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The effects of various factors on spontaneous imbibition in tight oil reservoirs
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作者 Cheng Liu Tian-Ru Wang +3 位作者 Qing You Yue-Chun Du Guang Zhao Cai-Li Dai 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期315-326,共12页
Slickwater fracturing fluids have gained widespread application in the development of tight oil reservoirs. After the fracturing process, the active components present in slickwater can directly induce spontaneous imb... Slickwater fracturing fluids have gained widespread application in the development of tight oil reservoirs. After the fracturing process, the active components present in slickwater can directly induce spontaneous imbibition within the reservoir. Several variables influence the eventual recovery rate within this procedure, including slickwater composition, formation temperature, degree of reservoir fracture development, and the reservoir characteristics. Nonetheless, the underlying mechanisms governing these influences remain relatively understudied. In this investigation, using the Chang-7 block of the Changqing Oilfield as the study site, we employ EM-30 slickwater fracturing fluid to explore the effects of the drag-reducing agent concentration, imbibition temperature, core permeability, and core fracture development on spontaneous imbibition. An elevated drag-reducing agent concentration is observed to diminish the degree of medium and small pore utilization. Furthermore, higher temperatures and an augmented permeability enhance the fluid flow properties, thereby contributing to an increased utilization rate across all pore sizes. Reduced fracture development results in a lower fluid utilization across diverse pore types. This study deepens our understanding of the pivotal factors affecting spontaneous imbibition in tight reservoirs following fracturing. The findings act as theoretical, technical, and scientific foundations for optimizing fracturing strategies in tight oil reservoir transformations. 展开更多
关键词 Tight oil reservoir spontaneous imbibition Nuclear magnetic resonance Slickwater fracturing fluid Fluid utilization degree
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Effect and Mechanism of Rare Earth Hydrotalcite Inhibiting Coal Spontaneous Combustion
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作者 张小娟 LIU Bo +1 位作者 罗振敏 SUN Lu 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第1期50-59,共10页
A hydrotalcite(layered double hydroxide, LDH) inhibitor which is suitable for the whole process of coal spontaneous combustion and a LDH inhibitor containing rare earth lanthanum elements were prepared. The inhibition... A hydrotalcite(layered double hydroxide, LDH) inhibitor which is suitable for the whole process of coal spontaneous combustion and a LDH inhibitor containing rare earth lanthanum elements were prepared. The inhibition effect and mechanism were analyzed by scanning electron microscopy(SEM),X-ray diffraction(XRD), thermal performance analysis, in-situ diffuse reflectance infrared spectroscopy and temperature-programmed experiment. The results have shown that the inhibitor containing lanthanum can play a good inhibitory role in every stage of coal oxidation. During the slow oxidation of coal samples, the inhibitor containing lanthanum ions can slow down the oxidation process of coal and increase the initial temperature of coal spontaneous combustion. At the same time, because the hydroxyl groups in LDHs are connected with-COO-groups on the coal surface through hydrogen bonds, the stability of coal is improved. With the increase of temperature, LDHs can remove interlayer water molecules and reduce the surface temperature of coal. CO release rate of coal samples decreases significantly after adding inhibitor containing lanthanum element, and the maximum inhibition rate of the inhibitor is 58.1%. 展开更多
关键词 rare earth HYDROTALCITE coal spontaneous combustion MECHANISM
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A novel predictor of unsustained return of spontaneous circulation in cardiac arrest patients through a combination of capnography and pulse oximetry: a multicenter observational study
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作者 Jing Yang Hanqi Tang +11 位作者 Shihuan Shao Feng Xu Yangyang Fu Shengyong Xu Chen Li Yan Li Yang Liu Joseph Harold Walline Huadong Zhu Yuguo Chen Xuezhong Yu Jun Xu 《World Journal of Emergency Medicine》 SCIE CAS CSCD 2024年第1期16-22,共7页
BACKGROUND:Unsustained return of spontaneous circulation(ROSC)is a critical barrier to survival in cardiac arrest patients.This study examined whether end-tidal carbon dioxide(ETCO_(2))and pulse oximetry photoplethysm... BACKGROUND:Unsustained return of spontaneous circulation(ROSC)is a critical barrier to survival in cardiac arrest patients.This study examined whether end-tidal carbon dioxide(ETCO_(2))and pulse oximetry photoplethysmogram(POP)parameters can be used to identify unsustained ROSC.METHODS:We conducted a multicenter observational prospective cohort study of consecutive patients with cardiac arrest from 2013 to 2014.Patients’general information,ETCO_(2),and POP parameters were collected and statistically analyzed.RESULTS:The included 105 ROSC episodes(from 80 cardiac arrest patients)comprised 51 sustained ROSC episodes and 54 unsustained ROSC episodes.The 24-hour survival rate was significantly higher in the sustained ROSC group than in the unsustained ROSC group(29.2%vs.9.4%,P<0.05).The logistic regression analysis showed that the difference between after and before ROSC in ETCO_(2)(ΔETCO_(2))and the difference between after and before ROCS in area under the curve of POP(ΔAUCp)were independently associated with sustained ROSC(odds ratio[OR]=0.931,95%confi dence interval[95%CI]0.881-0.984,P=0.011 and OR=0.998,95%CI 0.997-0.999,P<0.001).The area under the receiver operating characteristic curve ofΔETCO_(2),ΔAUCp,and the combination of both to predict unsustained ROSC were 0.752(95%CI 0.660-0.844),0.883(95%CI 0.818-0.948),and 0.902(95%CI 0.842-0.962),respectively.CONCLUSION:Patients with unsustained ROSC have a poor prognosis.The combination ofΔETCO_(2) andΔAUCp showed signifi cant predictive value for unsustained ROSC. 展开更多
关键词 Return of spontaneous circulation Pulse oximetry photoplethysmogram End-tidal carbon dioxide Cardiac arrest Cardiopulmonary resuscitation
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Underlying anti-hypertensive mechanism of the Mizuhopecten yessoensis derived peptide NCW in spontaneously hypertensive rats via widely targeted kidney metabolomics
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作者 Wenjun Xue Wenzhu Zhao +1 位作者 Sijia Wu Zhipeng Yu 《Food Science and Human Wellness》 SCIE CSCD 2024年第1期472-481,共10页
The angiotensin-converting enzyme(ACE)inhibitory peptide NCW derived from Mizuhopecten yessoensis has been demonstrated to have significant in vivo anti-hypertensive effects,however,its anti-hypertensive mechanism is ... The angiotensin-converting enzyme(ACE)inhibitory peptide NCW derived from Mizuhopecten yessoensis has been demonstrated to have significant in vivo anti-hypertensive effects,however,its anti-hypertensive mechanism is still not fully clarified.This study established a UPLC-Q-TRAP-MS/MS-based widely targeted kidney metabolomics approach to explore the changes of kidney metabolic profiles and to clarify the antihypertensive mechanism of peptide NCW in spontaneously hypertensive rats(SHRs).Multivariate statistical analysis indicated that the kidney metabolic profiles were clearly separated between the SHR-NCW and SHRUntreated groups.A total of 85 metabolites were differentially regulated,and 16 metabolites were identified as potential kidney biomarkers,e.g.,3-hydroxybutyrate,malonic acid,deoxycytidine,and L-aspartic acid.The peptide NCW might regulate kidney metabolic disorder of SHRs to alleviate hypertension by suppressing inflammation and improving nitric oxide production under the regulation of linoleic acid metabolism,folate related pathways,synthesis and degradation of ketone bodies,pyrimidine metabolism,β-alanine metabolism,and retinal metabolism. 展开更多
关键词 ACE inhibitory peptide KIDNEY MECHANISM Metabolomics spontaneously hypertensive rats
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Correction:Establishment of a prediction model for prehospital return of spontaneous circulation in out-of-hospital patients with cardiac arrest
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作者 Jing-Jing Wang Qiang Zhou +5 位作者 Zhen-Hua Huang Yong Han Chong-Zhen Qin Zhong-Qing Chen Xiao-Yong Xiao Zhe Deng 《World Journal of Cardiology》 2024年第4期215-216,共2页
This is an erratum to an already published paper named“Establishment of a prediction model for prehospital return of spontaneous circulation in out-ofhospital patients with cardiac arrest”.We found errors in the aff... This is an erratum to an already published paper named“Establishment of a prediction model for prehospital return of spontaneous circulation in out-ofhospital patients with cardiac arrest”.We found errors in the affiliated institution of the authors.We apologize for our unintentional mistake.Please note,these changes do not affect our results. 展开更多
关键词 Cardiac arrest Cardiopulmonary resuscitation Recovery spontaneous circulation Logistic regression analysis Predictive model
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Spontaneous coronary artery rupture after lung cancer surgery:A case report and review of literature
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作者 Ying-Ding Ruan Jian-Wei Han 《World Journal of Cardiology》 2024年第2期92-97,共6页
BACKGROUND Spontaneous coronary artery rupture(SCAR)is a rare and life-threatening complication after lung cancer surgery.We present a case of SCAR following left upper lobectomy,successfully managed through emergency... BACKGROUND Spontaneous coronary artery rupture(SCAR)is a rare and life-threatening complication after lung cancer surgery.We present a case of SCAR following left upper lobectomy,successfully managed through emergency thoracotomy and coronary artery ligation.CASE SUMMARY A 61-year-old male patient underwent left upper lobectomy and mediastinal lymph node dissection for lung cancer.The surgery was performed using singleport video-assisted thoracoscopic surgery,and there were no observed complications during the procedure.However,19 h after surgery,the patient experienced chest discomfort and subsequently developed severe symptoms,including nausea,vomiting,and a drop in blood pressure.Urgent measures were taken,leading to the diagnosis of SCAR.The patient underwent emergency thoracotomy and coronary artery ligation,successfully stopping the bleeding and stabilizing the condition.Despite postoperative complications,the patient made a successful recovery and was discharged from the hospital.CONCLUSION SCAR is a rare but life-threatening complication following lung cancer surgery.Immediate thoracotomy has been shown to be a life-saving measure,while stenting is not the preferred initial approach. 展开更多
关键词 spontaneous coronary artery rupture Lung cancer SURGERY Case report
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Populational change of CD4^(+)CD25^(+)Treg cells is responsible for the synergistic effect of the combination of RAMP2 with baicalin in treating recurrent spontaneous abortion mouse models
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作者 Cong Chen Zhuo-Lan Li +2 位作者 Jing-Tian Guo Wen-Yao Xue Wei Guo 《Traditional Medicine Research》 2024年第8期59-66,共8页
Background: The absence of a safe and effective therapy for recurrent spontaneous abortion due to a maternofetal failure in immunological tolerance remains an intractable clinical obstacle for surgeons. Recently, trad... Background: The absence of a safe and effective therapy for recurrent spontaneous abortion due to a maternofetal failure in immunological tolerance remains an intractable clinical obstacle for surgeons. Recently, traditional Chinese medicine has become a feasible alternative for certain diseases, including recurrent spontaneous abortion. However, because of the complex composition of the traditional Chinese medicine formula, its action mechanism remains unclear. Methods: We selected two isolated active ingredients (RAMP and baicalin) from the traditional Chinese medicine formula and used an abortion-prone CBA/J × DBA/2 model to simulate human RSA and compared the changes in fetal resorption rate, Treg cell percentage, and relevant cytokines before and after combination therapy. In addition, The mechanisms were preliminarily discussed using in vitro differentiation models. Results: In CBA/J × DBA/2 abortion-prone mice, the combination therapy resulted in a lower embryo resorption rate compared to that obtained with individual delivery of either RAMP or baicalin, thereby playing an embryo-protective role through the increase in Treg cells for the maintenance of maternal-fetal immune tolerance. In in vitro primary cell differentiation experiments, the concentration of Treg cells significantly increased from 11% to 17.9% after the combination therapy compared to that of the single administration group. Conclusion: the synergistic effects of RAMP and baicalin were responsible for Treg differentiation. The present study provides a solid basis for improving the applicability of traditional Chinese herbs in the treatment of recurrent spontaneous abortion. 展开更多
关键词 recurrent spontaneous abortion Atractylodes macrocephala Koidz. Scutellaria baicalensis Georgi CBA/J×DBA/2 regulatory T cells
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Spontaneous Paravesical and Broad Ligament Hematoma after Vaginal Delivery Had Uterine Artery Embolization after Evacuating the Hematoma
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作者 Aayat Jaaffar Naseeb Abrar Majdi Al Nasheet 《Open Journal of Obstetrics and Gynecology》 2024年第3期480-486,共7页
Broad ligament hematoma is typically seen during cesarean section due to rupture of branches of uterine and vaginal vessels and it’s rare to be seen post-normal vaginal delivery. Addressing puerperal hematomas postpa... Broad ligament hematoma is typically seen during cesarean section due to rupture of branches of uterine and vaginal vessels and it’s rare to be seen post-normal vaginal delivery. Addressing puerperal hematomas postpartum presents considerable challenges for obstetric care providers. While hematomas such as those affecting the vulva, vulvovaginal region, or paravaginal area are frequently encountered, retroperitoneal hematomas are rare and notably pose a greater risk to the life of the patient. The medical literature contains scant case reports on retroperitoneal hematomas, with no consensus on a definitive treatment approach. Pelvic arterial embolization has emerged as both a sensible and increasingly preferred method for treating these hematomas recently, but its application is contingent upon the patient maintaining hemodynamic stability and the availability of a specialized interventional embolization unit. In our case, we are presenting a very rare case of a 31-year-old primigravida female with a history of in vitro fertilization pregnancy. She delivered a normal vaginal delivery at 31 weeks gestation. Unfortunately, she experienced multiple complications intrapartum, including preeclampsia and placental abruption. These complications increased her risk of developing a broad ligament hematoma. 展开更多
关键词 Broad Ligament Paravesical Hematoma spontaneous Hematoma Uterine Artery Embolization Retroperitoneal Hematoma Vaginal Delivery
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Management of Spontaneous Intracerebral Haemorrhage (sICH) at the University Hospital of Brazzaville (CONGO)
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作者 Ekouele Mbaki Hugues Brieux Ngoma Niangui Léocia Exaucée +5 位作者 Diatewa Josué Euberma Boukaka Kala Rel Gerald Ngackosso Olivier Brice Mpandzou Ghislain Armel Boukassa Léon Ossou-Nguiet Paul Macaire 《Neuroscience & Medicine》 2024年第1期23-38,共16页
Spontaneous intracerebral haemorrhage (sICH) is characterised by bleeding within the brain parenchyma, without any accompanying vascular malformation, parenchymal abnormality or coagulation disorder. The study aimed t... Spontaneous intracerebral haemorrhage (sICH) is characterised by bleeding within the brain parenchyma, without any accompanying vascular malformation, parenchymal abnormality or coagulation disorder. The study aimed to depict the management of sICH at the University Hospital of Brazzaville (UHB). It was an observational, descriptive, and cross-sectional analysis. Data collection was conducted retrospectively, covering the period from January 1, 2020 to August 31, 2022, spanning two years and eight months. The study examined socio-demographic, diagnostic, therapeutic, and evolutionary variables. We included 274 cases. We observed 160 men (58.4%) and 114 women (41.6%), resulting in a sex ratio of 1.4. The mean age was 55.3 ± 11.4 years, with ages ranging from 31 to 93 years. The detection of sICH was typically a result of experiencing motor deficits (59.5%) or disorders of consciousness (37.2%). The weightiness of one half of the body was the most common reason for seeking medical advice. Hematoma was capsulo-lenticular in 159 cases (58%) and capsulo-thalamic in 63 cases (23%). Hematomas were <30 ml in 162 cases (59.1%) and >30 ml in 112 cases (40.9%), and associated with hydrocephalus in 11.7% of cases. Conservative medical treatment was administered in 257 cases (94.2%) while surgical treatment was performed in 16 cases (5.8%). The surgical techniques used were external ventricular drainage (EVD) in 2 cases, ventriculo-peritoneal shunt in 5 cases, and hematoma evacuation in 10 cases. Death occurred before the 7th day of hospitalisation in 73 cases (57.8%) and after in 46 cases (42.2%). The median time to death was four days (Q1 = 2 days;Q3 = 7 days), with extremes of 0 and 216 days. . 展开更多
关键词 spontaneous Intracerebral haemorrhage MANAGEMENT BRAZZAVILLE
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Time-shift effect of spontaneous combustion characteristics and microstructure difference of dry-soaked coal
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作者 Yikang Liu Haiyan Wang +4 位作者 Huiyong Niu Tao Wang Zhiwen Chen Yuqi Chen Qingjie Qi 《International Journal of Coal Science & Technology》 EI CAS CSCD 2023年第4期171-185,共15页
The physical and chemical properties of the air-dried residual coal after soaking in the goaf will change,resulting in an increase in its spontaneous combustion tendency.This study aimed to look into the features and ... The physical and chemical properties of the air-dried residual coal after soaking in the goaf will change,resulting in an increase in its spontaneous combustion tendency.This study aimed to look into the features and mechanism of soaked-dried coal's spontaneous combustion.Five samples of coal were dried to various degrees,and the weight loss features during thermal processing were examined.Based on this,the pore structure and chemical structure characteristics of the coal samples with the highest tendency to spontaneous combustion were quantitatively examined,and the mechanism by which soaking-drying afected the spontaneous combustion heating process of the remaining coal in goaf was investigated in turn.The results show that T1 decreases with the increase of drying time,T2–T6 shows a fuctuating change,and the ignition activation energy of 36-S-Coal is smaller than that of other coal samples.The pore type of 36-S-Coal changes from a oneend closed impermeable pore to an open pore,and the pore group area is large.During the 36 h drying process,the internal channels of the coal were dredged,and a large number of gravels and minerals were precipitated from the pores with the air fow.A large number of gravels were around the pores to form a surface structure that was easy to adsorb various gases.Furthermore,infrared spectroscopy was used to analyze the two coal samples.It was found that soaking and drying did not change the functional group types of coal samples,but the fatty chain degree of 36-S-Coal was reduced to 1.56.It shows that the aliphatic chain structure of coal is changed after 36 h of drying after 30 days of soaking,which leads to the continuous shedding of aliphatic chain branches of residual coal,and the skeleton of coal is looser,which makes the low-temperature oxidation reaction of 36-S-Coal easier.Based on the above results,the coal-oxygen composite mechanism of water-immerseddried coal is obtained,and it is considered that the key to the spontaneous combustion oxidation process of coal is to provide oxygen atoms and accelerate the formation of peroxides. 展开更多
关键词 Water-soaked coal Coal spontaneous combustion FTIR TG-DTG Pore structure Chemical structure parameters
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Injectable collagen scaffold with human umbilical cordderived mesenchymal stem cells promotes functional recovery in patients with spontaneous intracerebral hemorrhage:phase Ⅰ clinical trial
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作者 Xiao-Yin Li Wu-Sheng Deng +6 位作者 Zi-Qi Wang Zheng-Chao Li Shu-Lian Chen Zhen Song Quan Zhang Jin Liang Xu-Yi Chen 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第9期1999-2004,共6页
Animal expe riments have shown that injectable collagen scaffold with human umbilical cord-derived mesenchymal stem cells can promote recovery from spinal cord injury.To investigate whether injectable collagen scaffol... Animal expe riments have shown that injectable collagen scaffold with human umbilical cord-derived mesenchymal stem cells can promote recovery from spinal cord injury.To investigate whether injectable collagen scaffold with human umbilical cord-derived mesenchymal stem cells can be used to treat spontaneous intracerebral hemorrhage,this non-randomized phase I clinical trial recruited patients who met the inclusion criteria and did not meet the exclusion crite ria of spontaneous intracerebral hemorrhage treated in the Characteristic Medical Center of Chinese People’s Armed Police Force from May 2016 to December 2020.Patients were divided into three groups according to the clinical situation and patient benefit:control(n=18),human umbilical cord-derived mesenchymal stem cells(n=4),and combination(n=8).The control group did not receive any transplantation.The human umbilical cord-derived mesenchymal stem cells group received human umbilical cord-derived mesenchymal stem cell transplantation.The combination group received injectable collagen scaffold with human umbilical cord-derived mesenchymal stem cells.Patients who received injectable collagen scaffold with human umbilical cord-derived mesenchymal stem cells had more remarkable improvements in activities of daily living and cognitive function and smaller foci of intra cerebral hemorrhage-related encephalomalacia.Severe adve rse events associated with cell transplantation were not observed.Injectable collagen scaffold with human umbilical cord-derived mesenchymal stem cells appears to have great potential treating spontaneous intracerebral hemorrhage. 展开更多
关键词 clinical trial collagen scaffold efficacy human umbilical cord-derived mesenchymal stem cells human SAFE neurological recovery spontaneous intracerebral hemorrhage TRANSPLANTATION
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Quantitative characterization of shale pore connectivity and controlling factors using spontaneous imbibition combined with nuclear magnetic resonance T_(2)and T_(1)-T_(2)
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作者 Peng-Fei Zhang Shuang-Fang Lu +7 位作者 Jun-Qian Li Xiang-Chun Chang Jun-Jian Zhang Yu-Mao Pang Zi-Zhi Lin Guo Chen Ya-Jie Yin Yu-Qi Liu 《Petroleum Science》 SCIE EI CAS CSCD 2023年第4期1947-1960,共14页
Shale oil can be extracted from shale by using interconnected pore networks.The migration of hydrocarbon molecules within the shale is controlled by pore connectivity.However,assessing the pore connectivity of shale o... Shale oil can be extracted from shale by using interconnected pore networks.The migration of hydrocarbon molecules within the shale is controlled by pore connectivity.However,assessing the pore connectivity of shale oil reservoirs is uncommon.To characterize pore connectivity and clarify its controlling factors,this study used spontaneous imbibition(SI)combined with nuclear magnetic resonance(NMR)T_(2)and T_(1)-T_(2)technologies on shale oil reservoirs selected from the Shahejie Formation in the Dongying Sag,Bohai Bay Basin.According to the findings,the SI processes of shales include fast-rising,slow-rising,and stable stages.The fast-rising stage denotes pore connectivity.The shales studied have poor connectivity,with lower imbibition slopes and connected porosity ratios,but large effective tortuosity.During the SI process,micropores have the highest imbibition saturation,followed by mesopores and macropores.Furthermore,n-dodecane ingested into micropores appears primarily as adsorbed,whereas n-dodecane appears primarily as free states in mesopores and macropores during the SI process.The pore connectivity of the shales under study is primarily controlled by inorganic minerals.Quartz and feldspar develop large and regular pores,resulting in better pore connectivity,whereas clay minerals and calcite with plenty of complex intragranular pores do not.Organic matter negatively influences pore connectivity because the dissolution of calcite by organic acid produced during hydrocarbon generation leads to a more complex and heterogeneous pore structure.This study sheds light on the pore connectivity and controlling factors of the shale oil reservoir and aids in the understanding of shale oil mobility. 展开更多
关键词 Pore connectivity spontaneous imbibition Nuclear magnetic resonance Mercury intrusion capillary pressure Shale oil reservoir
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Spontaneous emission fromΛ-type three-level atom driven by bichromatic field in anisotropic double-band photonic crystals
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作者 凌凯 姜丽 +1 位作者 万仁刚 姚治海 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第4期389-396,共8页
The spontaneous emission property ofΛ-type three-level atom driven by the bichromatic field in the anisotropic double-band photonic crystal is calculated by n-times iteration method.The influence of different paramet... The spontaneous emission property ofΛ-type three-level atom driven by the bichromatic field in the anisotropic double-band photonic crystal is calculated by n-times iteration method.The influence of different parameters on atomic spontaneous emission is studied,and the phenomena of atomic spontaneous emission are explained in the dressed state representation.It is found that the spontaneous emission spectra of the atom driven by the bichromatic field presents a multi-peak comb structure.The position of the emission peak is determined by the initial state of the atom,and the interval between the neighboring emission peaks is the detuningδof the bichromatic field.When the ratio between Rabi frequency intensity and the detuningδof the bichromatic field remains unchanged,the intensity of each emitted peak remains invariant.The spontaneously emitted peak can be annihilated in the band gap and enhanced near the band edge in the anisotropic photonic crystals.Meanwhile,we also observe the fluorescence quenching phenomenon in the spontaneous emission spectra.The research in this paper provides the theoretical guidance for the control of atomic spontaneous emission. 展开更多
关键词 photonic crystal bichromatic field spontaneous emission spectra dressed state
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Spontaneous fracture of a titanium mesh cranioplasty implant in a child: A case report
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作者 Rui Zhang Zhe Gao +3 位作者 Yong-Jie Zhu Xin-Fa Wang Gang Wang Jun-Ping He 《World Journal of Clinical Cases》 SCIE 2023年第7期1593-1599,共7页
BACKGROUND Titanium mesh cranioplasty is often performed after decompressive craniectomy.Spontaneous fracture of the titanium prosthesis is an extremely rare postoperative complication.Here,we report a 10-year-old boy... BACKGROUND Titanium mesh cranioplasty is often performed after decompressive craniectomy.Spontaneous fracture of the titanium prosthesis is an extremely rare postoperative complication.Here,we report a 10-year-old boy who presented with a spontaneous fracture of titanium mesh without antecedent head trauma.CASE SUMMARY A 10-year-old boy presented with a 1-wk history of a tender bulge over the left temporo-parieto-occipital scalp.He had undergone a temporo-parieto-occipital titanium mesh cranioplasty 26 mo previously.He denied antecedent head trauma.Computerized tomography disclosed a perpendicular fissure in the titanium mesh,suggesting a diagnosis of spontaneous titanium mesh fracture.He underwent a second temporo-parieto-occipital cranioplasty and made an uneventful recovery.Three-dimensional modeling and finite element analyses were used to explore potential risk factors of titanium mesh fracture.CONCLUSION We report a case of spontaneous fracture of a titanium mesh cranioplasty implant.The current case and literature review indicate that titanium mesh implants should be well-anchored to the base of bony defects to prevent fatigue-induced fractures. 展开更多
关键词 CRANIOPLASTY Prosthesis fracture spontaneous fracture Titanium Case report
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Impact of amplified spontaneous emission noise on the SRS threshold of high-power fiber amplifiers
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作者 刘伟 任帅 +1 位作者 马鹏飞 周朴 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第3期234-238,共5页
Impact of amplified spontaneous emission(ASE)noise on the stimulated Raman scattering(SRS)threshold of highpower fiber amplifiers is demonstrated numerically through a spectral evolution approach.The simulation result... Impact of amplified spontaneous emission(ASE)noise on the stimulated Raman scattering(SRS)threshold of highpower fiber amplifiers is demonstrated numerically through a spectral evolution approach.The simulation results confirm that ASE noise in the Raman wavelength band could reduce the SRS threshold of high-power fiber amplifiers significantly.As for ASE noise originated the main amplifier,it becomes stronger and reduces the SRS threshold at shorter operation wavelength below 1052 nm.As for ASE noise originated from the seed laser,it reduces the SRS threshold at different operation wavelength under the condition that the Raman ratio is over-90 dB in the seed laser.The theoretical method and results in this work could provide a well reference to extend the operation wavelength of high-power fiber lasers. 展开更多
关键词 high-power fiber amplifiers amplified spontaneous emission stimulated Raman scattering
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Spontaneous emission of a moving atom in a waveguide of rectangular cross section
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作者 曾静 卢竞 周兰 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第2期92-96,共5页
We study the spontaneous emission(SE) of an excited nonrelativistic two-level system(TLS) interacting with the vacuum in a waveguide of rectangular cross section. All TLS’s transitions and the center-of-mass motion o... We study the spontaneous emission(SE) of an excited nonrelativistic two-level system(TLS) interacting with the vacuum in a waveguide of rectangular cross section. All TLS’s transitions and the center-of-mass motion of the TLS are taken into account. The SE rate and the carried frequency of the emitted photon for the TLS initially being at rest are obtained, it is found that in the first order of the mass M, the frequency of the emitted photon is smaller than the transition frequency of the TLS and the SE rate is smaller than the SE rate Γfof the TLS fixed in the same waveguide. The SE rate for the TLS initially being moving is obtained in the second order of the mass M. The SE rate is smaller than Γfbut it is dependent not only on the atomic mass but also on the initial momentum. The carried frequency of the emitted photon is decreased when it travels along the direction of the initial momentum, whereas it is increased when it travels in the opposite direction of the initial momentum. 展开更多
关键词 spontaneous emission moving atom waveguide of rectangular cross section
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Spontaneous gastric hematoma as a rare cause of acute abdomen:A case report
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作者 Ivan Budimir MirnaŽulec +2 位作者 Ksenija Eljuga MarcelŽidak Valentino Lisek 《World Journal of Clinical Cases》 SCIE 2023年第36期8551-8556,共6页
BACKGROUND Spontaneous gastric hematoma is an exceedingly rare condition characterized by the accumulation of blood within the gastric wall without any apparent iatrogenic or traumatic cause.Coagulopathies are the mos... BACKGROUND Spontaneous gastric hematoma is an exceedingly rare condition characterized by the accumulation of blood within the gastric wall without any apparent iatrogenic or traumatic cause.Coagulopathies are the most frequent cause of gastric he-matomas.However,other causes include amyloidosis,pancreatitis,visceral vas-cular aneurysms,endoscopy complications and others.The pathophysiology of spontaneous gastric hematoma is not completely understood.However,it is postulated that it is caused by disruption of submucosal vessels that leads to dissection of the muscularis layer and formation of false lumen.The rarity of this condition increases the challenge of diagnosis,and there is no standard treatment protocol.CASE SUMMARY We present the case of a spontaneous gastric hematoma in a 22-year-old male.He presented to our emergency department complaining of pain in the left flank area lasting for 2 wk.There was no history of trauma,antico-agulant medications or endoscopy procedures.His hemoglobin and hematocrit levels were slightly lower than normal.Multi-slice computed tomography,ultrasound and endoscopy confirmed a gastric intramural hematoma.We recommended conservative treatment because there was no hemodynamic instability nor significant bleeding.The patient responded well,and there were no unexpected events.At the 3-mo follow-up,the ultrasound exa-mination revealed complete regression of the hematoma.CONCLUSION After reviewing the literature and our experience,we recommend that more of these cases should be treated conservatively.The tendency to treat these cases with potentially burdensome procedures such as total or subtotal gastrectomy should be significantly reduced. 展开更多
关键词 spontaneous Intramural hematoma STOMACH Acute abdomen Conservative treatment Case report
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Spontaneous Heparin-Induced Thrombocytopenia Presenting as Concomitant Bilateral Cerebrovascular Infarction and Acute Coronary Syndrome
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作者 Jong Kun Park Ilan Vavilin +4 位作者 Jacob Zaemes Araba Ofosu-Somuah Raghav Gattani Camila Sahebi Alexander G.Truesdell 《Cardiovascular Innovations and Applications》 2023年第1期44-48,共5页
Background:Spontaneous heparin-induced thrombocytopenia is a pro-thrombotic syndrome in which anti-heparin antibodies develop without heparin exposure.Case presentation:A 78-year-old man who underwent a successful lum... Background:Spontaneous heparin-induced thrombocytopenia is a pro-thrombotic syndrome in which anti-heparin antibodies develop without heparin exposure.Case presentation:A 78-year-old man who underwent a successful lumbar laminectomy presented to the hospital 5 days after discharge for stroke-like symptoms and was found to have acute infarcts of the bilateral frontal lobes.The patient was found to be severely thrombocytopenic and was incidentally found to have an inferior wall myocardial infarction.Further investigation led to the diagnosis of bilateral lower extremity deep vein thromboses.His overall clinical presentation prompted a detailed hematologic workup that indicated positivity for heparin-induced thrombocy-topenia despite no previous exposure to heparin products.Conclusions:This case illustrates a patient with no prior lifetime heparin exposure who underwent laminectomy with subsequent development of acute infarcts of the bilateral frontal lobes,an inferior wall myocardial infarction,and bilateral lower extremity deep vein thromboses,with concern for sequelae of spontaneous heparin-induced thrombo-cytopenia. 展开更多
关键词 Acute coronary syndrome deep vein thrombosis myocardial infarction cerebrovascular infarction spontaneous heparin-induced thrombocytopenia
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Spontaneous coronary artery dissection-associated takotsubo syndrome: A systematic review of case reports
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作者 Aditi Bhanushali Muskan Kohli +8 位作者 Ananya Prakash Svaapnika Rao Sarvepalli Anchal Pandey Olufemi Odugbemi Nafisa Reyaz Bansi Trambadia Sadhu Aishwarya Reddy Shaylika Chauhan Rupak Desai 《World Journal of Cardiology》 2023年第8期406-414,共9页
BACKGROUND Spontaneous coronary artery dissection(SCAD)is underdiagnosed and requires comprehensive angiographic findings.Few SCAD occurrences have a comparable clinical appearance as takotsubo syndrome(TTS)or exist s... BACKGROUND Spontaneous coronary artery dissection(SCAD)is underdiagnosed and requires comprehensive angiographic findings.Few SCAD occurrences have a comparable clinical appearance as takotsubo syndrome(TTS)or exist simultaneously,making it challenging for clinicians to treat and manage.Case reports lack consolidated AIM To conduct a systematic review of available case reports on SCAD in order to investigate its potential association with TTS.METHODS SCAD-associated TTS case reports were reviewed after thoroughly screening PubMed,EMBASE,Scopus,and Google Scholar databases till January 2023.Case reports described demographics,comorbidities,imaging,management,and results.RESULTS Twelve articles about 20 female patients were analyzed.30%of patients(n=6,>60 years)were elderly(mean age 56.2±9.07 years,range 36-70 years).Canada has 9 cases,United States 3,Australia 3,Sweden 2,Japan,Denmark,and France 1.Only 5 reports identified emotional stressors in these cases while 4 reports showed physical triggers for TTS.Nine had hypertension,2 had hyperlipidemia,and 1 had prediabetes.5 patients(25%)smoked.10(50%)troponin-positive myocardial infarction patients reported chest discomfort.11(55%)of 20 instances had TTS/SCAD.12(60%)of 20 patients exhibited ST elevation and 3(15%)had T wave inversion on electrocardiogram.19/20 patients had elevated troponin.9(45%)of 20 people had apical akinesis with TTS ballooning on cardiac imaging.All 20 exhibited echocardiographic wall motion abnormalities.19(95%)of 20 coronary angiography cases had SCAD.10 of 19 SCAD patients had left anterior descending,2 diagonal,and 2 left circumflex coronary artery involvement.7 of 20 patients had left ventricular ejection fraction(LVEF)data.LVEF averaged 38.78±7.35%.5(25%)of the 20 cases underwent dual antiplatelet therapy.Three(15%)of 20 cases experienced occasional ectopic ventricular complexes,Mobitz ll AV block,and paroxysmal atrial fibrillation.All 20 cases recovered and survived.CONCLUSION Given the clinical similarities and challenges in detecting TTS and SCAD,this subset needs more research to raise awareness and reduce morbidity. 展开更多
关键词 spontaneous coronary artery dissection Takotsubo syndrome Takotsubo cardiomyopathy Systematic review Coronary angiography CARDIOLOGY
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