The power supplies of wireless sensor networks (WSNs) are not replaceable orrechargeable forsensors. For reducing the communication protocols’ impact onthe sensor network’s energy dissipation,various protocols or me...The power supplies of wireless sensor networks (WSNs) are not replaceable orrechargeable forsensors. For reducing the communication protocols’ impact onthe sensor network’s energy dissipation,various protocols or mechanisms havebeen proposed. Therefore, this article proposesa stable random number-basedLEACH protocol to stabilize the random number generation toimprove the CHselection efficiency. The wireless sensor network’s average node energy (ANE)ismultiplied by the random number that relies on the nodes’ energy. A nodegrade algorithm(NGA) based relay selection is introduced for inter andintracluster communication for energy efficiencyenhancement. The proposed NGA calculates the grade of a node using residual energy,distance from CHs,and its traffic parameters. Based on the simulation results, the proposedSRN-LEACH protocol shows superior performance as compared to existing protocolsincludingreduced energy dissipation, improved communication quality, andNLT. The proposed methodattains a minimum average delay of 0.136ms, 0.95% PDR, 148kbps TP rate, and 98% NLT.展开更多
In Mobile Ad Hoc Networks(MANET),Quality of Service(QoS)is an important factor that must be analysed for the showing the better performance.The Node Quality-based Clustering Algorithm using Fuzzy-Fruit Fly Optimiza-ti...In Mobile Ad Hoc Networks(MANET),Quality of Service(QoS)is an important factor that must be analysed for the showing the better performance.The Node Quality-based Clustering Algorithm using Fuzzy-Fruit Fly Optimiza-tion for Cluster Head and Gateway Selection(NQCAFFFOCHGS)has the best network performance because it uses the Improved Weighted Clustering Algo-rithm(IWCA)to cluster the network and the FFO algorithm,which uses fuzzy-based network metrics to select the best CH and entryway.However,the major drawback of the fuzzy system was to appropriately select the membership func-tions.Also,the network metrics related to the path or link connectivity were not considered to effectively choose the CH and gateway.When learning fuzzy sets,this algorithm employs a new Continuous Action-set Learning Automata(CALA)approach that correctly modifies and chooses the fuzzy membership functions.Despite the fact that it extends the network’s lifespan,it does not assist in the detection of defective nodes in the routing route.Because of this,a new Fault Tolerance(NQCAEFFFOCHGS-FT)mechanism based on the Distributed Connectivity Restoration(DCR)mechanism is proposed,which allows the net-work to self-heal as a consequence of the algorithm’s self-healing capacity.Because of the way this method is designed,node failures may be utilised to rebuild the network topology via the use of cascaded node moves.Founded on the fractional network information and topologic overhead related with each node,the DCR is suggested as an alternative to the DCR.When compared to the NQCAFFFOCHGS algorithm,the recreation results display that the proposed NQCAEFFFOCHGS-FT algorithm improves network performance in terms of end-to-end delay,energy consumption,Packet Loss Ratio(PLR),Normalized Routing Overhead(NRO),and Balanced Load Index(BLI).展开更多
BACKGROUND Malignant proliferating trichilemmal tumor(MPTT)is an infrequent malignant neoplasm originating from cutaneous appendages,with only a handful of documented cases.This report delineates a unique instance of ...BACKGROUND Malignant proliferating trichilemmal tumor(MPTT)is an infrequent malignant neoplasm originating from cutaneous appendages,with only a handful of documented cases.This report delineates a unique instance of MPTT situated in the neck,accompanied by lymph node metastasis.A comprehensive exposition of its clinical trajectory and imaging manifestation is presented,aiming to enhance comprehension and management of this atypical ailment.CASE SUMMARY Patient concerns:A 79-year-old male presented with a longstanding right neck mass persisting for over six decades,exhibiting recent enlargement over the past year.Diagnoses:Enhanced magnetic resonance imaging of the neck unveiled an elliptical mass on the right neck side,characterized by an ill-defined border and a heterogeneous signal pattern.The mass exhibited subdued signal intensity on T1-weighted imaging(T1WI)and a heterogeneous high signal on T2-weighted imaging(T2WI),interspersed with a lengthy T1 and T2 cystic signal motif.Close anatomical association with the submandibular gland joint was noted,and intravenous gadolinium diethylene triamine pentaacetic acid administration facilitated conspicuous enhancement.Substantial enhancement of the solid segment prompted an initial preoperative diagnosis of malignant nerve sheath tumor.However,post-surgery histopathological and immunohistochemical analysis conclusively confirmed the diagnosis as malignant hyperplastic external hair root sheath tumor.Intervention:Complete excision of the tumor was successfully executed.Outcomes:The patient experienced a favorable postoperative recovery.CONCLUSION Malignant proliferative trichilemmal tumor external hair root sheath tumor is a cystic-solid lesion,appearing as low signal on T1WI images or high signal on T2WI with enhancement of the solid component.Suspicions of malignancy are heightened when the tumor border is indistinct,tissue planes are breached,or when linear or patchy high signals are observed in the subcutaneous tissue on T1 liver acquisition with volume accelerat展开更多
Head and neck squamous cell carcinoma(HNSCC)is a highly aggressive tumor and the sixth most common cancer worldwide.Current treatment strategies for HNSCC are surgery,radiotherapy,chemotherapy,immunotherapy or combina...Head and neck squamous cell carcinoma(HNSCC)is a highly aggressive tumor and the sixth most common cancer worldwide.Current treatment strategies for HNSCC are surgery,radiotherapy,chemotherapy,immunotherapy or combinatorial therapies.However,the overall 5-year survival rate of HNSCC patients remains at about 50%.Cancer stem cells(CSCs),a small population among tumor cells,are able to self-renew and differentiate into different tumor cell types in a hierarchical manner,similar to normal tissue.In HNSCC,CSCs are proposed to be responsible for tumor initiation,progression,metastasis,drug resistance,and recurrence.In this review,we discuss the molecular and cellular characteristics of CSCs in HNSCC.We summarize current approaches used in the literature for identification of HNSCC CSCs,and mechanisms required for CSC regulation.We also highlight the role of CSCs in treatment failure and therapeutic targeting options for eliminating CSCs in HNSCC.展开更多
In the past few decades,Energy Efficiency(EE)has been a significant challenge in Wireless Sensor Networks(WSNs).WSN requires reduced transmission delay and higher throughput with high quality services,it further pays ...In the past few decades,Energy Efficiency(EE)has been a significant challenge in Wireless Sensor Networks(WSNs).WSN requires reduced transmission delay and higher throughput with high quality services,it further pays much attention in increased energy consumption to improve the network lifetime.To collect and transmit data Clustering based routing algorithm is considered as an effective way.Cluster Head(CH)acts as an essential role in network connectivity and perform data transmission and data aggregation,where the energy consumption is superior to non-CH nodes.Conventional clustering approaches attempts to cluster nodes of same size.Moreover,owing to randomly distributed node distribution,a cluster with equal nodes is not an obvious possibility to reduce the energy consumption.To resolve this issue,this paper provides a novel,Balanced-Imbalanced Cluster Algorithm(B-IBCA)with a Stabilized Boltzmann Approach(SBA)that attempts to balance the energy dissipation across uneven clusters in WSNs.B-IBCA utilizes stabilizing logic to maintain the consistency of energy consumption among sensor nodes’.So as to handle the changing topological characteristics of sensor nodes,this stability based Boltzmann estimation algorithm allocates proper radius amongst the sensor nodes.The simulation shows that the proposed B-IBCA outperforms effectually over other approaches in terms of energy efficiency,lifetime,network stability,average residual energy and so on.展开更多
Mobile Ad hoc Network (MANET) is a significant concept of wireless networks which comprises of thousands of nodes that are mobile as well as autonomous and they do not requires any existing network infrastructure. The...Mobile Ad hoc Network (MANET) is a significant concept of wireless networks which comprises of thousands of nodes that are mobile as well as autonomous and they do not requires any existing network infrastructure. The autonomous nodes can freely and randomly move within the network which can create temporary dynamic network and these networks can change their topology frequently. The security is the primary issue in MANET which degrades the network performance significantly. In this paper, cluster based malicious node detection methodology is proposed to detect and remove the malicious nodes. Each node within the cluster gets the cluster key from the cluster head and this key is used for the data transaction between cluster head and node. The cluster head checks this key for every data transaction from node and match with their cluster table. If match is valid, and then only it will recognize that this node is belongs to this cluster, otherwise it is decided as malicious node. This paper also discusses the detection of link failure due to the presence of malicious node by determining the gain of each link in the network. The performance of the proposed method is analyzed using packet delivery ratio, network life time, and throughput and energy consumption. The proposed malicious node detection system is compared with the conventional techniques as OEERP (Optimized energy efficient routing protocol), LEACH (Low energy adaptive clustering hierarchy), DRINA (Data routing for In-network aggregation) and BCDCP (Base station controlled dynamic clustering protocol).展开更多
Background:Oral cavity(OC),oropharyngeal(OP),hypopharyngeal(HP),and laryngeal(LA)squamous cell carcinoma(SCC)have a high incidence of regional lymph node metastasis(LNM).Elective irradiation for clinically node-negati...Background:Oral cavity(OC),oropharyngeal(OP),hypopharyngeal(HP),and laryngeal(LA)squamous cell carcinoma(SCC)have a high incidence of regional lymph node metastasis(LNM).Elective irradiation for clinically node-negative neck is routinely administered to treat lymph nodes harboring occult metastasis.However,the optimal elective irradiation schemes are still inconclusive.In this study,we aimed to establish individualized elective irradiation schemes for the ipsilateral and contralateral node-negative neck of these four types of cancer.Methods:From July 2005 to December 2018,793 patients with OC-SCC,464 with OP-SCC,413 with HP-SCC,and 645 with LA-SCC were recruited retrospectively.Based on the actual incidence of LNM and the tumor characteristics,risk factors for contralateral LNM,as well as node level coverage schemes for elective irradiation,were determined using logistic regression analysis.Additionally,we developed a publicly available online tool to facilitate the widespread clinical use of these schemes.Results:For the ipsilateral node-negative neck,elective irradiation at levels Ⅰ-Ⅲ for OC-SCC and levels Ⅱ-Ⅳa for OP-,HP-and LA-SCC are generally recommended.In addition,level Ⅶa should be included in patients with OPSCC.Multivariate analyses revealed that posterior hypopharyngeal wall and post-cricoid region involvement were independently associated with level Ⅶa metastasis in HP-SCC(all P<0.05).For the contralateral node-negative neck,multivariate analyses revealed that ipsilateral N2b2-N3,tumors with body midline involvement,and degree of tumor invasion were the independent factors for contralateral LNM(all P<0.05).In patients who require contralateral neck irradiation,levels Ⅰ-Ⅱ are recommended for OC-SCC,and additional level Ⅲ is recommended for patients with ipsilateral N3 disease.Levels Ⅱ-Ⅲ are recommended for OP-,HP-,and LA-SCC,and additional level Ⅳa is recommended for patients with advanced T or ipsilateralNclassifications.Furthermore,additional level Ⅶa is recommended only fo展开更多
Objective:To use the Surveillance,Epidemiology,and End Results(SEER)database to verify the findings of a recent National Cancer Database(NCDB)study that identified factors predicting occult nodal involvement in cutane...Objective:To use the Surveillance,Epidemiology,and End Results(SEER)database to verify the findings of a recent National Cancer Database(NCDB)study that identified factors predicting occult nodal involvement in cutaneous head and neck melanoma(CHNM)while identifying additional predictors of occult nodal metastasis and comparing two distinct cancer databases.Methods:Cases of CHNM in the SEER database diagnosed between 2004 and 2014 were identified.Demographic information and oncologic data were obtained.Univariate and multivariate analysis were performed to identify factors associated with pathologic nodal positivity.Results:There were 34002 patients with CHNM identified.Within this population,16232 were clinically node-negative,1090 of which were found to be pathologically node-positive.On multivariate analysis,factors associated with an increased risk of occult nodal metastasis included increasing depth of invasion(stepwise increase in adjusted odds ratio[OR]),nodular histology(aOR:1.47[95%CI:1.21-1.80]),ulceration(aOR:1.74[95%CI:1.48-2.05]),and mitoses(aOR:1.86[95%CI:1.36-2.54]).Factors associated with a decreased risk of occult nodal metastasis included female sex(aOR:0.80[0.67-0.94])and desmoplastic histology(aOR:0.37[95%CI:0.24-0.59]).Between the SEER database and the NCDB,factors associated with occult nodal involvement were similar except for nodular histology and female sex,which did not demonstrate significance in the NCDB.Conclusion:Regarding clinically node-negative CHNM,the SEER database and the NCDB have similarities in demographic information but differences in baseline population sizes and tumor characteristics that should be considered when comparing findings between the two databases.展开更多
车载自组网基于竞争的MAC协议IEEE 802.11P存在预见性、公平性、低吞吐量、延迟性、高碰撞率等问题。提出基于集群协作的MAC协议CCBM(an cooperative cluster-based MAC protocol for VANETs),解决节点接入信道的公平性问题,同时提高信...车载自组网基于竞争的MAC协议IEEE 802.11P存在预见性、公平性、低吞吐量、延迟性、高碰撞率等问题。提出基于集群协作的MAC协议CCBM(an cooperative cluster-based MAC protocol for VANETs),解决节点接入信道的公平性问题,同时提高信道的利用率和有效地适应网络拓扑变化。理论计算和仿真结果显示,选择集群头节点HN(head node)的平均时隙小于IEEE 802.11P 50%,稳定性增加50%。展开更多
文摘The power supplies of wireless sensor networks (WSNs) are not replaceable orrechargeable forsensors. For reducing the communication protocols’ impact onthe sensor network’s energy dissipation,various protocols or mechanisms havebeen proposed. Therefore, this article proposesa stable random number-basedLEACH protocol to stabilize the random number generation toimprove the CHselection efficiency. The wireless sensor network’s average node energy (ANE)ismultiplied by the random number that relies on the nodes’ energy. A nodegrade algorithm(NGA) based relay selection is introduced for inter andintracluster communication for energy efficiencyenhancement. The proposed NGA calculates the grade of a node using residual energy,distance from CHs,and its traffic parameters. Based on the simulation results, the proposedSRN-LEACH protocol shows superior performance as compared to existing protocolsincludingreduced energy dissipation, improved communication quality, andNLT. The proposed methodattains a minimum average delay of 0.136ms, 0.95% PDR, 148kbps TP rate, and 98% NLT.
文摘In Mobile Ad Hoc Networks(MANET),Quality of Service(QoS)is an important factor that must be analysed for the showing the better performance.The Node Quality-based Clustering Algorithm using Fuzzy-Fruit Fly Optimiza-tion for Cluster Head and Gateway Selection(NQCAFFFOCHGS)has the best network performance because it uses the Improved Weighted Clustering Algo-rithm(IWCA)to cluster the network and the FFO algorithm,which uses fuzzy-based network metrics to select the best CH and entryway.However,the major drawback of the fuzzy system was to appropriately select the membership func-tions.Also,the network metrics related to the path or link connectivity were not considered to effectively choose the CH and gateway.When learning fuzzy sets,this algorithm employs a new Continuous Action-set Learning Automata(CALA)approach that correctly modifies and chooses the fuzzy membership functions.Despite the fact that it extends the network’s lifespan,it does not assist in the detection of defective nodes in the routing route.Because of this,a new Fault Tolerance(NQCAEFFFOCHGS-FT)mechanism based on the Distributed Connectivity Restoration(DCR)mechanism is proposed,which allows the net-work to self-heal as a consequence of the algorithm’s self-healing capacity.Because of the way this method is designed,node failures may be utilised to rebuild the network topology via the use of cascaded node moves.Founded on the fractional network information and topologic overhead related with each node,the DCR is suggested as an alternative to the DCR.When compared to the NQCAFFFOCHGS algorithm,the recreation results display that the proposed NQCAEFFFOCHGS-FT algorithm improves network performance in terms of end-to-end delay,energy consumption,Packet Loss Ratio(PLR),Normalized Routing Overhead(NRO),and Balanced Load Index(BLI).
文摘BACKGROUND Malignant proliferating trichilemmal tumor(MPTT)is an infrequent malignant neoplasm originating from cutaneous appendages,with only a handful of documented cases.This report delineates a unique instance of MPTT situated in the neck,accompanied by lymph node metastasis.A comprehensive exposition of its clinical trajectory and imaging manifestation is presented,aiming to enhance comprehension and management of this atypical ailment.CASE SUMMARY Patient concerns:A 79-year-old male presented with a longstanding right neck mass persisting for over six decades,exhibiting recent enlargement over the past year.Diagnoses:Enhanced magnetic resonance imaging of the neck unveiled an elliptical mass on the right neck side,characterized by an ill-defined border and a heterogeneous signal pattern.The mass exhibited subdued signal intensity on T1-weighted imaging(T1WI)and a heterogeneous high signal on T2-weighted imaging(T2WI),interspersed with a lengthy T1 and T2 cystic signal motif.Close anatomical association with the submandibular gland joint was noted,and intravenous gadolinium diethylene triamine pentaacetic acid administration facilitated conspicuous enhancement.Substantial enhancement of the solid segment prompted an initial preoperative diagnosis of malignant nerve sheath tumor.However,post-surgery histopathological and immunohistochemical analysis conclusively confirmed the diagnosis as malignant hyperplastic external hair root sheath tumor.Intervention:Complete excision of the tumor was successfully executed.Outcomes:The patient experienced a favorable postoperative recovery.CONCLUSION Malignant proliferative trichilemmal tumor external hair root sheath tumor is a cystic-solid lesion,appearing as low signal on T1WI images or high signal on T2WI with enhancement of the solid component.Suspicions of malignancy are heightened when the tumor border is indistinct,tissue planes are breached,or when linear or patchy high signals are observed in the subcutaneous tissue on T1 liver acquisition with volume accelerat
基金This work was supported by the National Institutes of Health(Grant No.:R01 DE15964)(C.Y.W).
文摘Head and neck squamous cell carcinoma(HNSCC)is a highly aggressive tumor and the sixth most common cancer worldwide.Current treatment strategies for HNSCC are surgery,radiotherapy,chemotherapy,immunotherapy or combinatorial therapies.However,the overall 5-year survival rate of HNSCC patients remains at about 50%.Cancer stem cells(CSCs),a small population among tumor cells,are able to self-renew and differentiate into different tumor cell types in a hierarchical manner,similar to normal tissue.In HNSCC,CSCs are proposed to be responsible for tumor initiation,progression,metastasis,drug resistance,and recurrence.In this review,we discuss the molecular and cellular characteristics of CSCs in HNSCC.We summarize current approaches used in the literature for identification of HNSCC CSCs,and mechanisms required for CSC regulation.We also highlight the role of CSCs in treatment failure and therapeutic targeting options for eliminating CSCs in HNSCC.
文摘In the past few decades,Energy Efficiency(EE)has been a significant challenge in Wireless Sensor Networks(WSNs).WSN requires reduced transmission delay and higher throughput with high quality services,it further pays much attention in increased energy consumption to improve the network lifetime.To collect and transmit data Clustering based routing algorithm is considered as an effective way.Cluster Head(CH)acts as an essential role in network connectivity and perform data transmission and data aggregation,where the energy consumption is superior to non-CH nodes.Conventional clustering approaches attempts to cluster nodes of same size.Moreover,owing to randomly distributed node distribution,a cluster with equal nodes is not an obvious possibility to reduce the energy consumption.To resolve this issue,this paper provides a novel,Balanced-Imbalanced Cluster Algorithm(B-IBCA)with a Stabilized Boltzmann Approach(SBA)that attempts to balance the energy dissipation across uneven clusters in WSNs.B-IBCA utilizes stabilizing logic to maintain the consistency of energy consumption among sensor nodes’.So as to handle the changing topological characteristics of sensor nodes,this stability based Boltzmann estimation algorithm allocates proper radius amongst the sensor nodes.The simulation shows that the proposed B-IBCA outperforms effectually over other approaches in terms of energy efficiency,lifetime,network stability,average residual energy and so on.
文摘Mobile Ad hoc Network (MANET) is a significant concept of wireless networks which comprises of thousands of nodes that are mobile as well as autonomous and they do not requires any existing network infrastructure. The autonomous nodes can freely and randomly move within the network which can create temporary dynamic network and these networks can change their topology frequently. The security is the primary issue in MANET which degrades the network performance significantly. In this paper, cluster based malicious node detection methodology is proposed to detect and remove the malicious nodes. Each node within the cluster gets the cluster key from the cluster head and this key is used for the data transaction between cluster head and node. The cluster head checks this key for every data transaction from node and match with their cluster table. If match is valid, and then only it will recognize that this node is belongs to this cluster, otherwise it is decided as malicious node. This paper also discusses the detection of link failure due to the presence of malicious node by determining the gain of each link in the network. The performance of the proposed method is analyzed using packet delivery ratio, network life time, and throughput and energy consumption. The proposed malicious node detection system is compared with the conventional techniques as OEERP (Optimized energy efficient routing protocol), LEACH (Low energy adaptive clustering hierarchy), DRINA (Data routing for In-network aggregation) and BCDCP (Base station controlled dynamic clustering protocol).
基金supported by the National Natural Science Foundation of China[grant number 81872463 and 81930072]Special Support Program of Sun Yat-sen University Cancer Center[grant number 16zxtzlc06]+5 种基金Key-Area Research and Development Program of Guangdong Province[grant number 2019A1515012045 and 2019B020230002]Health&Medical Collaborative Innovation Project of Guangzhou City,China[grant number 201803040003]Science and Technology Program of Guangzhou,China,[grant number 201607010199]Innovation Team Development Plan of the Ministry of Education(No.IRT_17R110)Overseas Expertise Introduction Project for Discipline Innovation(111 Project,B14035)Natural Science Foundation of Guang Dong Province(No.2017A030312003).
文摘Background:Oral cavity(OC),oropharyngeal(OP),hypopharyngeal(HP),and laryngeal(LA)squamous cell carcinoma(SCC)have a high incidence of regional lymph node metastasis(LNM).Elective irradiation for clinically node-negative neck is routinely administered to treat lymph nodes harboring occult metastasis.However,the optimal elective irradiation schemes are still inconclusive.In this study,we aimed to establish individualized elective irradiation schemes for the ipsilateral and contralateral node-negative neck of these four types of cancer.Methods:From July 2005 to December 2018,793 patients with OC-SCC,464 with OP-SCC,413 with HP-SCC,and 645 with LA-SCC were recruited retrospectively.Based on the actual incidence of LNM and the tumor characteristics,risk factors for contralateral LNM,as well as node level coverage schemes for elective irradiation,were determined using logistic regression analysis.Additionally,we developed a publicly available online tool to facilitate the widespread clinical use of these schemes.Results:For the ipsilateral node-negative neck,elective irradiation at levels Ⅰ-Ⅲ for OC-SCC and levels Ⅱ-Ⅳa for OP-,HP-and LA-SCC are generally recommended.In addition,level Ⅶa should be included in patients with OPSCC.Multivariate analyses revealed that posterior hypopharyngeal wall and post-cricoid region involvement were independently associated with level Ⅶa metastasis in HP-SCC(all P<0.05).For the contralateral node-negative neck,multivariate analyses revealed that ipsilateral N2b2-N3,tumors with body midline involvement,and degree of tumor invasion were the independent factors for contralateral LNM(all P<0.05).In patients who require contralateral neck irradiation,levels Ⅰ-Ⅱ are recommended for OC-SCC,and additional level Ⅲ is recommended for patients with ipsilateral N3 disease.Levels Ⅱ-Ⅲ are recommended for OP-,HP-,and LA-SCC,and additional level Ⅳa is recommended for patients with advanced T or ipsilateralNclassifications.Furthermore,additional level Ⅶa is recommended only fo
文摘Objective:To use the Surveillance,Epidemiology,and End Results(SEER)database to verify the findings of a recent National Cancer Database(NCDB)study that identified factors predicting occult nodal involvement in cutaneous head and neck melanoma(CHNM)while identifying additional predictors of occult nodal metastasis and comparing two distinct cancer databases.Methods:Cases of CHNM in the SEER database diagnosed between 2004 and 2014 were identified.Demographic information and oncologic data were obtained.Univariate and multivariate analysis were performed to identify factors associated with pathologic nodal positivity.Results:There were 34002 patients with CHNM identified.Within this population,16232 were clinically node-negative,1090 of which were found to be pathologically node-positive.On multivariate analysis,factors associated with an increased risk of occult nodal metastasis included increasing depth of invasion(stepwise increase in adjusted odds ratio[OR]),nodular histology(aOR:1.47[95%CI:1.21-1.80]),ulceration(aOR:1.74[95%CI:1.48-2.05]),and mitoses(aOR:1.86[95%CI:1.36-2.54]).Factors associated with a decreased risk of occult nodal metastasis included female sex(aOR:0.80[0.67-0.94])and desmoplastic histology(aOR:0.37[95%CI:0.24-0.59]).Between the SEER database and the NCDB,factors associated with occult nodal involvement were similar except for nodular histology and female sex,which did not demonstrate significance in the NCDB.Conclusion:Regarding clinically node-negative CHNM,the SEER database and the NCDB have similarities in demographic information but differences in baseline population sizes and tumor characteristics that should be considered when comparing findings between the two databases.
