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Robust Facial Biometric Authentication System Using Pupillary Light Reflex for Liveness Detection of Facial Images
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作者 Puja S.Prasad Adepu Sree Lakshmi +5 位作者 Sandeep Kautish Simar Preet Singh Rajesh Kumar Shrivastava Abdulaziz S.Almazyad Hossam M.Zawbaa Ali Wagdy Mohamed 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第4期725-739,共15页
Pupil dynamics are the important characteristics of face spoofing detection.The face recognition system is one of the most used biometrics for authenticating individual identity.The main threats to the facial recognit... Pupil dynamics are the important characteristics of face spoofing detection.The face recognition system is one of the most used biometrics for authenticating individual identity.The main threats to the facial recognition system are different types of presentation attacks like print attacks,3D mask attacks,replay attacks,etc.The proposed model uses pupil characteristics for liveness detection during the authentication process.The pupillary light reflex is an involuntary reaction controlling the pupil’s diameter at different light intensities.The proposed framework consists of two-phase methodologies.In the first phase,the pupil’s diameter is calculated by applying stimulus(light)in one eye of the subject and calculating the constriction of the pupil size on both eyes in different video frames.The above measurement is converted into feature space using Kohn and Clynes model-defined parameters.The Support Vector Machine is used to classify legitimate subjects when the diameter change is normal(or when the eye is alive)or illegitimate subjects when there is no change or abnormal oscillations of pupil behavior due to the presence of printed photograph,video,or 3D mask of the subject in front of the camera.In the second phase,we perform the facial recognition process.Scale-invariant feature transform(SIFT)is used to find the features from the facial images,with each feature having a size of a 128-dimensional vector.These features are scale,rotation,and orientation invariant and are used for recognizing facial images.The brute force matching algorithm is used for matching features of two different images.The threshold value we considered is 0.08 for good matches.To analyze the performance of the framework,we tested our model in two Face antispoofing datasets named Replay attack datasets and CASIA-SURF datasets,which were used because they contain the videos of the subjects in each sample having three modalities(RGB,IR,Depth).The CASIA-SURF datasets showed an 89.9%Equal Error Rate,while the Replay Attack datasets showed a 92.1%Equal Error Rate. 展开更多
关键词 SIFT PUPIL CASIA-SURF pupillary light reflex replay attack dataset brute force
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Is there a need for universal double reflex testing of HBsAg-positive individuals for hepatitis D infection?
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作者 Zaigham Abbas Minaam Abbas 《World Journal of Hepatology》 2024年第3期300-303,共4页
Hepatitis D virus(HDV)can infect HBsAg-positive individuals,causing rapid fibrosis progression,early decompensation,increased hepatocellular carcinoma risk,and higher mortality than hepatitis B virus(HBV)mono-infectio... Hepatitis D virus(HDV)can infect HBsAg-positive individuals,causing rapid fibrosis progression,early decompensation,increased hepatocellular carcinoma risk,and higher mortality than hepatitis B virus(HBV)mono-infection.Most countries lack high-quality HDV prevalence data,and the collection techniques employed often bias published data.In recent meta-analyses,HDV prevalence in HBsAg-positive patients reaches 5%-15%and is even significantly higher in endemic areas.Since HBV vaccination programs were implemented,HDV prevalence has decreased among younger populations.However,owing to immigrant influx,it has increased in some Western countries.The current practice of HDV screening in HBsAg-positive individuals is stepwise,based on physician’s discretion,and limited to at-risk populations and may require numerous visits.Double reflex testing,which includes anti-HDV testing in all HBsAg-positive individuals and then HDV RNA testing for anti-HDV-positive ones,is uncommon.Reflex testing can identify more HDV infection cases and link identified patients to further care and follow-up.Moreover,laboratory-based double reflex screening is less biased than physician-led testing.Therefore,health-care providers should learn about reflex testing,and federal and provincial hepatitis control programs should implement laboratory-based double reflex testing to obtain reliable HDV prevalence estimates.The test’s cost-effectiveness depends on the number of HBV-positive patients screened to identify one HDV-positive patient.Such testing may be viable in areas with low HBsAg but high HDV prevalence.However,its economic impact on areas with low HDV prevalence needs further study. 展开更多
关键词 Anti-hepatitis D virus antibody HBSAG Hepatitis D virus RNA Hepatitis B Hepatitis D reflex testing
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Nursing Care of 10 Patients with Vasovagal Reflex Caused by Artificial Liver Support System Treatment
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作者 Yingying Zhang 《Open Journal of Nursing》 2024年第5期177-182,共6页
This study outlines the essential nursing strategies employed in the care of 10 patients experiencing vascular vagal reflex, managed with artificial liver support systems. It highlights a holistic nursing approach tai... This study outlines the essential nursing strategies employed in the care of 10 patients experiencing vascular vagal reflex, managed with artificial liver support systems. It highlights a holistic nursing approach tailored to the distinct clinical manifestations of these patients. Key interventions included early detection of psychological issues prior to initiating treatment, the implementation of comprehensive health education, meticulous monitoring of vital signs throughout the therapy, prompt emergency interventions when needed, adherence to prescribed medication protocols, and careful post-treatment observations including venous catheter management. Following rigorous treatment and dedicated nursing care, 7 patients demonstrated significant improvement and were subsequently discharged. 展开更多
关键词 Vasovagal reflex Artificial Liver Support System Nursing Care
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Infant’s Sigh Breathing Matters—The Role of the Hering-Breuer Deflation Reflex in Bronchial Decongestion
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作者 Karine Truflandier Kevin Albert Jean-Jacques Moraine 《Open Journal of Therapy and Rehabilitation》 2024年第3期197-212,共16页
Background: The prolonged slow expiratory (PSE) technique can induce sigh breaths related to the Hering-Breuer reflex in children.PSE is a specific chest physiotherapy technique often used in children to help with the... Background: The prolonged slow expiratory (PSE) technique can induce sigh breaths related to the Hering-Breuer reflex in children.PSE is a specific chest physiotherapy technique often used in children to help with the clearance of secretions, reduce pulmonary obstruction and decrease ventilatory effort. Purpose: The main objective of this review was to synthesize and clarify the existing knowledge of the physiological mechanism behind the Hering-Breuer reflex and its utility in the PSE technique. The secondary objective was to provide an overview of PSE which is probably the main mechanical feature for mucus clearance in infants and to identify gaps and any further research required. Method: A comprehensive literature search was performed using PubMed/MEDLINE and Ovid EMBASE, from 1968 to January 2024, using search terms relating to “Interaction of Hering-Breuer reflex and chest physiotherapy therapy, sigh breath in infants and prolonged slow expiration technique” to create an overview of the advances and gaps in current knowledge of PSE. Result: The data obtained following treatment with PSE maneuvers in infants with histories of recurrent wheezing shows that the presence of sighs could be the main active principle of treatment. Conclusion: Changes in volume induced by PSE technique and, effects from crying may stimulate the Hering-Breuer deflation reflex and sighs in turn improving alveolar ventilation as well as lung volume in infants. 展开更多
关键词 Hering-Breuer (HB) reflex Sigh Breath INFANTS Prolonged Slow Expiration Technique Large Volume Chest Physiotherapy
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WEAKLY ALGEBRAIC REFLEXIVITY AND STRONGLY ALGEBRAIC REFLEXIVITY
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作者 Tao Changli Lu Shijie Chen PeixinDept.ofAppl.Math.,ShandongUniv.ofSci.andTech.,Taian271019,China,Dept.ofMath.,ZhejiangUniv.,Hangzhou310027,China 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2002年第2期193-198,共6页
Algebraic reflexivity introduced by Hadwin is related to linear interpolation.In this paper,the concepts of weakly algebraic reflexivity and strongly algebraic reflexivity which are also related to linear interpolat... Algebraic reflexivity introduced by Hadwin is related to linear interpolation.In this paper,the concepts of weakly algebraic reflexivity and strongly algebraic reflexivity which are also related to linear interpolation are introduced.Some properties of them are obtained and some relations between them revealed 展开更多
关键词 linear interpolation algebraic reflexivity weakly algebraic reflexivity strongly algebraic reflexIVITY surperreflexivity
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Alterations in blink and masseter reflex latencies in older adults with neurocognitive disorder and/or diabetes mellitus
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作者 Jaime Alberto Bricio-Barrios Eder Ríos-Bracamontes +7 位作者 Mónica Ríos-Silva Miguel Huerta Walter Serrano-Moreno JoséEnrique Barrios-Navarro Genaro Gabriel Ortiz Miguel Huerta-Trujillo JoséGuzmán-Esquivel Xóchitl Trujillo 《World Journal of Clinical Cases》 SCIE 2022年第1期177-188,共12页
BACKGROUND Blink and masseter reflexes provide reliable,quantifiable data on the function of the central nervous system:Delayed latencies have been found in patients with neurocognitive disorder(ND)and type 2 diabetes... BACKGROUND Blink and masseter reflexes provide reliable,quantifiable data on the function of the central nervous system:Delayed latencies have been found in patients with neurocognitive disorder(ND)and type 2 diabetes mellitus(T2DM),but this has not been studied in patients with both pathologies.AIM To investigate if older adults with ND plus T2DM have prolonged latencies of blink and masseter-reflex and if they were associated with disease progression.METHODS This cross-sectional study included 227 older adults(>60 years)from Colima,Mexico.Neurocognitive disorder was identified by a neuropsychological battery test,and T2DM identified by medical history,fasting glucose,and glycosylated hemoglobin.Latencies in the early reflex(R1),ipsilateral late(R2),and contralateral late(R2c)components of the blink reflex were analyzed for all subjects,and 183 subjects were analyzed for latency of the masseter reflex.RESULTS In 20.7%of participants,ND was detected.In 37%,T2DM was detected.Latencies in R1,R2,and R2c were significantly prolonged for groups with ND plus T2DM,ND,and T2DM,compared with the control group(P<0.0001).The masseter reflex was only prolonged in older adults(regardless of T2DM status)with ND vs controls(P=0.030).In older adults with ND and without T2DM,the more the cognitive impairment progressed,the more prolonged latencies in R2 and R2c presented(P<0.01).CONCLUSION These findings suggest that blink and masseter reflexes could be used to evaluate possible changes in brainstem circuits in older adults with ND and T2DM. 展开更多
关键词 Blink reflex Masseter reflex Brainstem reflexes Neurocognitive disorder Type 2 diabetes mellitus Older adults
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Reflexive solution to a system of matrix equations 被引量:2
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作者 常海霞 王卿文 《Journal of Shanghai University(English Edition)》 CAS 2007年第4期355-358,共4页
We derive necessary and sufficient conditions for the existence and an expression of the (anti)reflexive solution with respect to the nontrivial generalized reflection matrix P to the system of complex matrix equati... We derive necessary and sufficient conditions for the existence and an expression of the (anti)reflexive solution with respect to the nontrivial generalized reflection matrix P to the system of complex matrix equations AX = B and XC = D. The explicit solutions of the approximation problem min x∈Ф ||X - E||F was given, where E is a given complex matrix and Ф is the set of all reflexive (or antireflexive) solutions of the system mentioned above, and ||·|| is the Frobenius norm. Furthermore, it was pointed that some results in a recent paper are special cases of this paper. 展开更多
关键词 system of matrix equations Moore-Penrose inverse reflexive matrix antireflexive matrix Frobenius norm
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Investigation of fundo-antral reflex in human beings 被引量:1
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作者 Satish SC Rao Anjana Kumar +2 位作者 Brent Harris Bruce Brown Konrad S Schulze 《World Journal of Gastroenterology》 SCIE CAS CSCD 2005年第42期6676-6680,共5页
AIM: To examine the sensory and motor response(s) of the stomach following fundic distention and to assess whether cholinergic mechanisms influence these responses. METHODS: Fundic tone, gastric sensory responses ... AIM: To examine the sensory and motor response(s) of the stomach following fundic distention and to assess whether cholinergic mechanisms influence these responses. METHODS: Fundic tone, gastric sensory responses and antral motility were evaluated in eight healthy volunteers after a probe with two sensors was placed in the antrum and a highly compliant balloon in the fundus. Isobaric balloon distentions were performed with a barostat. Study was repeated in six volunteers after intravenous atropine was given. RESULTS: Fundic antral contractions curve was higher First sensation distention induced large amplitude in all subjects. The area under the (P〈0.05) during fundic distention. was reported at 12±4 mmHg, moderate sensation at 18±4 mmHg and discomfort at 21±4 mmHg. Discomfort was associated with a decrease in antral motility. After atropine was given, the area under the curve of pressure waves and fundic tone decreased (P〈0.05). Sensory thresholds were not affected. CONCLUSIONS: Fundic balloon distention induces an antral motor response, the fundo-antral reflex, which in part may be mediated by cholinergic mechanisms. 展开更多
关键词 Gastric motility reflex Fundo-antral reflex SENSATION
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REFLEX自锁钢板治疗颈椎间盘突出的临床疗效
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作者 施克勤 陶波 《齐齐哈尔医学院学报》 2004年第6期621-622,共2页
目的 探讨应用REFLEX颈椎前路自锁钢板治疗颈椎间盘突出的远期疗效。方法  4 6例患者经前路减压植骨融合REFLEX自锁钢板固定。结果  4 4例患者获得长期随访 ,最长 2 3个月 ,最短 14个月 ,平均 17个月。所有患者均于 13~ 16周获得骨... 目的 探讨应用REFLEX颈椎前路自锁钢板治疗颈椎间盘突出的远期疗效。方法  4 6例患者经前路减压植骨融合REFLEX自锁钢板固定。结果  4 4例患者获得长期随访 ,最长 2 3个月 ,最短 14个月 ,平均 17个月。所有患者均于 13~ 16周获得骨性愈合。术后未出现椎间高度丢失现象 ,无钢板螺钉松动 ,植骨块滑脱。获得随访病例绝大多数神经功能得到不同程度的改善。结论 应用RE 展开更多
关键词 reflex自锁钢板 颈椎间盘突出 前路减压 神经功能
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ON TOPOLOGICAL REFLEXIVITY OF THE SPACES OF DERIVATIONS ON OPERATOR ALGEBRAS
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作者 Jing Wu Lu Shijie Han GuangguoDept. of Math.,Zhejiang Univ.,Hangzhou 310027. 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2002年第1期75-79,共5页
It is proved that the spaces of derivations on some operator algebras are topologically reflexive in the weak operator topology.
关键词 DERIVATION reflexIVITY von Neumann algebra reflexive algebra.
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Unilateral Reference Values for Hoffmann’s Reflex in Patients with Suspected Lumbosacral Radiculopathies
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作者 I-Hsuan Tsai Hao-Hsuan Tsai 《Open Journal of Orthopedics》 2013年第3期178-182,共5页
Unilateral reference values for Hoffmann’s amplitude could be applied to the diagnosis of lumbosacral radiculopathy, especially in patients with bilateral lesions. Here, we assessed Hoffmann’s reflex by measuring H-... Unilateral reference values for Hoffmann’s amplitude could be applied to the diagnosis of lumbosacral radiculopathy, especially in patients with bilateral lesions. Here, we assessed Hoffmann’s reflex by measuring H-wave amplitude and the ratio of H-wave amplitude to M-wave amplitude (the H/M ratio). We performed a cross-sectional survey of patients from a Taiwan rehabilitation center (n = 64, age 20 - 87) who presented with lower back pain that radiated to the leg and received a referral for electrodiagnostic examinations. Reference values for H-wave profile parameters were determined using data from lumbosacral radiculopathy-negative patients (n = 10, age 22 - 53), who had normal big toe test results, ankle reflex test results, motor and sensory nerve conductive studies and F-wave latency and who displayed no evidence of radiculopathy in electromyography and imaging studies. The 50th percentile values for H/M ratio and H-wave amplitude were 28% and 6.25 mV, respectively. An H-wave profile th percentile (H/M ratio bosacral radiculopathy (n = 64). Approximately 41% of patients with an H-wave profile th percentile showed electromyography-confirmed chronic radiculopathy. Electromyography-confirmed current radiculopathy was observed in 35% of patients with an H/R 展开更多
关键词 Hoffmann’s reflex H-reflex Electromyography Electrodiagnostic Studies LUMBOSACRAL RADICULOPATHY SCIATICA
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On Edge Irregular Reflexive Labeling of Categorical Product of Two Paths
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作者 Muhammad Javed Azhar Khan Muhammad Ibrahim Ali Ahmad 《Computer Systems Science & Engineering》 SCIE EI 2021年第3期485-492,共8页
Among the huge diversity of ideas that show up while studying graph theory,one that has obtained a lot of popularity is the concept of labelings of graphs.Graph labelings give valuable mathematical models for a wide s... Among the huge diversity of ideas that show up while studying graph theory,one that has obtained a lot of popularity is the concept of labelings of graphs.Graph labelings give valuable mathematical models for a wide scope of applications in high technologies(cryptography,astronomy,data security,various coding theory problems,communication networks,etc.).A labeling or a valuation of a graph is any mapping that sends a certain set of graph elements to a certain set of numbers subject to certain conditions.Graph labeling is a mapping of elements of the graph,i.e.,vertex and for edges to a set of numbers(usually positive integers),called labels.If the domain is the vertex-set or the edge-set,the labelings are called vertex labelings or edge labelings respectively.Similarly,if the domain is V(G)[E(G)],then the labeling is called total labeling.A reflexive edge irregular k-labeling of graph introduced by Tanna et al.:A total labeling of graph such that for any two different edges ab and a'b'of the graph their weights has wt_(x)(ab)=x(a)+x(ab)+x(b) and wt_(x)(a'b')=x(a')+x(a'b')+x(b') are distinct.The smallest value of k for which such labeling exist is called the reflexive edge strength of the graph and is denoted by res(G).In this paper we have found the exact value of the reflexive edge irregularity strength of the categorical product of two paths (P_(a)×P_(b))for any choice of a≥3 and b≥3. 展开更多
关键词 Edge irregular reflexive labeling reflexive edge strength categorical product of two paths
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Note on Reflexive Algebras with Non-distribut iveInvariant Lattices
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作者 赵君喜 《Chinese Quarterly Journal of Mathematics》 CSCD 1998年第4期59-63, ,共5页
In this note,we discuss some properties of reflexive algebras on a Hilbert space with invariant subspace lattices as realizations of the pentagon and the double triangle and give some results concerning hyperreflexivi... In this note,we discuss some properties of reflexive algebras on a Hilbert space with invariant subspace lattices as realizations of the pentagon and the double triangle and give some results concerning hyperreflexivity,automorphism and finite rank operators. 展开更多
关键词 subspace lattice reflexive algebra hyperreflexivity
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Strongly s-Reflexive Rings Relative to a Monoid
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作者 PENG Zhai-ming GU Qin-qin ZHANG Rui-rui 《Chinese Quarterly Journal of Mathematics》 2018年第3期260-271,共12页
For a monoid M and an endomorphism α of a ring R, we introduce the notion of strongly M-α-reflexive rings and study its properties. For an u.p.-monoid M and a right Ore ring R with its classical right quotient ring ... For a monoid M and an endomorphism α of a ring R, we introduce the notion of strongly M-α-reflexive rings and study its properties. For an u.p.-monoid M and a right Ore ring R with its classical right quotient ring Q, we prove that R is strongly M-α-reflexive if and only if Q is strongly M-α-reflexive, where R is α-rigid, α is an epimorphism of R. The relationship between some special subrings of upper triangular matrix rings and strongly M-α-reflexive rings is also investigated. Several known results similar to strongly M-α-reversible rings are obtained. 展开更多
关键词 Unique product MONOID a-reflexive RING STRONGLY M-a-reflexive RING strictlytotally ordered MONOID
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用Reflexive ACL实现网络单向访问
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作者 张昆朋 《现代计算机》 2006年第8期30-31,52,共3页
通过建立路由器访问控制列表,可以控制任何IP地址对网络的访问,但要实现网络的单向访问,一般的访问列表是无法做到的。本文从实际应用的角度出发,利用一种特殊的ACL-ReflexiveACL,即自反访问控制列表,来实现网络的单向访问,并分析、阐... 通过建立路由器访问控制列表,可以控制任何IP地址对网络的访问,但要实现网络的单向访问,一般的访问列表是无法做到的。本文从实际应用的角度出发,利用一种特殊的ACL-ReflexiveACL,即自反访问控制列表,来实现网络的单向访问,并分析、阐述了它的配置过程。 展开更多
关键词 reflexIVE ACL 路由器 单向访问
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Nilpotent Elements and Nil-Reflexive Property of Generalized Power Series Rings
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作者 Eltiyeb Ali 《Advances in Pure Mathematics》 2022年第11期676-692,共17页
Let R be a ring and (S,≤) a strictly ordered monoid. In this paper, we deal with a new approach to reflexive property for rings by using nilpotent elements, in this direction we introduce the notions of generalized p... Let R be a ring and (S,≤) a strictly ordered monoid. In this paper, we deal with a new approach to reflexive property for rings by using nilpotent elements, in this direction we introduce the notions of generalized power series reflexive and nil generalized power series reflexive, respectively. We obtain various necessary or sufficient conditions for a ring to be generalized power series reflexive and nil generalized power series reflexive. Examples are given to show that, nil generalized power series reflexive need not be generalized power series reflexive and vice versa, and nil generalized power series reflexive but not semicommutative are presented. We proved that, if R is a left APP-ring, then R is generalized power series reflexive, and R is nil generalized power series reflexive if and only if R/I is nil generalized power series reflexive. Moreover, we investigate ring extensions which have roles in ring theory. 展开更多
关键词 Left APP-Ring Generalized Power Series reflexive Ring Nil Generalized Power Series reflexive Ring S-Quasi Armendariz Ring Semiprime Ring Semicommutative Ring
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Electroacupuncture at ST36 modulates gastric motility via vagovagal and sympathetic reflexes in rats 被引量:16
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作者 Meng-Jiang Lu Zhi Yu +2 位作者 Yan He Yin Yin Bin Xu 《World Journal of Gastroenterology》 SCIE CAS 2019年第19期2315-2326,共12页
BACKGROUND Electroacupuncture(EA) at ST36 can significantly improve gastrointestinal symptoms, especially in promoting gastrointestinal motility. The automatic nervous system plays a main role in EA, but few studies e... BACKGROUND Electroacupuncture(EA) at ST36 can significantly improve gastrointestinal symptoms, especially in promoting gastrointestinal motility. The automatic nervous system plays a main role in EA, but few studies exist on how vagovagal and sympathetic reflexes affect EA to regulate gastrointestinal motility.AIM To study the role of vagovagal and sympathetic reflexes in EA at ST36, as well as the associated receptor subtypes that are involved.METHODS Gastric motility was measured with a manometric balloon placed in the gastric antrum area in anesthetized animals. The peripheral nervous discharge was measured using a platinum electrode hooking the vagus or greater splanchnic nerve, and the central nervous discharge was measured with a glass microelectrode in the dorsal motor nucleus of the vagus(DMV). The effects and mechanisms of EA at ST36 were explored in male Sprague-Dawley rats which were divided in to a control group, vagotomy group, sympathectomy group, and microinjection group [including an artificial cerebrospinal fluid group, glutamate(L-Glu) group, and γ-aminobutyric acid(GABA) group] and in genetically modified male mice [β1β2 receptor-knockout(β1β2^(-/-)) mice, M2M3 receptorknockout(M2M3^(-/-)) mice, and wild-type control mice].RESULTS EA at ST36 promoted gastric motility during 30-120 s. During EA, both vagus and sympathetic nerve discharges increased, with a much higher frequency of vagus nerve discharge than sympathetic discharge. The gastric motility mediated by EA at ST36 was interdicted by vagotomy. However, gastric motility mediated by EA at ST36 was increased during 0-120 s by sympathectomy, which eliminated the delay effect of EA during 0-30 s, but it was lower than the control group during 30-120 s. Using gene knockout mice and their wild-type controls to explore the receptor mechanisms, we found that EA at ST36 decreased gastric motility in M2/3^(-/-) mice, and promoted gastric motility in β1/2^(-/-) mice. Extracellular recordings showed that EA at ST36 increased spikes of the DMV. Microinjection of L-Glu into the DMV increased gastric motility, while EA at ST36 decreased gastric motility during 0-60 s, and promoted gastric motility during 60-120 s.Injection of GABA reduced or increased gastric motility, and reduced the promoting gastric motility effect of EA at ST36.CONCLUSION These data suggest that EA at ST36 modulates gastric motility via vagovagal and sympathetic reflexes mediated through M2/3 and β1/2 receptors, respectively.Sympathetic nerve activity mediated through β1/2 receptors is associated with an early delay in modulation of gastric motility by EA at ST36. 展开更多
关键词 Gastric MOTILITY ELECTROACUPUNCTURE Vagovagal reflex SYMPATHETIC nerve RATS
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Adaptive Walking of a Quadrupedal Robot Based on Layered Biological Reflexes 被引量:10
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作者 ZHANG Xiuli E Mingcheng +1 位作者 ZENG Xiangyu ZHENG Haojun 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2012年第4期654-664,共11页
A multiple-legged robot is traditionally controlled by using its dynamic model.But the dynamic-model-based approach fails to acquire satisfactory performances when the robot faces rough terrains and unknown environmen... A multiple-legged robot is traditionally controlled by using its dynamic model.But the dynamic-model-based approach fails to acquire satisfactory performances when the robot faces rough terrains and unknown environments.Referring animals' neural control mechanisms,a control model is built for a quadruped robot walking adaptively.The basic rhythmic motion of the robot is controlled by a well-designed rhythmic motion controller(RMC) comprising a central pattern generator(CPG) for hip joints and a rhythmic coupler(RC) for knee joints.CPG and RC have relationships of motion-mapping and rhythmic couple.Multiple sensory-motor models,abstracted from the neural reflexes of a cat,are employed.These reflex models are organized and thus interact with the CPG in three layers,to meet different requirements of complexity and response time to the tasks.On the basis of the RMC and layered biological reflexes,a quadruped robot is constructed,which can clear obstacles and walk uphill and downhill autonomously,and make a turn voluntarily in uncertain environments,interacting with the environment in a way similar to that of an animal.The paper provides a biologically inspired architecture,with which a robot can walk adaptively in uncertain environments in a simple and effective way,and achieve better performances. 展开更多
关键词 legged robot motion control central pattern generator(CPG) biological reflex
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The effects of androgen on penile reflex, erectile response to electrical stimulation and penile NOS activity in the rat 被引量:7
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作者 Seong Il Seo Soo Woong Kim Jae-Seung Paick 《Asian Journal of Andrology》 SCIE CAS CSCD 1999年第4期169-174,共6页
Aim: To investigate the effects of androgen on penile erection through the reflex arc and penile corpus cavernosum,and study the respective roles of testosterone (T) and dihydrotestosterone (DHT) in penile erection in... Aim: To investigate the effects of androgen on penile erection through the reflex arc and penile corpus cavernosum,and study the respective roles of testosterone (T) and dihydrotestosterone (DHT) in penile erection in rats. Methods:Male Sprague-Dawley rats were castrated and implanted with silastic brand silicone tube containing T or DHT, with orwithout daily injections of a 5α-reductase inhibitor, MK-434. The penile reflex, erectile response to electrical stimula-tion (ES) of the cavernous nerves and penile nitric-oxide synthase (NOS) activity were observed under varying andro-genic status. Results: Penile reflex erection in the rat was, on the whole, related to serum T levels though the numberof glans engorgements was not. The number of cups and flips was significantly decreased by castration, and restoredto the control level by T supplementation. Erectile response to ES and NOS activity in penile tissue was also related toserum T level. T administered together with a 5α-reductase inhibitor no longer restored the number of reflex erection,erectile responses to ES and NOS activity in the corpus cavernosum. Conclusion: Androgen influenced the penile re-flex arc, corpus cavernosum, and the perineal striated muscles. In reflex erection, erectile response to ES and penileNOS activity in the rat, T seems to be first converted to DHT, the more active androgen modality. (Asian J Androl1999 Dec; 1: 169-174) 展开更多
关键词 ANDROGENS penile erection reflex electric stimulation nitric-oxide synthase
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THE GENERALIZED REFLEXIVE SOLUTION FOR A CLASS OF MATRIX EQUATIONS (AX-B,XC=D) 被引量:7
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作者 李范良 胡锡炎 张磊 《Acta Mathematica Scientia》 SCIE CSCD 2008年第1期185-193,共9页
In this article, the generalized reflexive solution of matrix equations (AX = B, XC = D) is considered. With special properties of generalized reflexive matrices, the necessary and sufficient conditions for the solv... In this article, the generalized reflexive solution of matrix equations (AX = B, XC = D) is considered. With special properties of generalized reflexive matrices, the necessary and sufficient conditions for the solvability and the general expression of the solution are obtained. Moreover, the related optimal approximation problem to a given matrix over the solution set is solved. 展开更多
关键词 Matrix equations generalized reflexive matrix optimal approximation
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