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Functional magnetic resonance imaging in an animal model of pancreatic cancer

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World Journal of Gastroenterology 2010年第26期16卷 3292-3298页

作者： Robert J Lewandowski aaron C Eifler David J Bentrem Johnathan C Chung Gayle E Woloschak Robert Ryu Riad Salem Andrew C Larson Reed A Omary Department of Radiology Northwestern University Feinberg School of Medicine Chicago IL 60611 United States Department of Surgical Oncology Northwestern University Feinberg School of Medicine Chicago IL 60611 United States Department of Radiation Oncology Northwestern University Feinberg School of Medicine Chicago IL 60611 United States

AIm: To test the hypotheses that diffusion weighed (DW)and transcatheter intraarterial perfusion (TRIP)magnetic resonance imaging (mRI) can each be used to assess regional differences in tumor function in an animal pancreatic cancer ***: VX2 tumors were implanted in pancreata of 6 rabbits. mRI and digital subtraction angiography (DSA) were performed 3 wk following implantation. With a 2-French catheter secured in the rabbit's gastroduodenal artery, each rabbit was transferred to an adjacent 1.5T mRI scanner. DWand TRIP-mRI were performed to determine if necrotic tumor core could be differentiated from viable tumor periphery. For each, we compared mean differences between tumor core/ periphery using a 2-tailed paired t-test (α = 0.05). Imaging was correlated with histopathology. RESULTS: Tumors were successfully grown in all rabbits, confirmed by necropsy. On DW-mRI, mean apparent diffusion coeffi cient (ADC) value was higher in necrotic tumor core (2.1 ± 0.3 mm2/s) than in viable tumor periphery (1.4 ± 0.5 mm2/s) (P mRI, mean perfusion values was higher in tumor periphery (110 ± 47 relative units) than in tumor core (66 ± 31 relative units) (P mRI can be used to differentiate necrotic from viable tumor cells in an animal pancreatic cancer model using ADC (DW-mRI) and perfusion (TRIP-mRI) values.

关键词： Animal model Functional magnetic resonance imaging Pancreatic cancer

Application of magnetic Survey in the Investigation of Iron Ore Deposits and Shear Zone Delineation: Case Study of mutomo-Ikutha Area, SE Kenya

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International Journal of Geosciences 2015年第7期6卷 729-740页

作者： aaron K. Waswa Christopher m. Nyamai Eliud mathu Daniel W. Ichang’i Department of Geology University of Nairobi Nairobi Kenya Department of Geological Sciences SE Kenya University Kitui Kenya

The main objective of this research was to use ground magnetic survey to delineate shear zone and iron ore deposit within the Neoproterozoic rocks of mutomo-Ikutha area of south eastern Kenya. Total field magnetic data was recorded by using high resolution proton precision geometric magnetometer which recorded total components of the ground magnetic anomaly data running through sixteen traverses. The field data was qualitatively and quantitatively interpreted and the results gave values for the total component measurements of ground magnetic anomaly that varied between a minimum negative peak value of about 250 nanoTesla and a maximum of about 1000 nanoTesla. 550 nanoTesla was considered to be threshold of the iron mineralization within the area. The results indicated that the western part of mutomo-Ikutha was sheared, faulted and contained iron ore mineralization trending in the north-south direction. Areas with high anomalous values were geochemically proven to contain magnetite.

关键词： Iron Ore magnetic Survey Neoproterozoic mutomo-Ikutha

Engineering microneedle Patches for Improved Penetration:Analysis,Skin models and Factors Affecting Needle Insertion

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Nano-micro Letters 2021年第6期13卷 190-230页

作者： Pooyan makvandi melissa Kirkby aaron RJHutton majid Shabani Cynthia K.Y.Yiu Zahra Baghbantaraghdari Rezvan Jamaledin marco Carlotti Barbara mazzolai Virgilio mattoli Ryan F.Donnelly Istituto Italiano Di Tecnologia Centre for Materials InterfaceViale Rinaldo Piaggio 3456025 PontederaPisaItaly School of Pharmacy Queen’s University Belfast97 Lisburn RoadBelfast BT97BLUK The BioRobotics Institute Scuola Superiore Sant’AnnaViale Rinaldo Piaggio 3456025 PontederaPisaItaly Paediatric Dentistry and Orthodontics Faculty of DentistryThe University of Hong KongPrince Philip Dental HospitalHong Kong SARChina Department of Chemical Materials and Industrial Production EngineeringUniversity of Naples FedericoⅡ80125 NaplesItaly Center for Advanced Biomaterials for Health Care(iit@CRIB) Italian Institute of Technology80125 NaplesItaly

Transdermal microneedle(mN)patches are a promising tool used to transport a wide variety of active compounds into the *** serve as a substitute for common hypodermic needles,mNs must pierce the human stratum corneum(~10 to 20μm),without rupturing or bending during *** ensures that the cargo is released at the predetermined place and ***,the ability of mN patches to sufficiently pierce the skin is a crucial *** the current review,the pain signal and its management during application of mNs and typical hypodermic needles are presented and *** is followed by a discussion on mechanical analysis and skin models used for insertion tests before application to clinical *** that affect insertion(e.g.,geometry,material composition and cross-linking of mNs),along with recent advancements in developed strategies(e.g.,insertion responsive patches and 3D printed biomimetic mNs using two-photon lithography)to improve the skin penetration are highlighted to provide a backdrop for future research.

关键词： Insertion responsive Implantable microneedles Skin indentation Transdermal microneedles Pain management

Bone mineral “Quality”: Differing Characteristics of Calcified microsphere Populations at the Osteoporotic and Osteoarthritic Femoral Articulation Front

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Journal of Biomedical Science and Engineering 2014年第9期7卷 739-755页

作者： Kathryn m. Linton Lesley D. Hordon Roger C. Shore Jean E. aaron Institute of membrane and Systems Biology Faculty of Biological Sciences University of Leeds Leeds UK Oral Biology Department Leeds Dental Institute University of Leeds Leeds UK

The mineral front consists of large populations of organically enshrouded calcified microspheres (filamentous clusters) about 1 micron in diameter and associated smaller numbers of variably dense nanospheres, 30 - 40 nm in diameter. The discrete objects persist and modulate in maturity, and may constitute a variable “qualitative” factor in the skeletal inorganic phase, exemplified by the biomechanically contrasting pathologies of osteoporosis (OP;fracture, low stress condition) and osteoarthritis (OA;non fracture, high stress condition). The aim was to compare the articulation front material for morphological and trace element diversity using fresh female femoral head discards (from Dewsbury District Hospital NHS mid-Yorkshire Trust). These were prepared for histology of the cartilage/bone interface region by immersion in hydrazine hydrate to expose the anorganic mineral topography for microscopy and FEGSEm microanalysis. 1) mineral microsphere morphology (compared to animals as arbitrary controls) suggested that calcified microspheres from OP (n = 19) tended to be small (0.5 - 0.7 microns), smooth and compacted;those from OA (n = 19) were large (0.5 - 4.0 microns), uneven and irregularly dispersed. Respective calcified nanospheres from OP were similarly smaller (30 - 50 nm) than those from OA (>100 nm). In subchondral bone a proportion of the filamentous microspheres had fused into a fine-textured phase in OP and a coarse-textured phase in OA. 2) Trace element analysis (compared to positive porcine Si and mg and other peaks) suggested a diminution with mineral maturity, and also with age effecting OP and OA similarly, with minor differences detected between them. It was concluded that calcified objects constituting the inorganic phase vary regionally with age and in fracture and nonfracture, being diminished in size (not number) in weak OP and enlarged (compared to porcine control) in stronger OA, with Si or mg “doping” diminishing with time, perhaps influencing th

关键词： Bone mineral Quality Calcified microspheres Si mg Trace Elements Osteoporosis Osteoarthritis

Suspension electrospinning of decellularized extracellular matrix: A new method to preserve bioactivity

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Bioactive materials 2024年第11期41卷 640-656页

作者： Sarah Jones Sabrina VandenHeuvel Andres Luengo martinez Ruchi Birur Eric Burgeson Isabelle Gilbert aaron Baker matthew Wolf Shreya A.Raghavan Simon Rogers Elizabeth Cosgriff-Hernandez Department of Biomedical Engineering The University of Texas at AustinAustinTX78712USA Department of Biomedical Engineering Texas A&M UniversityCollege StationTX77843USA Department of Chemical and Biomolecular Engineering University of Illinois Urbana-ChampaignChampaignIL61820USA Cancer Biomaterials Engineering Section Cancer Innovation LaboratoryCenter for Cancer ResearchNational Cancer InstituteFrederickMD21702USA

Decellularized extracellular matrices (dECm) have strong regenerative potential as tissue engineering scaffolds;however, current clinical options for dECm scaffolds are limited to freeze-drying its native form into sheets. Electrospinning is a versatile scaffold fabrication technique that allows control of macro- and microarchitecture. It remains challenging to electrospin dECm, which has led researchers to either blend it with synthetic materials or use enzymatic digestion to fully solubilize the dECm. Both strategies reduce the innate bioactivity of dECm and limit its regenerative potential. Herein, we developed a new suspension electrospinning method to fabricate a pure dECm fibrous mesh that retains its innate bioactivity. Systematic investigation of suspension parameters was used to identify critical rheological properties required to instill “spinnability,” including homogenization, concentration, and particle size. Homogenization enhanced particle interaction to impart the requisite elastic behavior to withstand electrostatic drawing without breaking. A direct correlation between concentration and viscosity was observed that altered fiber morphology;whereas, particle size had minimal impact on suspension properties and fiber morphology. The versatility of this new method was demonstrated by electrospinning dECm with three common decellularization techniques (Abraham, Badylak, Luo) and tissue sources (intestinal submucosa, heart, skin). Bioactivity retention after electrospinning was confirmed using cell proliferation, angiogenesis, and macrophage polarization assays. Collectively, these findings provide a framework for researchers to electrospin dECm for diverse tissue engineering applications.

关键词： Electrospinning Extracellular matrix Biological scaffolds

Artificial intelligence for pancreatic cancer detection: Recent development and future direction

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Artificial Intelligence in Gastroenterology 2021年第2期2卷 56-68页

作者： Passisd Laoveeravat Priya R Abhyankar aaron R Brenner moamen m Gabr Fadlallah G Habr Amporn Atsawarungruangkit Division of Digestive Diseases and Nutrition University of Kentucky College of MedicineLexingtonKY 40536United States Department of Internal medicine University of Kentucky College of MedicineLexingtonKY 40536United States Division of Gastroenterology Warren Alpert Medical School of Brown UniversityProvidenceRI 02903United States

Artificial intelligence(AI)has been increasingly utilized in medical applications,especially in the field of *** can assist gastroenterologists in imaging-based testing and prediction of clinical diagnosis,for examples,detecting polyps during colonoscopy,identifying small bowel lesions using capsule endoscopy images,and predicting liver diseases based on clinical *** its high mortality rate,pancreatic cancer can highly benefit from AI since the early detection of small lesion is difficult with conventional imaging techniques and current *** ultrasound(EUS)is a main diagnostic tool with high sensitivity for pancreatic adenocarcinoma and pancreatic cystic *** standard tumor markers have not been effective for *** have been recent research studies in AI application in EUS and novel biomarkers to early detect and differentiate malignant pancreatic *** findings are impressive compared to the available traditional ***,we aim to explore the utility of AI in EUS and novel serum and cyst fluid biomarkers for pancreatic cancer detection.

关键词： Artificial intelligence machine learning Deep learning Endoscopic ultrasound microRNA Pancreatic cancer Pancreatic cyst

The Biodegradation of Dispersed Oil Does Not Induce Toxicity at Environmentally-Relevant Concentrations

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Open Journal of marine Science 2019年第3期9卷 113-120页

作者： Roger C. Prince Bryan m. Hedgpeth aaron D. Redman Josh D. Butler Exxonmobil Biomedical Sciences Inc. Annandale NJ USA

Applying dispersants to spilled crude oil results in an oil in water dispersion of microscopic oil droplets that soon dilutes to levels below 1 ppm oil. These levels are substantially below those known to induce acute toxicity in 96-hour tests. We show here that oil hydrocarbons are biodegraded very rapidly in such situations (50% loss in 4 days in this experiment), and that no increase in acute toxicity to mysids (Americamysis bahia) is seen during this biodegradation, or over the following 20 days as the oil is further degraded (78% loss of detectable hydrocarbons in this experiment).

关键词： Oil Spills Dispersants Biodegradation Acute Toxicity Hopane Americamysis bahia

共价有机骨架纳滤膜的制备和有机污染物去除研究

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共价有机骨架纳滤膜的制备和有机污染物去除研究

作者： aaron S Pittman 天津大学

学位级别：硕士

膜分离技术因其设备投资小、低能源消耗和稳定性能在水处理中发挥着重要作用。然而,分离膜固有的渗透性-选择性的权衡效应仍然是制约膜分离技术广泛应用的重大障碍。共价有机框架材料(COF)是一种高度稳定且完全由有机分子组成的结晶框... 详细信息

膜分离技术因其设备投资小、低能源消耗和稳定性能在水处理中发挥着重要作用。然而,分离膜固有的渗透性-选择性的权衡效应仍然是制约膜分离技术广泛应用的重大障碍。共价有机框架材料(COF)是一种高度稳定且完全由有机分子组成的结晶框架材料,其多样化结构特性引起科学家们的关注。目前,基于COFs纳滤膜的制备研究仍然缺乏简便而温和的方法。界面聚合(IP)过程是一种成熟的纳滤膜制备方法。因此,本研究尝试通过界面聚合过程制备高性能COFs纳滤膜,并研究其有机污染物的脱除过程。本研究采用界面聚合技术制备了一种具有高渗透通量和截留率的COFs纳滤膜。首先,实验采用1,2,3-三氨基胍盐酸盐(TAGH)为水相单体,2,5-二羟基对苯二甲醛(Dha)为有机相单体,通过界面聚合反应在聚砜(PSf)基膜表面成功制备出连续无缺陷的共价有机框架纳滤膜。实验采用傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEm)、X射线衍射仪(XRD)对COFs纳滤膜进行结构表征,分析COFs纳滤膜的化学组成、表面形貌和晶态结构,从而验证COFs选择层的成功制备。实验系统评价了COFs纳滤膜的渗透选择性能。采用制备的TAGH-Dha/PSf纳滤膜在25°C和3 bar的操作压力下对染料分子的水溶液进行分离,其渗透通量约为40.2L·m·h·bar,对CB-T和CR染料分子的截留率高于98%,AF的截留率为95.3%,mB的截留率为95%,AO7的截留率为89%。进而,采用制备的TAGH-Dha/PSf纳滤膜在25°C和3 bar的操作压力下对1000 ppm NaSO溶液进行分离,其渗透通量为19.9 Lmh,NaSO截留率为12.8%。与文献报道的COFs纳滤膜相比,制备的TAGH-Dha/PSf膜表现出较高的渗透通量和染料脱除性能。因此,本工作成功在多孔基底上制备具有良好渗透选择性能和稳定性能的COFs纳滤膜,在有机污染物去除方面具有一定的应用潜力。

关键词：共价有机骨架纳滤膜界面聚合染料去除

Cisplatin-Induced Posterior Reversible Encephalopathy Syndrome—Brief Report and Review of the Literature

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Journal of Behavioral and Brain Science 2012年第1期2卷 97-101页

作者： Limor Amit Irit Ben-Aharon Thomas Tichler Edna Inbar aaron Sulkes Salomon m. Stemmer Department of Radiology Rabin medical Center Beilinson Campus Petah-Tiqva Israel Institute of Oncology Davidoff Center Rabin Medical Center Beilinson Campus Petah-Tiqva Israel The Sackler Faculty of medicine Tel Aviv University Tel Aviv Israel

Cisplatin is one of the most broadly used chemotherapeutic agents. Several central nervous system toxicities have been attributed to this agent, among which is a rare clinicoradiological condition referred to as posterior reversible leukoen-cephalopathy syndrome (PRES) or reversible posterior leukoencephalopathy syndrome (RPLS). PRES is characterized by subacute onset of headache, visual disturbances, confusion, seizures and rarely, coma. This usually reversible syn-drome was associated in the past mainly with hypertension. Several reports have associated the syndrome with several immunosuppressive and chemotherapeutic agents suggesting a disruption of the blood brain barrier due to direct damage to the endothelium and vasogenic edema. This syndrome is readily diagnosed with Computed Tomography (CT) or magnetic resonance imaging (mRI) studies and quick withdrawal of the causative agent in conjunction with supportive care including rapid hypertension control and reduction of elevated intracranial pressure when needed, usually reverse the neurological symptoms with minimal or even no sequela within several days. In this brief report and review of the literature we describe two cases of PRES in two female patients that occurred a few days after receiving Cisplatin-based chemotherapy. We discuss the clinical presentation, diagnosis and treatment of this syndrome by reviewing the literature. The escalating number of clinical reports of PRES merit further studies of the mechanism of toxicity, appropriate treatment and awareness of physicians to this life threatening

关键词： PRES RPLS Encephalopathy Cisplatin Hypertension