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Rotational Intravascular Multidirectional Ultrasound Catheter for Sonothrombolysis of Retracted Clots:An in Vitro and in Vivo Study

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Engineering 2024年第11期42卷 235-243页

作者： Huaiyu Wu Jinwook Kim Bohua Zhang Gabe Owens Greyson Stocker Mengyue Chen Benjamin C.Kreager Ashley Cornett Kathlyne Bautista Tarana Kaovasia Paul A.Dayton Zhen Xu Xiaoning Jiang Department of Mechanical and Aerospace Engineering North Carolina State UniversityRaleighNC 27695USA Joint Department of Biomedical Engineering The University of North Carolina at Chapel HillChapel HillNC 27599USA Department of Biomedical Engineering University of MichiganAnn ArborMI 48109USA

Thromboembolism in blood vessels poses a serious risk of stroke,heart attack,and even sudden death if not properly *** combined with ultrasound contrast agents has emerged as a promising approach for the effective treatment of *** reports have highlighted the potential of intravascular sonothrombolysis as a safe and effective treatment modality for deep vein thrombosis(DVT).However,its efficiency has not been validated through in vivo testing of retracted *** study aimed to develop a miniaturized multidirectional transducer featuring two 4-layer lead zir-conate titanate(PZT-5A)stacks with an aperture size of 1.4 mm1.4 mm,enabling both forward-and side-looking *** into a custom two-lumen 10-French(Fr)catheter,the capability of this device for intravascular sonothrombolysis was validated both in vitro and in *** low-dose tissue plasminogen activators and nanodroplets,the rotational multidirectional transducer reduced the retracted clot mass(800 mg)by an average of 52%within 30 min during in vitro *** lysis rate was significantly higher by 37%than that in a forward-viewing transducer without *** improvement was particularly noteworthy in the treatment of retracted ***,a long-retracted clot(>10 cm)was successfully treated within 40 min in vivo by creating a flow channel with a diameter>4 mm in a porcine DVT *** conclusion,these findings strongly suggest the potential of this technique for clinical applications in sonothrombolysis,offering a feasible solution for effectively treating thromboembolism,particularly in challenging cases involving retracted clots.

关键词： Intravascular ultrasound catheter Sonothrombolysis in vivo Retracted clots thrombolysis

Recovery of spermatogenesis following testosterone replacement therapy or anabolic-androgenic steroid use

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Asian Journal of Andrology 2016年第3期18卷 373-380,I0007页

作者： J Abram McBride Robert M Coward Department of Urology University of North Carolina School of Medicine Chapel Hill NC 27599-7235 USA.

The use of testosterone replacement therapy （TRT） for hypogonadism continues to rise, particularly in younger men who may wish to remain fertile. Concurrently, awareness of a more pervasive use of anabolic-androgenic steroids （AAS） within the general population has been appreciated. Both TRT and AAS can suppress the hypothalamic-pituitary-gonadal （HPG） axis resulting in diminution of spermatogenesis. Therefore, it is important that clinicians recognize previous TRT or AAS use in patients presenting for infertility treatment. Cessation of TRT or AAS use may result in spontaneous recovery of normal spermatogenesis in a reasonable number of patients if allowed sufficient time for recovery. However, some patients may not recover normal spermatogenesis or tolerate waiting for spontaneous recovery. In such cases, clinicians must be aware of the pathophysiologic derangements of the HPG axis related to TRT or AAS use and the pharmacologic agents available to reverse them. The available agents include injectable gonadotropins, selective estrogen receptor modulators, and aromatase inhibitors, but their off-label use is poorly described in the literature, potentially creating a knowledge gap for the clinician. Reviewing their use clinically for the treatment of hypogonadotropic hypogonadism and other HPG axis abnormalities can familiarize the clinician with the manner in which they can be used to recover spermatogenesis after TRT or AAS use.

关键词： anabolic steroids hypogonadism infertility spermatogenesis testosterone testosterone replacement therapy vasectomy reversal

Magnetic anisotropy in Fe-25Cr-12Co-1Si alloy induced by external magnetic field

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中国有色金属学会会刊：英文版 2007年第2期17卷 346-350页

作者：甄良孙学银徐成彦高润生徐仁根秦禄昌 School of Materials Science and Engineering Harbin Institute of Technology Department of Physics and Astronomy University of North Carolina at Chapel Hill

Structural and magnetic properties of Fe-25Cr-12Co-1Si alloy thermo-magnetically treated under different external magnetic field conditions were investigated. Orientation and morphology of the ferromagnetic α1 phase embedded in α2 phase matrix before and after step ageing are characterized by transmission electron microscope(TEM). The results show that the ellipsoidal particles of ferromagnetic α1 phase are aligned along the direction of external magnetic field during isothermal magnetic ageing. Approximately 28% of the total coercivity can be attributed to the shape anisotropy of α1 phase particles induced by external magnetic field for Fe-25Cr-12Co-1Si alloy thermo-magnetically treated with a parallel magnetic field.

关键词： Fe-25Cr-12Co-1Si合金磁各向异性诱导外加磁场

Reinforcement＇s incidental effects on reproductive isolation between conspecifics

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Current Zoology 2016年第2期62卷 135-143页

作者： Biology Department Daniel R. MATUTE Biology Department University of North Carolina 250 Bell Tower Road Chapel Hill NC 27599 USA

Reinforcement--the process whereby maladaptive hybridization leads to the strengthening of prezygotic isolation between species--has a long history in the study of speciation. Because reinforcement affects traits involved in mate choice and fertility, it can have indirect effects on reproductive isolation between populations within species. Here we review examples of these ＂cascading effects of reinforcement＂（CER） and discuss different mechanisms through which they can arise. We discuss three factors that are predicted to influence the potential occurrence of CER： rates of gene flow among populations, the strength of selection acting on the traits involved in reinforcement, and the genetic basis of those traits. We suggest that CER is likely if （1） the rate of gene flow between conspecific populations is low; （2） divergent selection acts on phenotypes involved in reinforcement between sympatric and allopatric populations; and （3） the genetic response to reinforcement differs among conspecific populations subject to parallel reinforcing selection. Future work continuing to address gene flow, selection, and the genetic basis of the traits involved in the reinforcement will help develop a better understanding of reinforcement as a process driving the production of species diversity, both directly and incidentally.

关键词： reinforcement speciation reproductive character displacement

Chronic gastrointestinal symptoms and quality of life in the Korean population

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World Journal of Gastroenterology 2008年第41期14卷 6388-6394页

作者： Jeong-Jo Jeong Myung-Gyu Choi Young-Seok Cho Seung-Geun Lee Jung-Hwan Oh Jae-Myung Park Yu-Kyung Cho In-Seok Lee Sang-Woo Kim Sok-Won Han Kyu-Yong Choi In-Sik Chung Department of Internal Medicine the Catholic University of Korea Department of Biostatistics University of North Carolina at Chapel Hill NC

AIM： To evaluate the prevalence of chronic gastroin- testinal symptoms and their impact on health-related quality of life （HRQOL） in the Korean population. METHODS： A cross-sectional survey, using a reliable and valid Rome I] based questionnaire, was per- formed on randomly selected residents, between 18 and 69 years in age. All respondents were interviewed at their homes or offices by a team of interviewers. The impact of chronic gastrointestinal symptoms on HRQOL was assessed using the Korean version of the 36-item Short-Form general health survey （SF-36）. RESULTS： Of the 1807 eligible subjects, 1417 （78.4%： male 762; female 655） were surveyed. Out of the respondents, 18.6% exhibited at least one chronic gastrointestinal symptom. The prevalence of gastro- esophageal reflux disease （GERD）, defined as heart- burn and/or acid regurgitation experienced at least weekly, was 3.5% （95% CI, 2.6-4.5）. The prevalence of uninvestigated dyspepsia, irritable bowel syndrome （IBS） and chronic constipation based on Rome Ⅱ criteria were 11.7% （95% CI, 10.1-13.5）, 2.2% （95% CI, 1.5-3.1）, and 2.6% （95% CI, 1.8-3.5） respectively. Compared with subjects without chronic gastrointesti- nal symptoms （n = 1153）, those with GERD （n = 50）, uninvestigated dyspepsia （n = 166） and IBS （n = 31） had significantly worse scores on most domains of the SF-36 scales. CONCLUSION： The prevalence of GERD, uninvesti- gated dyspepsia and IBS were 3.5%, 11.7% and 2.2% respectively, in the Korean population. The health- related quality of life was significantly impaired in subjects with GERD, uninvestigated dyspepsia and IBS in this community.

关键词： Chronic gastrointestinal symptom Gastroesophageal reflux disease Dyspepsia Irritable bowel syndrome Qaulibl of life

Cyanidin-3-glucoside protects the photooxidative damage of retinal pigment epithelium cells by regulating sphingolipid signaling and inhibiting MAPK pathway

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Food Science and Human Wellness 2024年第2期13卷 621-632页

作者： Tingting Liu Wentao Qi Wenting Peng Jianan Zhang Yong Wang School of Health Science and Engineering University of Shanghai for Science and TechnologyShanghai 200093China Academy of National Food and Strategic Reserves Administration Beijing 100037China Department of Chemistry University of North Carolina at Chapel HillChapel HillNC 27599USA

Cyanidin-3-glucoside(C3G)is the most common anthocyanin in dark grains and berries and is a food functional factor to improve visual ***,the mechanisms of C3G on blue light-induced retinal pigment epithelial(RPE)cell photooxidative damage needs further *** investigated the effects of C3G on blue light-irradiated A2E-containing RPE cells and explored whether sphingolipid,mitogen-activated protein kinase(MAPK),and mitochondria-mediated pathways are involved in this *** light irradiation led to mitochondria and lysosome damage in RPE cells,whereas C3G preserved mitochondrial morphology and function and maintained the lysosomal integrity.C3G suppressed the phosphorylation of JNK and p38 MAPK and mitochondria-mediated pathways to inhibit RPE cell *** data showed that C3G protected RPE cells against blue light-induced lipid peroxidation and apoptosis by maintaining sphingolipids balance.C3G significantly inhibited ceramide(Cer d18:0/15:0,Cer d18:0/16:0 and Cer d18:0/18:0)accumulation and elevated galactosylceramide(GalCer d18:1/15:0 and GalCer d18:1/16:0)levels in the irradiated A2E-containing RPE ***,C3G attenuated cell membrane damage by increasing phosphatidylcholine and phosphatidylserine levels.C3G inhibited apoptosis and preserved the structure of mitochondria and lysosome by regulating sphingolipid signaling and suppression of MAPK activation in RPE ***,dietary supplementation of C3G prevents retinal photooxidative damage.

关键词： Cyanidin-3-glucoside Ceramide MAPK pathway Mitochondria-dependent apoptosis Lipidomics analysis

Changes in forest structure, species diversity and spatial pattern following hurricane disturbance in a Piedmont North Carolina forest, USA

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Journal of Plant Ecology 2008年第1期1卷 43-57页

作者： Weimin Xi Robert K.Peet Dean L.Urban Department of Biology University of North Carolina at Chapel HillChapel HillNC 29599-3280USA The Nicholas School of the Environment and Earth Sciences Duke UniversityDurhamNC 27708USA

Aims Large hurricanes have profound impacts on temperate forests,but owing to their infrequent nature these effects have rarely been examined in *** 1996,Hurricane Fran significantly damaged many long-term tree census plots in the Duke Forest on the North Carolina Piedmont,thereby providing an exceptional opportunity to examine pre-and post-hurricane forest compositional *** goal was to examine immediate,short-term(0–4 years)and longer term(;5 year)hurricane-induced structural,spatial and compositional changes in the tree population(stem d.b.h>1 cm)in the context of our detailed,long-term knowledge of the dynamics of these *** We surveyed stem damage and tree mortality in 34 long-term permanent plots(ca.70-year record;404–1012 m^(2))and 7 large mapped tree stands(ca.20-year record;5250–65000 m^(2))representing both transition-phase,even-aged pine stands and uneven-aged upland hardwood *** employed three types of damage measures to quantify stand-level damage severity:percentage of stems damaged,percentage of basal area lost and a‘stand-level damage index’.Second-order spatial analysis(Ripley’s K-function)was used to investigate patterns in tree *** findings Our study found hurricane effects on the structural attributes of Piedmont forests to be variable and *** in tree species composition,however,were *** was the major damage type for the overstory trees[diameter at breast height(d.b.h.)>10 cm]apparently due to the exposure of the crowns to high wind combined with heavy rainfall prior to and during the ***,juvenile trees and small trees(1–10 cm d.b.h.)of the understory and midstory were mainly damaged by being pinned or bent by their damaged large ***-induced tree mortality varied weakly among species,was positively correlated with pre-hurricane tree size and remained up to 2-fold higher than pre-hurricane background mortality 5 years after the ***

关键词： delayed tree mortality disturbance ecology hurricane damage d Hurricane Fran spatial point pattern analysis stand dynamics structural heterogeneity

Statistical Inference for Partially Linear Regression Models with Measurement Errors

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Chinese Annals of Mathematics,Series B 2008年第2期29卷 207-222页

作者： Jinhong YOU Qinfeng XU Bin ZHOU Department of Biostatistics University of North Carolina at Chapel Hill Chapel-Hill NC 27599-7400 USA Corresponding author. School of Mathematical Sciences Fudan University Shanghai 200433 China Department of Statistics East China Normal University Shanghai 200062 China

In this paper,the authors investigate three aspects of statistical inference for the partially linear regression models where some covariates are measured with ***, a bandwidth selection procedure is proposed,which is a combination of the differencebased technique and GCV ***,a goodness-of-fit test procedure is proposed, which is an extension of the generalized likelihood ***,a variable selection procedure for the parametric part is provided based on the nonconcave penalization and corrected profile least *** as＂Variable selection via nonconcave penalized likelihood and its oracle properties＂（***.,96,2001,1348-1360）,it is shown that the resulting estimator has an oracle property with a proper choice of regularization parameters and penalty *** studies are conducted to illustrate the finite sample performances of the proposed procedures.

关键词： Partially linear model Measurement error Bandwidth selection Goodness-of-fit test Oracle property

Consistency of the penalized MLE for two-parameter gamma mixture models

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Science China Mathematics 2016年第12期59卷 2301-2318页

作者： CHEN JiaHua LI ShaoTing TAN XianMing Research Institute of Big Data Yunnan University Kunming 650221 China Department of Statistics University of British Columbia Vancouver VTC 5K5 Canada Department of Biostatistics University of North Carolina at Chapel Hill Chapel Hill NC 27514 USA

Two-parameter gamma distributions are widely used in liability theory, lifetime data analysis, financial statistics, and other areas. Finite mixtures of gamma distributions are their natural extensions, and they are particularly useful when the population is suspected of heterogeneity. These distributions are successfully employed in various applications, but many researchers falsely believe that the maximum likelihood estimator of the mixing distribution is consistent. Similarly to finite mixtures of normal distributions, the likelihood function under finite gamma mixtures is unbounded. Because of this, each observed value leads to a global maximum that is irrelevant to the true distribution. We apply a seemingly negligible penalty to the likelihood according to the shape parameters in the fitted model. We show that this penalty restores the consistency of the likelihoodbased estimator of the mixing distribution under finite gamma mixture models. We present simulation results to validate the consistency conclusion, and we give an example to illustrate the key points.

关键词： constrained MLE identifiability finite mixture penalized likelihood Stirling formula