively lower,and mainly accumulated in the intergranular pores of interbedded thin-layered sandstones.The oil generation,migration and accumulation mainly occurred between organic-rich shales and interbedded thin-layered sandstones.
基金Supported by China National Science and Technology Major Project(2017ZX05035-001)National Natural Science Fund Project(41572079)
文摘Based on thin-section,argon-ion polished large-area imaging and nano-CT scanning data,the reservoir characteristics and genetic mechanisms of the Lower Silurian Longmaxi shale layers with different laminae and laminae combinations in the Sichuan Basin were examined.It is found that the shale has two kinds of laminae,clayey lamina and silty lamina,which are different in single lamina thickness,composition,pore type and structure,plane porosity and pore size distribution.The clayey laminae are about 100μm thick each,over 15%in organic matter content,over 70%in quartz content,and higher in organic pore ratio and plane porosity.They have abundant bedding fractures and organic matter and organic pores connecting with each other to form a network.In contrast,the silty laminae are about 50μm thick each,5%to 15%in organic matter content,over 50%in carbonate content,higher in inorganic pore ratio,undeveloped in bedding fracture,and have organic matter and organic pores disconnected from each other.The formation of mud lamina and silt lamina may be related to the flourish of silicon-rich organisms.The mud lamina is formed during the intermittent period,and silt lamina is formed during the bloom period of silicon-rich organisms.The mud laminae and silt laminae can combine into three types of assemblages:strip-shaped silt,gradating sand-mud and sand-mud thin interlayers.The strip-shaped silt assemblage has the highest porosity and horizontal/vertical permeability ratio,followed by the gradating sand-mud assemblage and sand-mud thin interlayer assemblage.The difference in the content ratio of the mud laminae to silt laminae results in the difference in the horizontal/vertical permeability ratio.
基金Supported by the National Natural Science Foundation of China(4160211941572079)
文摘Based on various test data, the composition, texture, structure and lamina types of gas-bearing shale were determined based on Well Wuxi 2 of the Silurian Longmaxi Formation in the Sichuan Basin. Four types of lamina, namely organic-rich lamina, organic-bearing lamina, clay lamina and silty lamina, are developed in the Longmaxi Formation of Well Wuxi 2, and they form 2 kinds of lamina set and 5 kinds of beds. Because of increasing supply of terrigenous clasts and enhancing hydrodynamics and associated oxygen levels, the contents of TOC and brittle mineral reduce and content of clay mineral increases gradually as the depth becomes shallow. Organic-rich lamina, organic-rich + organic-bearing lamina set and organic-rich bed dominate the small layers 1-3 of Member 1 of the Longmaxi Formation, suggesting anoxic and weak hydraulic depositional setting. Organic-rich lamina, along with organic-bearing lamina and silty lamina, appear in small layer 4, suggesting increased oxygenated and hydraulic level. Small layers 1-3 are the best interval and drilling target of shale gas exploration and development.
文摘In this study,an in-depth analysis of the types,characteristics,and formation mechanisms of microlaminae and microscopic laminae was conducted in order to precisely examine the link or intersection of stratigraphy and petrology.This study was essentially a sedimentary examination of the minuteness-macro and micro-tiny layers between laminae and pore structure,as well as the types of structures and sedimentation.The results of this study bear important basic subject attributes and significance,as well as practical value for the basic theories and exploration applications of unconventional oil and gas geology.The quantitative data were obtained using the following:field macroscopic observations;measurements;intensive sampling processes;XRD mineral content analysis;scanning electron microscopy;high-power polarizing microscope observations;and micro-scale measurements.The quantitative parameters,such as laminae thicknesses,laminae properties,organic matter laminae,and laminae spatial distributions were unified within a framework,and the correlations among them were established for the purpose of forming a fine-grained deposition micro-laminae evaluation system.The results obtained in this research investigation established a basis for the classification of micro-laminae,and divided the micro-laminae into four categories and 20 sub-categories according to the development thicknesses,material compositions,organic matter content levels,and the spatial distributions of the micro-laminae.The classification scheme of the micro-laminae was divided into two categories and 12 sub-categories.Then,in accordance with the comprehensive characteristics of spatial morphology,the micro-laminae was further divided into the following categories:continuous horizontal laminae;near horizontal laminae;slow wavy laminae;wavy laminae;discontinuous laminae;and lenticular laminae.According to the structural properties of the laminae development,the micro-laminae was divided into the following categories:single laminae structures;laminated laminae structures;interlaminar structures;multiple mixed laminae structures;cyclic laminae structures;and progressive laminae structures.The research results were considered to be applicable for the scientific evaluations of reservoir spaces related to unconventional oil and gas resources.
文摘The annual laminae gray level variations in the stalagmite TS9501 of Shihua Cave, Beijing are studied in detail. The environmental factors influencing the laminae gray level are also analyzed. The following conditions may be necessary to the study on the lamina gray level. A) The seasonal differences of climate in the studied area are strong. B) The cave has a rapid and simple hydrological connection with the surface, such that the gray level variation is great; therefore, climatic changes can be more clearly recorded in a stalagmite. C) No water from other sources due to lateral flow adds to the seepage over the cave. D) There are more organic impurities than inorganic ones, whose content changes distinctly with time in the sample. By comparison with the modern instrumental climate records, it was found that the gray level of laminae is mainly related to the air temperature, especially the summer mean temperature. Therefore, the gray level can be used as a proxy of the air temperature. The variation
基金Supported by the National Natural Scienceof China(42072161,41821002)Central University Basic Research Project(22CX07008A)。
文摘The control of micro-wettability of pore-throat on shale oil occurrence in different types of reservoir spaces remains unclear.Take the shale oil reservoir of the Permian Lucaogou Formation in the Jimusar Sag,Junggar Basin as an example,the reservoir space in laminated shale and the control of micro-wettability of pore-throat on shale oil occurrence were studied by using scanning electron microscope(SEM),multi-stage pyrolysis,quantitative fluorescence,nuclear magnetic resonance(NMR)and other techniques.The results show that there are mainly two types of laminated shale in the Lucaogou Formation,namely laminated shale rich in volcanic materials+terrigenous felsic,and laminated shale rich in volcanic materials+carbonate.The former type contains feldspar dissolution pores and intergranular pores,mainly with felsic mineral components around the pore-throats,which are water-wet and control the free shale oil.The latter type contains carbonate intercrystalline pores and organic pores,mainly with oil-wet mineral components around the pore-throats,which control the adsorbed shale oil.The oil-wet mineral components around the pore-throats are conducive to oil accumulation,but reduce the proportion of free oil.In the Lucaogou Formation,free oil,with high maturity and light quality,mainly occurs in the laminated shale rich in volcanic materials+terrigenous felsic.
基金Supported by the National Major Research and Development Project(2020YFA0710504,2022YFF0801204)PetroChina Science and Technology Major Project(2019E-26)。
文摘According to the theory of sequence stratigraphy based on continental transgressive-regressive(T-R)cycles,a 500 m continuous core taken from the second member of Kongdian Formation(Kong 2 Member)of Paleogene in Well G108-8 in the Cangdong Sag,Bohai Bay Basin,was tested and analyzed to clarify the high-frequency cycles of deep-water fine-grained sedimentary rocks in lacustrine basins.A logging vectorgraph in red pattern was plotted,and then a sequence stratigraphic framework with five-order high-frequency cycles was formed for the fine-grained sedimentary rocks in the Kong 2 Member.The high-frequency cycles of fine-grained sedimentary rocks were characterized by using different methods and at different scales.It is found that the fifth-order T cycles record a high content of terrigenous clastic minerals,a low paleosalinity,a relatively humid paleoclimate and a high density of laminae,while the fifth-order R cycles display a high content of carbonate minerals,a high paleosalinity,a dry paleoclimate and a low density of laminae.The changes in high-frequency cycles controlled the abundance and type of organic matter.The T cycles exhibit relatively high TOC and abundant endogenous organic matters in water in addition to terrigenous organic matters,implying a high primary productivity of lake for the generation and enrichment of shale oil.
文摘The treatment of pathologies in the thoracic spine is a challenge. The periodic failure of pedicle screw insertion and anatomical variations make the search for an alternative to pedicle screws in thoracic spine surgery necessary. The interlaminar crossed screws is a well-known and secure method for fusion in cervical spine, and in thoracic spine there used to be insufficient clinical data to support this technique, until now. We demonstrate in an initial series of 10 cases treated with interlaminar fusion in association of other fusion techniques in the thoracic spine with good results. Objective: Intralaminar screws have been shown to be a biomechanical salvage technique in the thoracic spine, especially in long cervicothoracic, thoracic and thoracolumbar fixation. The goals of this article are to demonstrate our initial experience and the range of indications for thoracic crossed intralaminar screws. Methods: In this article we describe our initial series performed at São Teotónio Hospital in Viseu, Portugal, and our results, and also provide a comprehensive review of the recent literature in the use of intralaminar crossed fixation.
文摘Epidermolysis bullosa consist of a pattern of diseases which is mainly associated with genetic defects in the integrity of structures that cause the adhesion of the epidermis with the dermis,primarily called as the Basement Membrane Zone.If the defect is associated with the lamina lucida of the basement membrane zone,it is called junctional epidermolysis bullosa(JEB).JEB is mainly inherited in an autosomal recessive manner.The characteristic feature of all the JEB subtypes is enamel hypoplasia.This article is aimed at identifying the main features of JEB in children.Fifty articles which were published between 2000 and 2022 were reviewed and the types,investigations and management of JEB are explained based on the existing literature.
基金co-supported by the National Natural Science Foundation of China(Grant Nos.U1762217,42072161)。
文摘Organic rich laminated shale is one type of favorable reservoirs for exploration and development of continental shale oil in China.However,with limited geological data,it is difficult to predict the spatial distribution of laminated shale with great vertical heterogeneity.To solve this problem,taking Chang 73 sub-member in Yanchang Formation of Ordos Basin as an example,an idea of predicting lamina combinations by combining'conventional log data-mineral composition prediction-lamina combination type identification'has been worked out based on machine learning under supervision on the premise of adequate knowledge of characteristics of lamina mineral components.First,the main mineral components of the work area were figured out by analyzing core data,and the log data sensitive to changes of the mineral components was extracted;then machine learning was used to construct the mapping relationship between the two;based on the variations in mineral composition,the lamina combination types in typical wells of the research area were identified to verify the method.The results show the approach of'conventional log data-mineral composition prediction-lamina combination type identification'works well in identifying the types of shale lamina combinations.The approach was applied to Chang 73 sub-member in Yanchang Formation of Ordos Basin to find out planar distribution characteristics of the laminae.
文摘The shape of leaf laminae exhibits considerable diversity and complexity that reflects adaptations to environmental factors such as ambient light and precipitation as well as phyletic legacy.Many leaves appear to be elliptical which may represent a‘default’developmental condition.However,whether their geometry truly conforms to the ellipse equation(EE),i.e.,(x/a)^(2)+(y/b)^(2)=1,remains conjectural.One alternative is described by the superellipse equation(SE),a generalized version of EE,i.e.,|x/a|^(n)+|y/b|^(n)=1.To test the efficacy of EE versus SE to describe leaf geometry,the leaf shapes of two Michelia species(i.e.,M.cavaleriei var.platypetala,and M.maudiae),were investigated using 60 leaves from each species.Analysis shows that the majority of leaves(118 out of 120)had adjusted root-mean-square errors of<0.05 for the nonlinear fitting of SE to leaf geometry,i.e.,the mean absolute deviation from the polar point to leaf marginal points was smaller than 5%of the radius of a hypothesized circle with its area equaling leaf area.The estimates of n for the two species were<2,indicating that all sampled leaves conformed to SE and not to EE.This study confirms the existence of SE in leaves,linking this to its potential functional advantages,particularly the possible influence of leaf shape on hydraulic conductance.
基金Supported by the National Natural Science Foundation of China,No.81770538 and No.81570485Key Research and Development Program of Shandong Province,No.2017CXGC1215
文摘BACKGROUND Irritable bowel syndrome (IBS) is one of the most common functional gastroenterological diseases characterized by abnormal visceral sensitivity and lowgrade inflammation. The role of Clostridium butyricum (C. butyricum) in reducing intestinal low-grade inflammation via immune pathways has been well defined. However, the detailed mechanisms of the effects of C. butyricum on intestinal mucosal immunity, especially on immune cells of the lamina propria, remain unclear. Dendritic cells (DCs), which are important immune cells, secrete proinflammatory cytokines (IL-1β, IL-6, and others) and express T cell immunoglobulin and mucin domain-3 (TIM3), promoting proliferation and activation of DCs, and mediating Th1 and Th17 inflammatory responses. AIM To investigate the role of DCs in the development of IBS in a rat model and to understand the regulation of DCs after C. butyricum intervention. METHODS An IBS animal model was established using C57BL/6 mice, and C. butyricum was continuously administered via the intragastric route to simulate different intestinal immune states. Intestinal visceral hypersensitivity and histopathology were assessed using the abdominal withdrawal reflex (AWR) test and hematoxylin & eosin (H&E) staining, respectively. The expression of proinflammatory cytokines (IL-1β and IL-6) and TIM3 was analyzed by Western blot analysis and real-time PCR. Flow cytometry was applied to analyze the quantity, function, and membrane molecule TIM3 of the lamina propria dendritic cells (LPDCs). The regulatory effect of C. butyricum was verified in bone marrowderived dendritic cells by in vitro experiments. RESULTS The secretion of proinflammatory cytokines (IL-1β and IL-6) in mice with IBS was significantly increased compared with that of the control group, which suggested that the intestinal mucosa in mice with IBS was in a low-grade inflammatory state. The expression of CD11C+CD80+ and CD11c+TIM3+ in intestinal LPDCs in mice with IBS increased significantly. Meanwhile, the cytokines (IL-1β and IL-6) were significantly reduced after the intervention with probiotic C. butyricum. The amount and function of LPDCs and the TIM3 on the surface of the LPDCs were decreased with the alleviation of the intestinal inflammatory response. CONCLUSION The results suggest that C. butyricum regulates the amount and functional status of LPDCs in the intestinal mucosa of mice with IBS, and therefore modulates the local immune response in the intestine.
文摘Our body is colonized by more than a hundred trillion commensals, represented by viruses, bacteria and fungi. This complex interaction has shown that the microbiome system contributes to the host's adaptation to its environment, providing genes and functionality that give flexibility of diet and modulate the immune system in order not to reject these symbionts. In the intestine,specifically, the microbiota helps developing organ structures, participates of the metabolism of nutrients and induces immunity. Certain components of the microbiota have been shown to trigger inflammatory responses, whereas others, anti-inflammatory responses.The diversity and the composition of the microbiota,thus, play a key role in the maintenance of intestinal homeostasis and explain partially the link between intestinal microbiota changes and gut-related disorders in humans. Tight junction proteins are key molecules for determination of the paracellular permeability. In the context of intestinal inflammatory diseases, the intestinal barrier is compromised, and decreased expression and differential distribution of tight junction proteins is observed. It is still unclear what is the nature of the luminal or mucosal factors that affect the tight junctionproteins function, but the modulation of the immune cells found in the intestinal lamina propria is hypothesized as having a role in this modulation. In this review,we provide an overview of the current understanding of the interaction of the gut microbiota with the immune system in the development and maintenance of the intestinal barrier.
文摘The gingiva, the masticatory portion of the oral mucosa, is excised and discarded frequently during routine dental treatments and following tooth extraction, dental crown lengthening, gingivectomy and periodontal surgeries. Subsequent to excision, healing eventually happens in a short time period after gingival surgery. Clinically, the gingival tissue can be collected very easily and, in the laboratory, it is also very easy to isolate gingival-derived mesenchymal stem cells (GMSCs) from this discarded gingival tissue. GMSCs, a stem cell population within the lamina propria of the gingival tissue, can be isolated from attached and free gingiva, inflamed gingival tissu-es, and from hyperplastic gingiva. Comparatively, they constitute more attractive alternatives to other dental-derived mesenchymal stem cells due to the availability and accessibility of gingival tissues. They have unique immunomodulatory functions and well-documented self-renewal and multipotent differentiation properties. They display positive signals for Stro-1, Oct-4 and SSEA-4 pluripotency-associated markers, with some co-expre-ssing Oct4/Stro-1 or Oct-4/SSEA-4. They should be considered as the best stem cell source for cell-based therapies and regenerative dentistry. The clinical use of GMSCs for regenerative dentistry represents an attrac-tive therapeutic modality. However, numerous biological and technical challenges need to be addressed prior to considering transplantation approaches of GMSCs as clinically realistic therapies for humans.