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Apically guiding electron/mass transfer reaction induced by Ag/FeN_(x)Mott-Schottky effect within a hollow star reactor toward high performance zinc-air batteries
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作者 Kaixiang Shi Kaixin Wang +7 位作者 Tong Li Junhao Li Jie Ren Xu Li Yonggang Min Zhouguang Lu Wei Tan Quanbing Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期106-116,I0004,共12页
The disparity in the transfer of carriers(electrons/mass)during the reaction in zinc-air batteries(ZABs)results in sluggish kinetics of the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),along with e... The disparity in the transfer of carriers(electrons/mass)during the reaction in zinc-air batteries(ZABs)results in sluggish kinetics of the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),along with elevated overpotentials,thereby imposing additional constraints on its utilization.Therefore,the pre-design and target-development of inexpensive,high-performance,and long-term stable bifunctional catalysts are urgently needed.In this work,an apically guiding dual-functional electrocatalyst(Ag-FeN_(x)-N-C)was prepared,in which a hierarchical porous nitrogen-doped carbon with three-dimensional(3D)hollow star-shaped structure is used as a substrate and high-conductivity Ag nanoparticles are coupled with iron nitride(FeN_(x))nanoparticles.Theoretical calculations indicate that the Mott-Schottky heterojunction as an inherent electric field comes from the two-phase bound of Ag and FeN_(x),of which electron accumulation in the FeN_(x)phase region and electron depletion in the Ag phase region promote orientated-guiding charge migration.The effective modulation of local electronic structures felicitously reforms the d-band electron-group distribution,and intellectually tunes the masstransfer reaction energy barriers for both ORR/OER.Additionally,the hollow star-s haped hierarchical porous structure provides an apical region for fast mass transfer.Experimental results show that the halfwave potential for ORR is 0.914 V,and the overpotential for OER is only 327 mV at 10 mA cm^(-2).A rechargeable ZAB with Ag-FeN_(x)-N-C as the air cathode demonstrates long-term cycling performance exceeding 1500 cycles(500 h),with a power density of 180 mW cm^(-2).Moreover,when employing AgFeN_(x)-N-C as the air cathode,flexible ZABs demonstrate a notable open-circuit voltage of 1.42 V and achieve a maximum power density of 65.6 mW cm^(-2).Ag-FeN_(x)-N-C shows guiding electron/mass transfer route and apical reaction microenvironment for the electrocatalyst architecture in the exploration prospects of ZABs. 展开更多
关键词 Hollow star structure Mott-Schottky effect apically guiding effect Bifunctional catalysis Zinc-air batteries
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Microsurgical management of radicular cyst using guided tissue regeneration technique:A case report
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作者 Juan Carlos Gómez Mireles Eugenia Karina Martínez Carrillo +5 位作者 Katia Alcalá Barbosa Evangelina Gutiérrez Cortés Javier González Ramos Luis Antonio González Gómez Rubén Alberto Bayardo González Sarah Monserrat Lomelí Martínez 《World Journal of Clinical Cases》 SCIE 2024年第7期1346-1355,共10页
BACKGROUND Radicular cyst is a lesion of odontogenic origin that arises from epithelial remains due to periapical periodontitis caused by inflammatory reactions generated at the apex of affected teeth with infected or... BACKGROUND Radicular cyst is a lesion of odontogenic origin that arises from epithelial remains due to periapical periodontitis caused by inflammatory reactions generated at the apex of affected teeth with infected or necrotic pulps.The therapeutic mana gement of radicular cysts is controversial.There is only one case report of enucleation of a radicular cyst managed with microsurgery and apicoectomy,but without the use of the guided tissue regeneration(GTR)technique in the same surgical procedure.The present clinical case describes the management of a radicular cyst with microsurgical approach,performance of an apicoectomy of the tooth associated with the entity,application of GTR technique,use of a resorbable membrane of type I bovine collagen,and bovine xenograft.CASE SUMMARY A 68-year-old patient presented with a radicular cyst from an upper lateral incisor.The microsurgical management used was aimed at enucleating the chemical membrane,performing apicoectomy of the tooth along with careful and precise retrograde filling,and implementing GTR technique using a resorbable collagen membrane and bovine xenograft.The diagnosis of radicular cyst was confirmed using histopathological analysis.The patient underwent follow-up evaluations at 10 and 30 d postoperatively.At 4 months postoperative evaluation,she remained asymptomatic,and radiographs showed significant periapical healing with adequate bone formation.CONCLUSION These results suggest that microsurgical management using the GTR technique with collagen membrane and xenograft,contributes to bone regeneration. 展开更多
关键词 Odontogenic cysts Apical periodontal cyst Dental root end cyst Case report
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Evaluation of the Effectiveness and Safety of One-Time Endodontics in the Treatment of Chronic Apical Periodontitis with Sinus Tract in Pediatric Deciduous Teeth
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作者 Yi Liu 《Journal of Clinical and Nursing Research》 2024年第6期111-116,共6页
Objective:To observe the effectiveness and safety of one-time endodontics in the treatment of chronic apical periodontitis with sinus tract in pediatric deciduous teeth.Methods:109 cases of children with chronic apica... Objective:To observe the effectiveness and safety of one-time endodontics in the treatment of chronic apical periodontitis with sinus tract in pediatric deciduous teeth.Methods:109 cases of children with chronic apical periodontitis with sinus tract in the deciduous teeth treated in our hospital from January 2022 to December 2023 were selected and grouped by the randomized numerical table method,with 54 cases in the experimental group and 55 cases in the control group.The experimental group was treated with one-time endodontics and the control group was treated with conventional endodontics.Results:After the treatment,the total effective rate of treatment was higher in the experimental group than in the control group(P<0.05);the incidence of adverse events was lower in the experimental group than in the control group(P<0.05);the satisfaction of the children's family members was higher in the experimental group than in the control group(P<0.05);the pain duration was lower in the experimental group than in the control group(P<0.05).Conclusion:In the experimental group,children with chronic apical periodontitis with sinus tract of the deciduous teeth were given one-time endodontic treatment,and the results of its implementation were relatively good. 展开更多
关键词 One-time endodontics Chronic apical periodontitis with sinus tract Pediatric deciduous teeth Therapeutic effectiveness SAFETY
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Predicting apical hypertrophic cardiomyopathy using T-wave inversion:Three case reports 被引量:1
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作者 Liang Kang Yi-Hua Li +1 位作者 Rong Li Qing-Min Chu 《World Journal of Clinical Cases》 SCIE 2023年第25期5970-5976,共7页
BACKGROUND Apical hypertrophic cardiomyopathy(AHCM)is a subtype of hypertrophic cardiomyopathy.Due to its location,the thickening of the left ventricular apex can be missed on echocardiography.Giant negative T waves(G... BACKGROUND Apical hypertrophic cardiomyopathy(AHCM)is a subtype of hypertrophic cardiomyopathy.Due to its location,the thickening of the left ventricular apex can be missed on echocardiography.Giant negative T waves(GNTs)in left-sided chest leads are the hallmark electrocardiogram(ECG)change of AHCM.CASE SUMMARY The first patient was a 68-year-old woman complaining of recurrent chest tightness persisting for more than 3 years.The second was a 59-year-old man complaining of spasmodic chest tightness persisting for more than 2 years.The third was a 55-year-old woman complaining of recurrent chest pain persisting for 4 mo.In all three cases,GNTs were observed several years prior to apical cardiac hypertrophy after other causes of T-wave inversion were ruled out.CONCLUSION Electrophysiological abnormalities of AHCM appear earlier than structural abnormalities,confirming the early predictive value of ECG for AHCM. 展开更多
关键词 ELECTROCARDIOGRAM Negative T waves Hypertrophic cardiomyopathy Apical hypertrophic cardiomyopathy ECHOCARDIOGRAPHY Case report
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Isolated left ventricular apical hypoplasia:Systematic review and analysis of the 37 cases reported so far 被引量:1
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作者 Pier Paolo Bassareo Sophie Duignan +3 位作者 Adam James Esme Dunne Colin J McMahon Kevin P Walsh 《World Journal of Clinical Cases》 SCIE 2023年第23期5494-5503,共10页
BACKGROUND Isolated left ventricular apical hypoplasia(ILVAH),also known as truncated left ventricle(LV),is a very unusual cardiomyopathy.It is characterised by a truncated,spherical,and non-apex forming LV.The true a... BACKGROUND Isolated left ventricular apical hypoplasia(ILVAH),also known as truncated left ventricle(LV),is a very unusual cardiomyopathy.It is characterised by a truncated,spherical,and non-apex forming LV.The true apex is occupied by the right ventricle.Due to the rarity of the disease,just a few case reports and limited case series have been published in the field.AIM To analysing the so far 37 reported ILVAH cases worldwide.METHODS The electronic databases PubMed and Scopus were investigated from their establishment up to December 13,2022.RESULTS The majority of cases reported occurred in males(52.7%).Mean age at diagnosis was 26.1±19.6 years.More than a third of the patients were asymptomatic(35.1%).The most usual clinical presentation was breathlessness(40.5%).The most commonly detected electrocardiogram changes were T wave abnormalities(29.7%)and right axis deviation with poor R wave progression(24.3%).Atrial fibrillation/flutter was detected in 24.3%.Echocardiography was performed in 97.3%of cases and cardiac MRI in 91.9%of cases.Ejection fraction was reduced in more than a half of patients(56.7%).An associated congenital heart disease was found in 16.2%.Heart failure therapy was administered in 35.1%of patients.The outcome was favorable in the vast majority of patients,with just one death.CONCLUSION ILVAH is a multifaceted entity with a so far unpredictable course,ranging from benign until the elderly to sudden death during adolescence. 展开更多
关键词 Isolated left ventricular apical hypoplasia Truncated left ventricle ELECTROCARDIOGRAPHY ECHOCARDIOGRAPHY Cardiac magnetic resonance imaging Heart failure
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Role of preoperative magnetic resonance imaging on the surgical outcomes of radical prostatectomy:Does preoperative tumor recognition reduce the positive surgical margin in a specific location?Experience from a Thailand prostate cancer specialized center
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作者 Thitipat Hansomwong Pat Saksirisampant +6 位作者 Sudhir Isharwal Pubordee Aussavavirojekul Varat Woranisarakul Siros Jitpraphai Sunai Leewansangtong Tawatchai Taweemonkongsap Sittiporn Srinualnad 《Asian Journal of Urology》 CSCD 2023年第4期494-501,共8页
Objective Multiparametric magnetic resonance imaging(MRI)has become the standard of care for the diagnosis of prostate cancer patients.This study aimed to evaluate the influence of preoperative MRI on the positive sur... Objective Multiparametric magnetic resonance imaging(MRI)has become the standard of care for the diagnosis of prostate cancer patients.This study aimed to evaluate the influence of preoperative MRI on the positive surgical margin(PSM)rates.Methods We retrospectively reviewed 1070 prostate cancer patients treated with radical prostatectomy(RP)at Siriraj Hospital between January 2013 and September 2019.PSM rates were compared between those with and without preoperative MRI.PSM locations were analyzed.Results In total,322(30.1%)patients underwent MRI before RP.PSM most frequently occurred at the apex(33.2%),followed by posterior(13.5%),bladder neck(12.7%),anterior(10.7%),posterolateral(9.9%),and lateral(2.3%)positions.In preoperative MRI,PSM was significantly lowered at the posterior surface(9.0%vs.15.4%,p=0.01)and in the subgroup of urologists with less than 100 RP experiences(32%vs.51%,odds ratio=0.51,p<0.05).Blood loss was also significantly decreased when a preoperative image was obtained(200 mL vs.250 mL,p=0.02).Multivariate analysis revealed that only preoperative MRI status was associated with overall PSM and PSM at the prostatic apex.Neither the surgical approach,the neurovascular bundle sparing technique,nor the perioperative blood loss was associated with PSM.Conclusion MRI is associated with less overall PSM,PSM at apex,and blood loss during RP.Additionally,preoperative MRI has shown promise in lowering the PSM rate among urologists who are in the early stages of performing RP. 展开更多
关键词 Preoperative magnetic resonance imaging Prostate cancer Positive surgical margin Radical prostatectomy APEX Apical positive surgical margin
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Different endodontic treatments induced root development of two nonvital immature teeth in the same patient:A case report
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作者 Rong Chai Xiu Yang An-Sheng Zhang 《World Journal of Clinical Cases》 SCIE 2023年第11期2567-2575,共9页
BACKGROUND Pulp revascularization is a novel way to treat immature teeth with periapical disease,and the technique has become increasingly well established in recent years.By puncturing the periapical tissue,bleeding ... BACKGROUND Pulp revascularization is a novel way to treat immature teeth with periapical disease,and the technique has become increasingly well established in recent years.By puncturing the periapical tissue,bleeding is induced,and a blood clot is formed in the root canal.The blood clot acts as a natural bioscaffold onto which mesenchymal stem cells from periapical tissue can be seeded and restore pulp vascularity,thus promoting root development as well as apical closure.Although the effect of pulp revascularization is ideal,there are certain requirements for the apical condition of the teeth.The apical barrier technique and apexification are still indispensable for teeth that cannot achieve ideal blood clot formation.In addition,a meta-analysis of several clinical studies concluded that pulp revascu-larization has no significant advantages over other treatments.CASE SUMMARY A 10-year-old girl complained of pain in the right upper and lower posterior teeth for 2 d.Clinical and radiological examinations revealed that both the right maxillary and mandibular second premolars were immature with periapical radiolucency.The right maxillary second premolar was treated by pulp revascu-larization,while the right mandibular second premolar was treated by conven-tional apical barrier surgery after revascularization failed.The purpose of this report is to compare the different root maturation processes induced by the pulp revascularization and apical barrier techniques in the same patient in homonymous teeth from different jaws.Twelve months of follow-up showed that the apical foramen of both teeth presented a clear tendency to close;however,the tooth treated with pulp revascularization showed a significant increase in root length as well as root canal wall thickness.CONCLUSION For the treatment of nonvital immature teeth,pulp revascularization showed a superior therapeutic effect in comparison with the apical barrier technique. 展开更多
关键词 Nonvital immature tooth Central cusp deformity Pulp revascularization Apical barrier technique Root canal Case report
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Application of apical negative pressure irrigation in the nonsurgical treatment of radicular cysts:A case report
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作者 Gong-Pei Chen Yan-Zhen Zhang Dan-Hua Ling 《World Journal of Clinical Cases》 SCIE 2023年第15期3612-3618,共7页
BACKGROUND Radicular cysts are one of the most common odontogenic cystic lesions found in the jaw.Nonsurgical treatment of large radicular cysts is a topic of ongoing debate,and there is still no clear consensus on th... BACKGROUND Radicular cysts are one of the most common odontogenic cystic lesions found in the jaw.Nonsurgical treatment of large radicular cysts is a topic of ongoing debate,and there is still no clear consensus on the most effective therapies.The apical negative pressure irrigation system aspirates the cystic fluid and releases the static pressure in the radicular cyst,representing a minimally invasive approach for decompression.In this case,the radicular cyst was in close proximity to the mandibular nerve canal.We used nonsurgical endodontic treatment with a homemade apical negative pressure irrigation system and the prognosis was good.CASE SUMMARY A 27-year-old male presented to our Department of General Dentistry with complaints of pain in the mandibular right molar when chewing.The patient had no history of drug allergies or systemic disease.A multidisciplinary management approach was designed and included root canal retreatment with a homemade apical negative pressure irrigation system,deep margin elevation and prosthodontic treatment.According to a 1-year follow-up period,the patient showed a favorable outcome.CONCLUSION This report reveals that nonsurgical treatment with an apical negative pressure irrigation system may provide new insights into the treatment of radicular cysts. 展开更多
关键词 Apical negative pressure irrigation Radicular cyst Nonsurgical root canal treatment Case report
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Five-year outcomes of immediate implant placement for mandibular molars with and without chronic apical periodontitis:A retrospective study
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作者 Hua Yang Dan Luo +2 位作者 Mu-Jie Yuan Jian-Jun Yang Da-Shan Wang 《World Journal of Clinical Cases》 SCIE 2023年第22期5224-5235,共12页
BACKGROUND Most physicians consider molars with chronic apical periodontitis(CAP)lesions as contraindications for immediate implant placement.At the patient’s request,we perform immediate implant placement of the man... BACKGROUND Most physicians consider molars with chronic apical periodontitis(CAP)lesions as contraindications for immediate implant placement.At the patient’s request,we perform immediate implant placement of the mandibular molars with CAP in clinical practice.AIM To retrospectively analyze and compare the 5-year outcomes of immediate implant placement of the mandibular molars with CAP and those without obvious inflammation.METHODS The clinical data of patients with immediate implant placement of the mandibular molars in the Department of Oral and Maxillofacial Surgery,the Affiliated Hospital of Qingdao University,from June 2015 to June 2017 were collected.The patients were divided into CAP(n=52)and no-CAP(n=45)groups.Changes in bone mineral density and bone mass around implants were analyzed 5 years after implant restoration.RESULTS At 5 years after implantation,the peri-implant bone mineral density was 528.2±78.8 Hounsfield unit(HU)in the CAP group and 562.6±82.9 HU in the no-CAP group(P=0.126).Marginal bone resorption around implants did not differ significantly between the two groups,including buccal(P=0.268)or lingual(P=0.526)resorption in the vertical direction or buccal(P=0.428)or lingual(P=0.560)resorption in the horizontal direction.Changes in the peri-implant jump space did not differ significantly between the two groups,including the buccal(P=0.247)or lingual(P=0.604)space in the vertical direction or buccal(P=0.527)or lingual(P=0.707)space in the horizontal direction.The gray value of cone-beam computed tomography measured using Image J software can reflect the bone mineral density.In the CAP area,the gray values of the bone tissue immediately and 5 years after implant placement differed significantly from those of the surrounding bone tissue(P<0.01).CONCLUSION The results of this study suggest that immediate implant placement of the mandibular molars with CAP can achieve satisfactory 5-year clinical results,without significant differences in the complications,survival rate,or bone tissue condition from the no-CAP mandibular molars. 展开更多
关键词 MOLAR Chronic apical periodontitis Dental implantation Bone density Treatment outcome Retrospective study
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Accuracy of screw placement in the apical region of Lenke 1 adolescent idiopathic scoliosis surgery using a calibration technique for the intraoperative navigation error
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作者 CHEN Huan-xiong HE Xian-bo +6 位作者 LI Guo-jun TANG Song-jie ZHONG Zhen-hao HUANG Tao LIN You-cai LIN Su-yu MENG Zhi-bin 《Journal of Hainan Medical University》 CAS 2023年第6期43-50,共8页
Objective:To study the position and the grade of screw perforation in the apical region of adolescent idiopathic scoliosis(AIS)surgery using a calibration technique for the intraoperative navigation error,and to analy... Objective:To study the position and the grade of screw perforation in the apical region of adolescent idiopathic scoliosis(AIS)surgery using a calibration technique for the intraoperative navigation error,and to analyze the related factors of navigation deviation and the clinical significance of the calibration technique.Methods:From 2017 to 2020,a total of 60 Lenke 1 AIS surgical cases were enrolled in this research.The 30 cases received surgery using the intraoperative navigation system(Navigation group)and another 30 cases were assisted with intraoperative navigation system with calibration technique(Calibration group)for the intraoperative navigation error.The basic information and radiological data of the both groups were all recorded.According to the Fu Chang-feng’s pedicle channel classification system,the pedicle on the apical region of the two groups was classified.And then the accuracy of screw placement of the two groups was evaluated according to the Rao’s classification.Results:A total of 600 screws were placed in the two groups.The 297 and 303 pedicle screws were implanted in the navigation group and the calibration group,respectively.In the apical region of the calibration group,the rates of the grade 0 screw placement in type A,B and C pedicle were 95.7%,86.7%and 68.9%respectively.It was a statistically significant difference from the 73.9%,66.9%and 30.0%in the navigation group respectively(P<0.05).In the calibration group,the rates of the medial cortical perforation in the type A,B,C and D pedicle were 0%,1.6%,1.6%and 0%,respectively.The corresponding rates were 16.3%,16.9%,30.0%and 47.6%in the navigation group,respectively.Moreover,in the concave side of the apical region of the calibration group,the rates of the medial cortical perforation in the type A,B,C and D pedicle were 0%,3.6%,2.6%and 0%,respectively.Compared with the calibration group,the corresponding rates were higher in the navigation group(34.4%,25.9%,37.2%and 60.0%,respectively).No serious complications such as spinal cord or neurovascular injury occurred for the two groups.Conclusion:Compared with the intraoperative navigation system,the calibration technique for the intraoperative navigation error could provide the higher accuracy of pedicle screw placement in the apical region of the major curve,the lower medial cortical perforation rate,the less screws misplacement rate on the concave side and the less complication rate of the severe Lenke 1 AIS patients. 展开更多
关键词 Adolescent idiopathic scoliosis Apical region Pedicle channel classification Pedicle screw Navigation error
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Root Resorption in Anterior Open Bite Malocclusions Due to Vertical Correction: A Radiometric Pilot Study
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作者 Suhina Kapoor David Briss +1 位作者 Shuying Jiang Thomas J. Cangialosi 《Open Journal of Orthopedics》 2023年第6期233-245,共13页
Introduction: One of the most common risks of fixed orthodontic therapy is the evidence of root resorption post orthodontic treatment ranging from mild root blunting to severe root resorption of significant portions o... Introduction: One of the most common risks of fixed orthodontic therapy is the evidence of root resorption post orthodontic treatment ranging from mild root blunting to severe root resorption of significant portions of the root structure. The etiology of apical root resorption is multifactorial but largely depends upon the type of orthodontic tooth movement and treatment duration. Study Objective: The primary aim of this study is to examine the association of external apical root resorption and vertical correction in anterior open bite malocclusions using panoramic radiographs for evaluation. Materials and Methods: Pre-treatment and post-treatment panoramic radiographs of 16 patients with anterior open bite malocclusions were scored to assess root resorption of anterior teeth (U/L 3-3). Initial and final root length and total tooth length for U/L 3-3 were measured on panoramic radiographs in Dolphin imaging. Results: Of the 24 pairs of measurements, 7 had a significant p-value (p Conclusions: A statistically significant amount of root resorption was observed, from pre-treatment to post-treatment radiographs. All mandibular anterior teeth except the mandibular right lateral incisors showed evidence of root resorption. 展开更多
关键词 Open bite malocclusion External apical root resorption Open bite closure
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Embryogenesis,Germination,Structure and Cotyledon Dimorphism of Zea mays Embryo 被引量:2
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作者 冯九焕 徐雪宾 +3 位作者 刘向东 章崇玲 梁秀兰 吴万春 《Acta Botanica Sinica》 CSCD 2003年第6期712-723,共12页
A series of new cognitions on the morphogenesis of maize ( Zea mays L.) embryo have been obtained with scanning electron microscopy and semi-thin section techniques. 1. The proembryo. The proembryo from zygotic cell d... A series of new cognitions on the morphogenesis of maize ( Zea mays L.) embryo have been obtained with scanning electron microscopy and semi-thin section techniques. 1. The proembryo. The proembryo from zygotic cell divisions may be divided into three parts: proper, hypoblast and suspensor. The suspensor is short and small, and only exists transiently. As to the hypoblast there is a growth belt, which promotes elongation of the hypoblast. Eventually the upper portion of the hypoblast contributes to the formation of the coleorhiza and the remainder dries up, sticking to the end of the coleorhiza. 2. The maize embryo possesses dorsiventrality and cotyledon dimorphism. During early proembryo stage, the dorsiventrality appears in the proper of the embryo. On the ventral side, the cells are small with dense cytoplasm and few vacuoles. On the dorsal side, the cells are larger with lower cytoplasmic density and have more vacuoles. During later proembryo stage, the proper develops into two parts: the ventrum and the dorsurn. The ventrum rises up from the center of the ventral side. The dorsurn is composed of the marginal area of the ventral side and the whole dorsal side of the proper. During young embryo development, the ventrum differentiates into the coleoptile, apical meristem, hypocotyl, radicle and the main part of the coleorhiza. What is more important, the emergence of coleoptile primordium and radicular initials occur at the axis of the proper, then the coleoptile primordium expands from its two ends toward left and right to form a ring, and the endogenous radicular initials expand in all directions to form a conical radicular tip. All these morphogenetic activities of the ventrum follow a bilateral symmetrical pattern. The dorsurn forms the scutellum. primordium. Then the scutellum primordium, expands rapidly toward the left, right, front and back, while thickening itself, so as to make all components originating from the ventrum become hidden in the longitudinal groove of the scutellum. Lastly, the left and right lateral scales emerge from the edges of the longitudinal groove and expand toward the central line of the axis. As a consequence, morphologically, the bilateral symmetry of the ventral side of the embryo is revealed entirely. Morphogenetically, the coleoptile primordium and apical meristem in maize are similar to the coleoptile (apical cotyledon) and apex formation of the nice embryo, so the coleoptile of the maize embryo can also be considered as an apical cotyledon. The scutellum is a lateral cotyledon. These dimorphic cotyledons of the maize embryo originate from the dorsiventrality of the proper. 3. The true morphological structure of the maize embryo is recognized and its developmental stages are established. A maize embryo is a hypocotyl, in which the apical part is the shoot apex (or plumule) with the coleoptile, the central part consists mainly of the hypocotyl with a lateral cotyledon (scutellum), and the basal part is the radicle with coleorhiza. The left and right lateral scales derived from the scutellum overlap at the ventral side, leaving only two little pores at both ends of the seam from which the coleoptile and coleorhiza can be seen. The four sequential stages of maize embryonic development are as follows: (1) proembryo, stage. This stage covers a period from zygotic cell division to the appearance of the dorsum and ventrum. (2) ventrum rapid differentiation stage. (3) scutellum rapid expansion stage. (4) lateral scale development stage (or embryonic envelope formation stage). 4. To obtain a median longitudinal section perpendicular to the ventral surface is crucial for recognizing the genuine morphological structure of the maize embryo. 展开更多
关键词 Zea mays EMBRYOGENESIS hypoblast dorsiventrality cotyledon dimorphism embryonic envelope (lateral cotyledon) coleoptile (apical cotyledon)
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The Structure of Oryza Embryos and Their Dimorphic Cotyledons 被引量:2
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作者 徐雪宾 刘向东 +2 位作者 章崇玲 吴万春 韩惠珍 《Acta Botanica Sinica》 CSCD 2002年第1期15-21,共7页
It has been generally held in botany that Oryza sativa L. is a monocotyledon. Based on studies of rice embryo development we confirmed that rice embryo has two dimorphic cotyledons rather than just one cotyledo... It has been generally held in botany that Oryza sativa L. is a monocotyledon. Based on studies of rice embryo development we confirmed that rice embryo has two dimorphic cotyledons rather than just one cotyledon. In the present study we attempt to know if the morphology of embryos in other species of Oryza differs from O. sativa and if these embryos have dimorphic cotyledon. Two types of embryo structures were observed in 22 species and/or subspecies of genus Oryza under the scanning electron microscope. Type 1, the O.sativa type, which is characterized by ventral scale and lateral scales, was found in 16 species. Type 2, the O. meyeriana (Zoll. et Mor. ex Steud.) Baill. ssp. tuberculata W. C. Wu et Y. G. Lu, G. C. Wang type, with no ventral scale and lateral scales, was found in 6 species and subspecies. The embryogenic process of O.sativa and O.meyeriana sub. tuberculata showed that the scutellum primordium, coleorhiza primordium, coleoptile primordium and shoot apical meristem directly differentiate from proembryo. The former two later develop into the embryo envelope, which is the outside cotyledon; the coleoptile primordium develops into the coleoptile with the shape of inverted empty cone surrounding and covering the growth cone, which is the apical cotyledon. Both types of rice embryos have dimorphic cotyledons. The structural difference between them is that the scutellum primordium of the young embryo in type 2 does not differentiate ventral scale and lateral scales while the embryo of type 1 does. The dimorphic cotyledons of embryo of Oryza plants originate from the dorsiventrality of proembryo. 展开更多
关键词 genus Oryza EMBRYOGENESIS dimorphic cotyledon dorsiventrality embryonic envelope (outside cotyledon) scutellum and coleoptile (apical cotyledon)
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PCI中断机制初探 被引量:3
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作者 李晓钰 刘小龙 谢长生 《计算机应用研究》 CSCD 北大核心 2004年第3期91-93,共3页
首先介绍了PCI的中断结构,包括可编程中断控制和高级可编程中断控制两种范式,然后以Linux操作系统为例详细探讨了PCI的自动配置能力、共享中断的实现以及中断处理过程等几方面的关键技术。
关键词 外围部件互连(PCI) 可编程中断控制器(PIC) 高级可编程中断控制器(APIC) 中断 配置空间
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APIC简介 被引量:25
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作者 李六亿 《中华医院感染学杂志》 CAS CSCD 2003年第3期297-297,共1页
关键词 APIC 简介 医院感染
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一种基于Linux操作系统下时钟系统的改进机制 被引量:1
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作者 唐红梅 郑刚 《计算机技术与发展》 2007年第2期85-88,共4页
随着Linux操作系统的成功,改进Linux的设计和性能,使其应用于实时领域受到了越来越多人的关注。考虑到Linux目前的时钟粒度仍然粗糙,它将直接影响到整个内核的实时性能,文中提出了一种基于Linux操作系统下时钟系统的改进机制,找出修改... 随着Linux操作系统的成功,改进Linux的设计和性能,使其应用于实时领域受到了越来越多人的关注。考虑到Linux目前的时钟粒度仍然粗糙,它将直接影响到整个内核的实时性能,文中提出了一种基于Linux操作系统下时钟系统的改进机制,找出修改时钟系统提高实时性的具体方法。实验结果显示,所作改进以不大的代价有效地提高了Linux的实时性能。 展开更多
关键词 LINUX 时钟系统 定时器队列 APIC
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产教融合背景下高职物流管理专业教学改革探讨 被引量:1
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作者 潘悦 《对外经贸》 2021年第12期128-131,共4页
高职物流专业教育的使命是能够培养学生的职业核心技能,更好满足社会对人才的需求。由于高职院校对物流管理技能的认知与企业岗位实际需求存在偏差,导致学生对就业环境不够满意。在产教融合的现实背景下,通过物流管理专业教学现状分析,... 高职物流专业教育的使命是能够培养学生的职业核心技能,更好满足社会对人才的需求。由于高职院校对物流管理技能的认知与企业岗位实际需求存在偏差,导致学生对就业环境不够满意。在产教融合的现实背景下,通过物流管理专业教学现状分析,找出长期存在的问题,结合国外教育经验,对接1+X制度,提出做好组织结构调整、专业定位、课程体系变革、加强实践教学、重构评估体系、政府发挥推动作用、文化育人的策略。 展开更多
关键词 产教融合 1+X 物流管理 教学改革 APICS
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Isolation and Characterization of an Arabidopsis Bushy and Dwarf Mutant 被引量:3
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作者 戴亚 付志明 李家洋 《Acta Botanica Sinica》 CSCD 2003年第5期621-625,共5页
Apical dominance is a phenomenon that the growth of axillary meristems is inhibited by the primary shoot or inflorescence. Recent researches have begun to reveal the molecular mechanisms of apical dominance by isolati... Apical dominance is a phenomenon that the growth of axillary meristems is inhibited by the primary shoot or inflorescence. Recent researches have begun to reveal the molecular mechanisms of apical dominance by isolating and identifying mutants with altered apical dominance. Here we report isolation of a bushy and dwarf 1 (bud1) mutant from Arabidopsis thaliana L. through a T-DNA tagging approach. The phenotypes of bul1 plants include loss of apical dominance, reduced plant size and dwarfism, suggesting that the bud1 mutant may be involved in auxin metabolism, transport or signalling. Using a reporter gene driven by an auxin-responsive promoter, we found that the expression pattern of auxin response element was altered in bud1. The auxin sensitivity and transport assay indicates that these two processes are normal in bud1. These results suggest that the bud1 phenotypes may result from an alteration in auxin metabolism. Genetic analysis demonstrates that bud1 is a semidominant mutant and cosegregates with a T-DNA insertion, which indicates that BUD1 gene could be cloned by iPCR approach. 展开更多
关键词 apical dominance bud1 AUXIN Arabidopsis thaliana
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Apical bud上皮诱导脂肪间充质干细胞向成牙本质样细胞分化的研究 被引量:2
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作者 孙雅娟 李华 +2 位作者 刘娜 张博 顾斌 《中华老年口腔医学杂志》 2015年第1期7-11,共5页
目的:通过体外及体内实验探讨大鼠切牙Apical bud上皮细胞诱导大鼠脂肪来源间充质干细胞向成牙本质细胞分化的能力。方法:分离培养大鼠脂肪间充质干细胞、Apical bud上皮细胞,制备Apical bud上皮条件诱导液并体外对ADSCs诱导7d,通过实... 目的:通过体外及体内实验探讨大鼠切牙Apical bud上皮细胞诱导大鼠脂肪来源间充质干细胞向成牙本质细胞分化的能力。方法:分离培养大鼠脂肪间充质干细胞、Apical bud上皮细胞,制备Apical bud上皮条件诱导液并体外对ADSCs诱导7d,通过实时定量PCR方法检测成牙本质关键基因DMP-1及DSPP的表达。制备ADSCs及Apical bud上皮重组细胞团进行大鼠肾被膜下移植,8W后取材,分别采用HE染色、Masson三色法和免疫组化方法对移植生成物进行组织学检测。结果:Apical bud上皮诱导ADSCs后DMP-1及DSPP m R NA表达水平显著高于对照组。体内移植8W后H E染色可见管样牙本质和骨样牙本质样结构,Masson三色法可以观察到有绿色的牙本质样结构,免疫组化检测中CK14染色阳性,DSPP染色阳性。结论:Apical bud上皮细胞在体外能够诱导ADSCs向成牙本质细胞分化,且细胞重组在体内可以构建出牙本质样结构。 展开更多
关键词 APICAL bud上皮细胞 脂肪间充质干细胞 成牙本质细胞 分化
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基于APIC时钟的嵌入式Linux内核实时化研究 被引量:2
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作者 侯峰 童晓阳 《现代电子技术》 2010年第14期193-195,共3页
在分析目前Linux的各种实时化方法的基础上,提出了基于APIC时钟修改的方法,以获得更高的硬实时性能。对APIC中断函数进行修改,将APIC中断和8254中断排序,使得硬实时中断的优先级大于普通8254中断,从而获得了更高的实时性能。多组仿真实... 在分析目前Linux的各种实时化方法的基础上,提出了基于APIC时钟修改的方法,以获得更高的硬实时性能。对APIC中断函数进行修改,将APIC中断和8254中断排序,使得硬实时中断的优先级大于普通8254中断,从而获得了更高的实时性能。多组仿真实验验证了该方法的有效性。 展开更多
关键词 嵌入式系统 实时化改造 LINUX APIC
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