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Adaptive Conditional Hazard Regression Modeling of Multiple Event Times
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作者 George J. Knafl 《Open Journal of Endocrine and Metabolic Diseases》 2023年第4期492-513,共22页
Recurrent event time data and more general multiple event time data are commonly analyzed using extensions of Cox regression, or proportional hazards regression, as used with single event time data. These methods trea... Recurrent event time data and more general multiple event time data are commonly analyzed using extensions of Cox regression, or proportional hazards regression, as used with single event time data. These methods treat covariates, either time-invariant or time-varying, as having multiplicative effects while general dependence on time is left un-estimated. An adaptive approach is formulated for analyzing multiple event time data. Conditional hazard rates are modeled in terms of dependence on both time and covariates using fractional polynomials restricted so that the conditional hazard rates are positive-valued and so that excess time probability functions (generalizing survival functions for single event times) are decreasing. Maximum likelihood is used to estimate parameters adjusting for right censored event times. Likelihood cross-validation (LCV) scores are used to compare models. Adaptive searches through alternate conditional hazard rate models are controlled by LCV scores combined with tolerance parameters. These searches identify effective models for the underlying multiple event time data. Conditional hazard regression is demonstrated using data on times between tumor recurrence for bladder cancer patients. Analyses of theory-based models for these data using extensions of Cox regression provide conflicting results on effects to treatment group and the initial number of tumors. On the other hand, fractional polynomial analyses of these theory-based models provide consistent results identifying significant effects to treatment group and initial number of tumors using both model-based and robust empirical tests. Adaptive analyses further identify distinct moderation by group of the effect of tumor order and an additive effect to group after controlling for nonlinear effects to initial number of tumors and tumor order. Results of example analyses indicate that adaptive conditional hazard rate modeling can generate useful insights into multiple event time data. 展开更多
关键词 Adaptive Regression Fractional Polynomials Hazard Rate multiple Event times Recurrent Events
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Adaptive Conditional Hazard Regression Modeling of Multiple Event Times
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作者 George J. Knafl 《Open Journal of Statistics》 2023年第4期492-513,共22页
Recurrent event time data and more general multiple event time data are commonly analyzed using extensions of Cox regression, or proportional hazards regression, as used with single event time data. These methods trea... Recurrent event time data and more general multiple event time data are commonly analyzed using extensions of Cox regression, or proportional hazards regression, as used with single event time data. These methods treat covariates, either time-invariant or time-varying, as having multiplicative effects while general dependence on time is left un-estimated. An adaptive approach is formulated for analyzing multiple event time data. Conditional hazard rates are modeled in terms of dependence on both time and covariates using fractional polynomials restricted so that the conditional hazard rates are positive-valued and so that excess time probability functions (generalizing survival functions for single event times) are decreasing. Maximum likelihood is used to estimate parameters adjusting for right censored event times. Likelihood cross-validation (LCV) scores are used to compare models. Adaptive searches through alternate conditional hazard rate models are controlled by LCV scores combined with tolerance parameters. These searches identify effective models for the underlying multiple event time data. Conditional hazard regression is demonstrated using data on times between tumor recurrence for bladder cancer patients. Analyses of theory-based models for these data using extensions of Cox regression provide conflicting results on effects to treatment group and the initial number of tumors. On the other hand, fractional polynomial analyses of these theory-based models provide consistent results identifying significant effects to treatment group and initial number of tumors using both model-based and robust empirical tests. Adaptive analyses further identify distinct moderation by group of the effect of tumor order and an additive effect to group after controlling for nonlinear effects to initial number of tumors and tumor order. Results of example analyses indicate that adaptive conditional hazard rate modeling can generate useful insights into multiple event time data. 展开更多
关键词 Adaptive Regression Fractional Polynomials Hazard Rate multiple Event times Recurrent Events
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The Additive-multiplicative Hazards Model for Multiple Type of Recurrent Gap Times
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作者 Zhang Qi-xian Liu Ji-cai +1 位作者 Guan Qiang Wang De-hui 《Communications in Mathematical Research》 CSCD 2015年第2期97-107,共11页
Recurrent event gap times data frequently arise in biomedical studies and often more than one type of event is of interest. To evaluate the effects of covariates on the marginal recurrent event hazards functions, ther... Recurrent event gap times data frequently arise in biomedical studies and often more than one type of event is of interest. To evaluate the effects of covariates on the marginal recurrent event hazards functions, there exist two types of hazards models: the multiplicative hazards model and the additive hazards model. In the paper, we propose a more flexible additive-multiplicative hazards model for multiple type of recurrent gap times data, wherein some covariates are assumed to be additive while others are multiplicative. An estimating equation approach is presented to estimate the regression parameters. We establish asymptotic properties of the proposed estimators. 展开更多
关键词 additive-multiplicative hazards model estimating equation gap time multiple recurrent event data semi-parametric regression model
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Parametric and Non-Parametric Analysis of the Survival Times of Patients with Multiple Myeloma Cancer 被引量:1
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作者 Lohuwa Mamudu Chris P. Tsokos 《Open Journal of Applied Sciences》 2020年第4期118-134,共17页
Multiple myeloma (MM) is a type of cancer that remains incurable. In the last decade, most research into MM has focused on investigating the improvement in the therapeutic strategy. Our study assesses the survival pro... Multiple myeloma (MM) is a type of cancer that remains incurable. In the last decade, most research into MM has focused on investigating the improvement in the therapeutic strategy. Our study assesses the survival probability of 48 patients diagnosed with MM based on parametric and non-parametric techniques. We performed parametric survival analysis and found a well-def- ined probability distribution of the survival time to follow three-parameter lognormal. We then estimated the survival probability and compared it with the commonly used non-parametric Kaplan-Meier survival analysis of the survival times. The comparison of the survival probability estimates of the two methods revealed a better survival probability estimate by the parametric method than the Kaplan-Meier. The parametric survival analysis is more robust and efficient because it is based on a well-defined parametric probabilistic distribution, hence preferred over the non-parametric Kaplan-Meier. This study offers therapeutic significance for further enhancement in the treatment strategy of multiple myeloma cancer. 展开更多
关键词 multiple MYELOMA CANCER Three-Parameter LOGNORMAL Kaplan-Meier Maximum LIKELIHOOD Estimation Health Science
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Development of mutants with varying flowering times by targeted editing of multiple SVP gene copies in Brassica napus L. 被引量:3
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作者 Sunny Ahmar Yungu Zhai +8 位作者 Huibin Huang Kaidi Yu Muhammad Hafeez Ullah Khan Muhammad Shahid Rana Abdul Samad Shahid Ullah Khan Olalekan Amoo Chuchuan Fan Yongming Zhou 《The Crop Journal》 SCIE CSCD 2022年第1期67-74,共8页
Manipulation of flowering time to develop cultivars with desired maturity dates is fundamental in plant breeding.It is desirable to generate polyploid rapeseed(Brassica napus L.)germplasm with varying flowering time c... Manipulation of flowering time to develop cultivars with desired maturity dates is fundamental in plant breeding.It is desirable to generate polyploid rapeseed(Brassica napus L.)germplasm with varying flowering time controlled by a few genes.In the present study,Bna SVP,a rapeseed homolog of the Arabidopsis SVP(Short Vegetative Phase)gene,was characterized and a set of mutants was developed using a CRISPR/Cas9-based gene-editing tool.A single construct targeting multiple sites was successfully applied to precisely mutate four copies of Bna SVP.The induced mutations in these copies were stably transmitted to subsequent generations.Homozygous mutants with loss-of-function alleles and free transgenic elements were generated across the four Bna SVP homologs.All mutant T_(1)lines tested in two environments(summer and winter growing seasons)showed early-flowering phenotypes.The decrease in flowering time was correlated with the number of mutated Bna SVP alleles.The quadruple mutants showed the shortest flowering time,with a mean decrease of 40.6%–50.7%in length relative to the wild type under the two growth conditions.Our study demonstrates the quantitative involvement of Bna SVP copies in the regulation of flowering time and provides valuable resources for rapeseed breeding. 展开更多
关键词 Brassica napus Flowering time BnaSVP Gene editing
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Infiltration by monocytes of the central nervous system and its role in multiple sclerosis: reflections on therapeutic strategies
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作者 Guangyong Zhang Qing Yao +9 位作者 Chubing Long Pengcheng Yi Jiali Song Luojia Wu Wei Wan Xiuqin Rao Yue Lin Gen Wei Jun Ying Fuzhou Hua 《Neural Regeneration Research》 SCIE CAS 2025年第3期779-793,共15页
Mononuclear macrophage infiltration in the central nervous system is a prominent feature of neuroinflammation. Recent studies on the pathogenesis and progression of multiple sclerosis have highlighted the multiple rol... Mononuclear macrophage infiltration in the central nervous system is a prominent feature of neuroinflammation. Recent studies on the pathogenesis and progression of multiple sclerosis have highlighted the multiple roles of mononuclear macrophages in the neuroinflammatory process. Monocytes play a significant role in neuroinflammation, and managing neuroinflammation by manipulating peripheral monocytes stands out as an effective strategy for the treatment of multiple sclerosis, leading to improved patient outcomes. This review outlines the steps involved in the entry of myeloid monocytes into the central nervous system that are targets for effective intervention: the activation of bone marrow hematopoiesis, migration of monocytes in the blood, and penetration of the blood–brain barrier by monocytes. Finally, we summarize the different monocyte subpopulations and their effects on the central nervous system based on phenotypic differences. As activated microglia resemble monocyte-derived macrophages, it is important to accurately identify the role of monocyte-derived macrophages in disease. Depending on the roles played by monocyte-derived macrophages at different stages of the disease, several of these processes can be interrupted to limit neuroinflammation and improve patient prognosis. Here, we discuss possible strategies to target monocytes in neurological diseases, focusing on three key aspects of monocyte infiltration into the central nervous system, to provide new ideas for the treatment of neurodegenerative diseases. 展开更多
关键词 blood–brain barrier MACROPHAGES MONOCYTES multiple sclerosis NEUROINFLAMMATION review therapy
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Clinical features and possible pathogenesis of multiple evanescent white dot syndrome with different retinal diseases and events:a narrative review
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作者 Chun-Li Chen Yi-Zhe Cheng +2 位作者 Zhi-Han Zhang Ge Wang Xiao-Yan Peng 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第3期583-595,共13页
●Multiple evanescent white dot syndrome(MEWDS)is a rare fundus disease,characterized by acute vision loss and visual field defects.Many previous studies have explained the possible pathogenesis and clinical features ... ●Multiple evanescent white dot syndrome(MEWDS)is a rare fundus disease,characterized by acute vision loss and visual field defects.Many previous studies have explained the possible pathogenesis and clinical features of primary MEWDS.However,as the number of reported cases increases,secondary MEWDS occurs in other related retinal diseases and injuries,exhibiting some special characteristics.The associated retinal diseases include multifocal choroiditis/punctate inner choroidopathy(MFC/PIC),acute zonal occult outer retinopathy,best vitelliform macular dystrophy,pseudoxanthoma elasticum,and ocular toxoplasmosis.The related retinal injury is laser photocoagulation,surgery,and trauma.Although primary MEWDS often have a self-limiting course,secondary MEWDS may require treatment in some cases,according to the severity of concomitant diseases and complications.Notably,MEWDS secondary to MFC/PIC that is prone to forming choroidal neovascularization and focal choroidal excavation,needs positive treatment with corticosteroids.The possible underlying pathogenesis of secondary MEWDS is the exposure of choroidal antigen after the disruption of Bruch’s membrane.The MEWDS-related features in secondary MEWDS are still evanescent under most circumstances.Its prognosis and treatment depend on the severity of complications.Current studies propose that the etiology is associated with immune factors,including viral infection,inflammation in choroid and Bruch’s membrane,and antigen exposure caused by retinal and/or choroidal insults.More pathogenic studies should be conducted in the future.Accurate diagnosis for secondary MEWDS could benefit patients in aspects of management and prognosis. 展开更多
关键词 multiple evanescent white dot syndrome punctate inner choroidopathy multifocal choroiditis secondary multiple evanescent white dot syndrome
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Fatal multiple acyl-CoA dehydrogenase deficiency caused by ETFDH gene mutation:A case report
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作者 Xue-Xia Li Xiao-Nan Yang +1 位作者 Hu-Dan Pan Liang Liu 《World Journal of Clinical Cases》 SCIE 2024年第23期5422-5430,共9页
BACKGROUND Multiple acyl-CoA dehydrogenase deficiency(MADD)is a disease of rare autosomal recessive disorder.There are three types of MADD.Type I is a neonatalonset form with congenital anomalies.Type II is a neonatal... BACKGROUND Multiple acyl-CoA dehydrogenase deficiency(MADD)is a disease of rare autosomal recessive disorder.There are three types of MADD.Type I is a neonatalonset form with congenital anomalies.Type II is a neonatal-onset form without congenital anomalies.Type III is considered to a milder form and usually responds to riboflavin.However,late-onset form could also be fatal and not responsive to treatments.CASE SUMMARY We report a severe case of a young man with onset type III MADD induced by drugs and strenuous exercise characterized by rhabdomyolysis and liver dysfunction.Urine analysis indicated 12 out of 70 kinds of organic acids like glutaric acid-2 were detected.Serum analysis in genetic metabolic diseases revealed 24 out of 43 tested items were abnormal,revealing the elevation of several acylcarnitines and the reduction of carnitine in the patient.By next generation sequencing technology for gene sequencing related to fatty acid oxidation and carnitine cycle defects,a rare ETFDH gene variant was identified:NM_004453:4:C.1448C>T(p.Pro483 Leu).The patient was diagnosed with lateonset GAII.He was not responsive to riboflavin and progressively worsened into multiple organ failure that finally led to death.CONCLUSION Type III MADD can also be fatal and not responsive to treatments. 展开更多
关键词 Electron transfer flavoprotein dehydrogenase mutation multiple acyl-CoA dehydrogenase deficiency multiple organ failure Case report
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Design Framework of Unsourced Multiple Access for 6G Massive IoT
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作者 Chunlin Yan Siying Lyu +2 位作者 Sen Wang Yuhong Huang Xiaodong Xu 《China Communications》 SCIE CSCD 2024年第1期1-12,共12页
In this paper,ambient IoT is used as a typical use case of massive connections for the sixth generation(6G)mobile communications where we derive the performance requirements to facilitate the evaluation of technical s... In this paper,ambient IoT is used as a typical use case of massive connections for the sixth generation(6G)mobile communications where we derive the performance requirements to facilitate the evaluation of technical solutions.A rather complete design of unsourced multiple access is proposed in which two key parts:a compressed sensing module for active user detection,and a sparse interleaver-division multiple access(SIDMA)module are simulated side by side on a same platform at balanced signal to noise ratio(SNR)operating points.With a proper combination of compressed sensing matrix,a convolutional encoder,receiver algorithms,the simulated performance results appear superior to the state-of-the-art benchmark,yet with relatively less complicated processing. 展开更多
关键词 channel coding compressed sensing massive Internet-of-Things(IoT) sparse interleaverdivision multiple access(SIDMA) the sixth generation(6G)mobile communications unsourced multiple access
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Gut flora in multiple sclerosis:implications for pathogenesis and treatment 被引量:2
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作者 Weiwei Zhang Ying Wang +2 位作者 Mingqin Zhu Kangding Liu Hong-Liang Zhang 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第7期1480-1488,共9页
Multiple sclerosis is an inflammatory disorder chara cterized by inflammation,demyelination,and neurodegeneration in the central nervous system.Although current first-line therapies can help manage symptoms and slow d... Multiple sclerosis is an inflammatory disorder chara cterized by inflammation,demyelination,and neurodegeneration in the central nervous system.Although current first-line therapies can help manage symptoms and slow down disease progression,there is no cure for multiple sclerosis.The gut-brain axis refers to complex communications between the gut flo ra and the immune,nervous,and endocrine systems,which bridges the functions of the gut and the brain.Disruptions in the gut flora,termed dys biosis,can lead to systemic inflammation,leaky gut syndrome,and increased susceptibility to infections.The pathogenesis of multiple sclerosis involves a combination of genetic and environmental factors,and gut flora may play a pivotal role in regulating immune responses related to multiple scle rosis.To develop more effective therapies for multiple scle rosis,we should further uncover the disease processes involved in multiple sclerosis and gain a better understanding of the gut-brain axis.This review provides an overview of the role of the gut flora in multiple scle rosis. 展开更多
关键词 gut flora gut-brain axis multiple sclerosis PATHOGENESIS treatment
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A Review on Vibration Control of Multiple Cylinders Subjected to FlowInduced Vibrations 被引量:1
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作者 XU Wan-hai MA Ye-xuan 《China Ocean Engineering》 SCIE EI CSCD 2024年第2期183-197,共15页
The fatigue damage caused by flow-induced vibration(FIV)is one of the major concerns for multiple cylindrical structures in many engineering applications.The FIV suppression is of great importance for the security of ... The fatigue damage caused by flow-induced vibration(FIV)is one of the major concerns for multiple cylindrical structures in many engineering applications.The FIV suppression is of great importance for the security of many cylindrical structures.Many active and passive control methods have been employed for the vibration suppression of an isolated cylinder undergoing vortex-induced vibrations(VIV).The FIV suppression methods are mainly extended to the multiple cylinders from the vibration control of the isolated cylinder.Due to the mutual interference between the multiple cylinders,the FIV mechanism is more complex than the VIV mechanism,which makes a great challenge for the FIV suppression.Some efforts have been devoted to vibration suppression of multiple cylinder systems undergoing FIV over the past two decades.The control methods,such as helical strakes,splitter plates,control rods and flexible sheets,are not always effective,depending on many influence factors,such as the spacing ratio,the arrangement geometrical shape,the flow velocity and the parameters of the vibration control devices.The FIV response,hydrodynamic features and wake patterns of the multiple cylinders equipped with vibration control devices are reviewed and summarized.The FIV suppression efficiency of the vibration control methods are analyzed and compared considering different influence factors.Further research on the FIV suppression of multiple cylinders is suggested to provide insight for the development of FIV control methods and promote engineering applications of FIV control methods. 展开更多
关键词 flow-induced vibration vibration control multiple cylinders TANDEM side-by-side staggered
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Linear paired electrolysis of furfural to furoic acid at both anode and cathode in a multiple redox mediated system 被引量:1
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作者 Xinxin Li Linchuan Cong +4 位作者 Haibo Lin Fangbing Liu Xiangxue Fu Hai-Chao Xu Nan Lin 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第1期104-113,共10页
Implementing a new energy-saving electrochemical synthesis system with high commercial value is a strategy of the sustainable development for upgrading the bulk chemicals preparation technology in the future.Here,we r... Implementing a new energy-saving electrochemical synthesis system with high commercial value is a strategy of the sustainable development for upgrading the bulk chemicals preparation technology in the future.Here,we report a multiple redox-mediated linear paired electrolysis system,combining the hydrogen peroxide mediated cathode process with the I2 mediated anode process,and realize the conversion of furfural to furoic acid in both side of the dividedflow cell simultaneously.By reasonably controlling the cathode potential,the undesired water splitting reaction and furfural reduction side reactions are avoided.Under the galvanostatic electrolysis,the two-mediated electrode processes have good compatibility,which reduce the energy consumption by about 22%while improving the electronic efficiency by about 125%.This system provides a green electrochemical synthesis route with commercial prospects. 展开更多
关键词 multiple redox mediated system Linear paired electrolysis FURFURAL Furoic acid
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Early detection of multiple endocrine neoplasia type 1: A case report 被引量:1
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作者 Jie-Hao Yuan Su Luo +1 位作者 Ding-Guo Zhang Li-Sheng Wang 《World Journal of Gastroenterology》 SCIE CAS 2024年第26期3247-3252,共6页
BACKGROUND Multiple endocrine neoplasias(MENs)are a group of hereditary diseases invol-ving multiple endocrine glands,and their prevalence is low.MEN type 1(MEN1)has diverse clinical manifestations,mainly involving th... BACKGROUND Multiple endocrine neoplasias(MENs)are a group of hereditary diseases invol-ving multiple endocrine glands,and their prevalence is low.MEN type 1(MEN1)has diverse clinical manifestations,mainly involving the parathyroid glands,gastrointestinal tract,pancreas and pituitary gland,making it easy to miss the clinical diagnosis.CASE SUMMARY We present the case of a patient in whom MEN1 was detected early.A middle-aged male with recurrent abdominal pain and diarrhea was admitted to the hos-pital.Blood tests at admission revealed hypercalcemia and hypophosphatemia,and emission computed tomography of the parathyroid glands revealed a hy-perfunctioning parathyroid lesion.Gastroscopy findings suggested a duodenal bulge and ulceration.Ultrasound endoscopy revealed a hypoechoic lesion in the duodenal bulb.Further blood tests revealed elevated levels of serum gastrin.Surgery was performed,and pathological analysis of the surgical specimens revealed a parathyroid adenoma after parathyroidectomy and a neuroendocrine tumor after duodenal bulbectomy.The time from onset to the definitive diagnosis of MEN1 was only approximately 1 year.CONCLUSION For patients who present with gastrointestinal symptoms accompanied by hyper-calcemia and hypophosphatemia,clinicians need to be alert to the possibility of MEN1. 展开更多
关键词 multiple endocrine neoplasia type 1 Gastrointestinal symptoms Hypercal-cemia Early detection Case report
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C634Y mutation in RET-induced multiple endocrine neoplasia type 2A:A case report 被引量:1
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作者 Hui-Fen Zhang Shu-Ling Huang +3 位作者 Wen-Li Wang Yu-Qing Zhou Jun Jiang Zhuo-Jin Dai 《World Journal of Clinical Cases》 SCIE 2024年第15期2627-2635,共9页
BACKGROUND Multiple endocrine neoplasia type 2(MEN2)is a rare,autosomal dominant endocrine disease.Currently,the RET proto-oncogene is the only gene implicated in MEN2A pathogenesis.Once an RET carrier is detected,fam... BACKGROUND Multiple endocrine neoplasia type 2(MEN2)is a rare,autosomal dominant endocrine disease.Currently,the RET proto-oncogene is the only gene implicated in MEN2A pathogenesis.Once an RET carrier is detected,family members should be screened to enable early detection of medullary thyroid carcinoma,pheochromocytoma,and hyperparatitity.Among these,medullary thyroid carcinoma is the main factor responsible for patient mortality.Accordingly,delineating strategies to inform clinical follow-up and treatment plans based on genes is paramount for clinical practitioners.CASE SUMMARY Herein,we present RET proto-oncogene mutations,clinical characteristics,and treatment strategies in a family with MEN2A.A family study was conducted on patients diagnosed with MEN2A.DNA was extracted from the peripheral blood of family members,and first-generation exon sequencing of the RET protooncogene was conducted.The C634Y mutation was identified in three family members spanning three generations.Two patients were sequentially diagnosed with pheochromocytomas and bilateral medullary thyroid carcinomas.A 9-yearold child harboring the gene mutation was diagnosed with medullary thyroid carcinoma.Surgical resection of the tumors was performed.All family members were advised to undergo complete genetic testing related to the C634Y mutation,and the corresponding treatments administered based on test results and associated clinical guidelines.CONCLUSION Advancements in MEN2A research are important for familial management,assessment of medullary thyroid cancer invasive risk,and deciding surgical timing. 展开更多
关键词 multiple endocrine neoplasia type 2A MUTATION RET proto-oncogene Medullary thyroid carcinoma PHEOCHROMOCYTOMA Case report
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In situ formation of multiple catalysts for enhancing the hydrogen storage of MgH_(2) by adding porous Ni_(3)ZnC_(0.7)/Ni loaded carbon nanotubes microspheres 被引量:2
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作者 Bing Zhang Xiubo Xie +6 位作者 Yukun Wang Chuanxin Hou Xueqin Sun Yuping Zhang Xiaoyang Yang Ronghai Yu Wei Du 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第3期1227-1238,共12页
MgH_(2) is considered one of the most promising hydrogen storage materials because of its safety,high efficiency,high hydrogen storage quantity and low cost characteristics.But some shortcomings are still existed:high... MgH_(2) is considered one of the most promising hydrogen storage materials because of its safety,high efficiency,high hydrogen storage quantity and low cost characteristics.But some shortcomings are still existed:high operating temperature and poor hydrogen absorption dynamics,which limit its application.Porous Ni_(3)ZnC_(0.7)/Ni loaded carbon nanotubes microspheres(NZC/Ni@CNT)is prepared by facile filtration and calcination method.Then the different amount of NZC/Ni@CNT(2.5,5.0 and 7.5 wt%)is added to the MgH_(2) by ball milling.Among the three samples with different amount of NZC/Ni@CNT(2.5,5.0 and 7.5 wt%),the MgH_(2)-5 wt%NZC/Ni@CNT composite exhibits the best hydrogen storage performances.After testing,the MgH_(2)-5 wt%NZC/Ni@CNT begins to release hydrogen at around 110℃ and hydrogen absorption capacity reaches 2.34 wt%H_(2) at 80℃ within 60 min.Moreover,the composite can release about 5.36 wt%H_(2) at 300℃.In addition,hydrogen absorption and desorption activation energies of the MgH_(2)-5 wt%NZC/Ni@CNT composite are reduced to 37.28 and 84.22 KJ/mol H_(2),respectively.The in situ generated Mg_(2)NiH_(4)/Mg_(2)Ni can serve as a"hydrogen pump"that plays the main role in providing more activation sites and hydrogen diffusion channels which promotes H_(2) dissociation during hydrogen absorption process.In addition,the evenly dispersed Zn and MgZn2 in Mg and MgH_(2) could provide sites for Mg/MgH_(2) nucleation and hydrogen diffusion channel.This attempt clearly proved that the bimetallic carbide Ni_(3)ZnC_(0.7) is a effective additive for the hydrogen storage performances modification of MgH_(2),and the facile synthesis of the Ni_(3)ZnC_(0.7)/Ni@CNT can provide directions of better designing high performance carbide catalysts for improving MgH_(2). 展开更多
关键词 Mg-based hydrogen storage material Ni_(3)ZnC_(0.7)/Ni@CNT particles Ni loaded carbon nanotubes multiple catalysts.
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Optimal Multi-Timescale Scheduling of Integrated Energy Systems with Hybrid Energy Storage System Based on Lyapunov Optimization
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作者 Yehui Ma Dong Han Zhuoxin Lu 《Journal of Beijing Institute of Technology》 EI CAS 2024年第5期465-480,共16页
The economic operation of integrated energy system(IES)faces new challenges such as multi-timescale characteristics of heterogeneous energy sources,and cooperative operation of hybrid energy storage system(HESS).To th... The economic operation of integrated energy system(IES)faces new challenges such as multi-timescale characteristics of heterogeneous energy sources,and cooperative operation of hybrid energy storage system(HESS).To this end,this paper investigates the multi-timescale rolling opti-mization problem for IES integrated with HESS.Firstly,the architecture of IES with HESS is established,a comparative analysis is conducted to evaluate the advantages of the HESS over a single energy storage system(SESS)in stabilizing power fluctuations.Secondly,the dayahead and real-time scheduling cost functions of IES are established,the day-ahead scheduling mainly depends on operation costs of the components in IES,the real-time optimal scheduling adopts the Lya-punov optimization method to schedule the battery and hydrogen energy storage in each time slot,so as to minimize the real-time average scheduling operation cost,and the problem of day-ahead and real-time scheduling error,which caused by the uncertainty of the energy storage is solved by online optimization.Finally,the proposed model is verified to reduce the scheduling operation cost and the dispatching error by performing an arithmetic example analysis of the IES in Shanghai,which provides a reference for the safe and stable operation of the IES. 展开更多
关键词 integrated energy systems multiple time scales hybrid energy storage systems Lya-punov optimization
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The Extended Hybrid Carrier-Based Multiple Access Technology for High Mobility Scenarios 被引量:1
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作者 Ge Song Xiaojie Fang Xuejun Sha 《China Communications》 SCIE CSCD 2024年第1期53-68,共16页
The hybrid carrier(HC)system rooted in the carrier fusion concept is gradually garnering attention.In this paper,we study the extended hybrid carrier(EHC)multiple access scheme to ensure reliable wireless communicatio... The hybrid carrier(HC)system rooted in the carrier fusion concept is gradually garnering attention.In this paper,we study the extended hybrid carrier(EHC)multiple access scheme to ensure reliable wireless communication.By employing the EHC modulation,a power layered multiplexing framework is realized,which exhibits enhanced interference suppression capability owing to the more uniform energy distribution design.The implementation method and advantage mechanism are explicated respectively for the uplink and downlink,and the performance analysis under varying channel conditions is provided.In addition,considering the connectivity demand,we explore the non-orthogonal multiple access(NOMA)method of the EHC system and develop the EHC sparse code multiple access scheme.The proposed scheme melds the energy spread superiority of EHC with the access capacity of NOMA,facilitating superior support for massive connectivity in high mobility environments.Simulation results have verified the feasibility and advantages of the proposed scheme.Compared with existing HC multiple access schemes,the proposed scheme exhibits robust bit error rate performance and can better guarantee multiple access performance in complex scenarios of nextgeneration communications. 展开更多
关键词 extended hybrid carrier system high mo-Received:Jun.09 2023 Revised:Nov.20 2023 Editor:Yuanwei Liu bility communications multiple access
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Multiple factors influencing high-purity indium electrolytic refining
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作者 Hong-Qiang Fan Fei Li +5 位作者 Hong-Xing Zheng Wu-ji Pan Mei-Zhen Wu Yashar Behnamian Ju-Bo Peng Dong-Hai Lin 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第7期148-160,共13页
The effects of various contaminants in the electrolytic refinement of indium were investigated using a glow discharge mass spectrometer(GDMS).The effects of several factors such as the indium ion(In3+)concentration,th... The effects of various contaminants in the electrolytic refinement of indium were investigated using a glow discharge mass spectrometer(GDMS).The effects of several factors such as the indium ion(In3+)concentration,the sodium chloride(NaCl)concentration,the current density,the gelatin concentration,the pH,and the electrode distance,were examined.Significant variations in impurity levels concerning gelatin concentration were observed.Both the gelatin and In3+concentration were moderately positively correlated with the Pb content.The Sb concentration was associated positively with the NaCl concentration,while the Ti concentration had an adverse correlation with the NaCl concentration.The Bi element content was positively linked to the electrode distance.As the current density increased,Cu,Pb,and Bi impurities initially rose and then eventually declined.Notably,a critical current density of 45 A·m^(-2) was identified in this behavior. 展开更多
关键词 High-purity indium ELECTROLYSIS multiple factors ELECTROCHEMISTRY Purification
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Infection in Multiple Myeloma: Microbiological Profile and Prognosis in Senegalese Patients
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作者 Seynabou Fall El Hadj Daouda Niang +6 位作者 Khadim Sarr Lolita Mariéme Camara-Tall Modou Moustapha Ciss Amy Thiam Aminata Dakono Awa Ndiaye Fatou Samba Diago Ndiaye 《Open Journal of Blood Diseases》 2024年第2期47-58,共12页
Introduction: Infections are additional factors of morbidity and mortality in multiple myeloma (MM), and the current recommendation is antibiotic prophylaxis. In sub-Saharan Africa, few data on infectious complication... Introduction: Infections are additional factors of morbidity and mortality in multiple myeloma (MM), and the current recommendation is antibiotic prophylaxis. In sub-Saharan Africa, few data on infectious complications of MM are available. We aim to describe the microbiological features of infections in MM, and their impact on survival in Senegalese patients. Methods: A retrospective (January 2005-January 2022), analytic, multicenter study on infections in patients followed for MM (IMWG criteria) in Senegalese clinical hematology services. The socio-epidemiological, diagnostic, microbiological, evolutionary and survival aspects were analyzed. Results: The study included 106 patients with multiple myeloma who had an infection at admission or during the treatment. Ten patients have the comorbidity (hypertension, lupus, type 2 diabetes). These patients had 136 infectious events identified at diagnosis (79.2%) or during chemotherapy (20.8%). The sites of infection are lung (42.6%), urinary (29.4%), dermatological (6.6%), digestive (5.2%), osteoarticular (4.4%), ear, nose and throat (3.7%), central nervous system (1.5%), or without site. We recorded 26.4% of patients with multi-site infections. The causal pathogens are bacteria (Gram-negative bacilli: 22.1%;Gram positive bacilli: 9.5%, Mycobacterium tuberculosis: 13.3%), parasitique (plasmodium falciparum 6.6%), viruses (SARS-COV2: 2.9%, VZV: 2.2%) and fungal (2.9%). Survival was reduced in patients who had an infection at the time of multiple myeloma diagnosis (p: 0.189) and those who had multiple infectious foci (p: 0.011). Conclusion: Infections in multiple myeloma are more frequent at diagnosis. The germs are varied and mostly bacteria, particularly gram-negative bacteria, and Kochs bacillus. Our study reveals that multiple infectious foci are a poor prognosis factor. It is necessary to evaluate the infectious risk early, and to adopt an antibiotic prophylaxis based on our tropical environment. 展开更多
关键词 multiple Myeloma INFECTIONS TUBERCULOSIS Senegal
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Three-dimensional magnetic reconnection in complex multiple X-point configurations in an ancient solar-lunar terrestrial system
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作者 何向磊 毛傲华 +2 位作者 孙萌萌 邹继同 王晓钢 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期488-495,共8页
Magnetic reconnection processes in three-dimensional(3D)complex field configurations have been investigated in different magneto-plasma systems in space,laboratory,and astrophysical systems.Two-dimensional(2D)features... Magnetic reconnection processes in three-dimensional(3D)complex field configurations have been investigated in different magneto-plasma systems in space,laboratory,and astrophysical systems.Two-dimensional(2D)features of magnetic reconnection have been well developed and applied successfully to systems with symmetrical property,such as toroidal fusion plasmas and laboratory experiments with an axial symmetry.But in asymmetric systems,the 3D features are inevitably different from those in the 2D case.Magnetic reconnection structures in multiple celestial body systems,particularly star-planet-Moon systems,bring fresh insights to the understanding of the 3D geometry of reconnection.Thus,we take magnetic reconnection in an ancient solar-lunar terrestrial magneto-plasma system as an example by using its crucial parameters approximately estimated already and also some specific applications in pathways for energy and matter transports among Earth,ancient Moon,and the interplanetary magnetic field(IMF).Then,magnetic reconnection of the ancient lunar-terrestrial magnetospheres with the IMF is investigated numerically in this work.In a 3D simulation for the Earth-Moon-IMF system,topological features of complex magnetic reconnection configurations and dynamical characteristics of magnetic reconnection processes are studied.It is found that a coupled lunar-terrestrial magnetosphere is formed,and under various IMF orientations,multiple X-points emerge at distinct locations,showing three typical magnetic reconnection structures in such a geometry,i.e.,the X-line,the triple current sheets,and the A-B null pairs.The results can conduce to further understanding of reconnection physics in 3D for plasmas in complex magnetic configurations,and also a possible mechanism for energy and matters transport in evolutions of similar astrophysical systems. 展开更多
关键词 magnetic reconnection multiple X-points complex magneto-plasma system
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