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Enamel biomimetics—fiction or future of dentistry?

International Journal of Oral Science 2019年第1期11卷 1-9页

作者： Mirali Pandya thomas g.h.diekwisch Center for Craniofacial Research and Diagnosis Texas A&M College of Dentistry

Tooth enamel is a complex mineralized tissue consisting of long and parallel apatite crystals configured into decussating enamel rods. In recent years, multiple approaches have been introduced to generate or regenerate this highly attractive biomaterial characterized by great mechanical strength paired with relative resilience and tissue compatibility. In the present review, we discuss five pathways toward enamel tissue engineering,(i) enamel synthesis using physico-chemical means,(ii) protein matrix-guided enamel crystal growth,(iii) enamel surface remineralization,(iv) cell-based enamel engineering, and(v) biological enamel regeneration based on de novo induction of tooth morphogenesis. So far, physical synthesis approaches using extreme environmental conditions such as ph, heat and pressure have resulted in the formation of enamel-like crystal *** methods relying on enamel proteins as templating matrices have aided the growth of elongated calcium phosphate crystals. To illustrate the validity of this biochemical approach we have successfully grown enamel-like apatite crystals organized into decussating enamel rods using an organic enamel protein matrix. Other studies reviewed here have employed amelogeninderived peptides or self-assembling dendrimers to re-mineralize mineral-depleted white lesions on tooth surfaces. So far, cell-based enamel tissue engineering has been hampered by the limitations of presently existing ameloblast cell lines. going forward, these limitations may be overcome by new cell culture technologies. Finally, whole-tooth regeneration through reactivation of the signaling pathways triggered during natural enamel development represents a biological avenue toward faithful enamel regeneration. In the present review we have summarized the state of the art in enamel tissue engineering and provided novel insights into future opportunities to regenerate this arguably most fascinating of all dental tissues.

关键词： complex mineralized Biochemical methods

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MicroRNAs and immunity in periodontal health and disease

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International Journal of Oral Science 2018年第3期10卷 133-146页

作者： Xianghong Luan Xiaofeng Zhou Afsar Naqvi Marybeth Francis Deborah Foyle Salvador Nares thomas g.h.diekwisch Department of Oral Biology UIC College of DentistryChicagoILUSA Department of Periodontics UIC College of DentistryChicagoILUSA Department of Periodontics Texas A&M College of DentistryChicagoILUSA

MicroRNAs(miRNAs) are critical regulators of the host immune and inflammatory response against bacterial pathogens. In the present review, we discuss target genes, target gene functions, the potential regulatory role of miRNAs in periodontal tissues, and the potential role of miRNAs as biomarkers and therapeutics. In periodontal disease, miRNAs exert control over all aspects of innate and adaptive immunity, including the functions of neutrophils, macrophages, dendritic cells and T and B cells. Previous human studies have highlighted some key miRNAs that are dysregulated in periodontitis patients. In the present study, we mapped the major miRNAs that were altered in our reproducible periodontitis mouse model relative to control animals. The miRNAs that were upregulated as a result of periodontal disease in both human and mouse studies included miR-15 a, miR-29 b, miR-125 a, miR-146 a,miR-148/148 a and miR-223, whereas miR-92 was downregulated. The association of individual miRNAs with unique aspects of periodontal disease and their stability in gingival crevicular fluid underscores their potential as markers for periodontal disease progression or healthy restitution. Moreover, miRNA therapeutics hold great promise for the future of periodontal therapy because of their ability to modulate the immune response to infection when applied in conjunction with synthetic antagomirs and/or relatively straightforward delivery strategies.

关键词： RNA In MicroRNAs and immunity in periodontal health and disease

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Silk-based nerve guidance conduits with macroscopic holes modulate the vascularization of regenerating rat sciatic nerve

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Neural Regeneration Research 2025年第6期20卷 1789-1800页

作者： Carina hromada Patrick heimel Markus Kerbl Lászlógál Sylvia Nürnberger Barbara Schaedl James Ferguson Nicole Swiadek Xavier Monforte Johannes C.heinzel Antal Nógrádi Andreas h.Teuschl-Woller David hercher Department Life Science Engineering University of Applied Sciences Technikum WienViennaAustria Austrian Cluster for Tissue Regeneration ViennaAustria Ludwig Boltzmann Institute for Traumatology The Research Center in Cooperation with AUVAViennaAustria University Clinic of Dentistry Medical University of ViennaViennaAustria Department of Plastic Reconstructive and Aesthetic SurgeryLandesklinikum Wiener Neustadt2700 Wiener NeustadtAustria Department of Anatomy Histology and EmbryologyAlbert Szent-Györgyi Medical SchoolUniversity of SzegedSzegedHungary Medical University of Vienna Department of Orthopedics and Trauma SurgeryDevision of Trauma SurgeryViennaAustria Department of hand- PlasticReconstructive and Burn SurgeryBG Unfallklinik TuebingenUniversity of TuebingenTuebingenGermany

Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tNgCs). however, the use of tNgCs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tNgC would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tNgCs and compared the various features of these improved silk^(+) tNgCs with the tubes without holes(silk^(–) tNgCs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tNgCs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tNgCs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tNgCs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tNgCs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimizatio

关键词： axon regeneration blood vessel functional recovery macroporous nerve lesion peripheral nerve repair sciatic nerve silk-based nerve guidance conduit vascularization

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Numerical simulation on inclusion transport in continuous casting mold

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Journal of University of Science and Technology Beijing 2006年第4期13卷 293-300页

作者： Lifeng Zhang Brian g thomas Department of Materials Science ＆ Engineering Norwegian University of Science ＆ Technology （NTNU） Alfred Getz vei 2 N-7491 Trondheim Norway University of Illinois at Urbana-Champaign 1206 W. Green St. Urbana IL 61801 USA

Turbulent flow, the transpor＇t of inclusions and bubbles, and inclusion removal by fluid flow, transport and by bubble flotation in the strand of the continuous slab caster are investigated using computational models, and validated through comparison with plant measurements of inclusions. Steady 3-D flow of steel in the liquid pool in the mold and upper strand is simulated with a finitedifference computational model using the standard k-εturbulence rondel. Trajectories of inclusions and bubhles tire calculated by integrating each local velocity, considering its drag and buoyancy forces, A ＂random walk＂ model is used to incorporate the effect of turbulent fluctuations on the particle motion. The attachment probability of inclusions on a bubble surface is investigated based on fundamental fluid flow simulations, incorporating the turbulent inclusion trajectory and sliding time of each individual inclusion along the bubble surface as a function of particle and bubble size. The chunge in inclusion distribution due to removal by bubble transport in the mold is calculated based on the computed attachment probability of inclusions on each bubble and the computed path length of the bubbles. The results indicate that 6%-10% inclusions are removed by fluid flow transport. 10% by bubble flotation, and 4% by entrapment to the submerged entry nozzle （SEN） walls. Smaller bubbles and larger inclusions have larger attachment probabilities. Smaller bubbles are more efficient for inclusion removal by bubble flotation, so Inng as they are not entrapped in the solidifying shell A larger gas flow rate favors inclusion removal by bubble flotation. The optimum bubble size should be 2-4mm.

关键词： inclusion removal fluid flow transport bubble flotation continuous casting mold attachment probability

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Identification and Characterization of Reduced Epicuticular Wax Mutants in Rice

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Rice science 2015年第4期22卷 171-179页

作者： thomas h.TAI United States Department of Agriculture-Agricultural Research Service Crops Pathology and Genetics Research UnitDepartment of Plant SciencesMail Stop 1University of California

Epicuticular wax forms the outermost protective barrier of the aerial surfaces of land plants, working in concert with other components of the plant cuticle to prevent uncontrolled loss of water and to provide protection against an array of external environmental stress. In this study, chemically- mutagenized populations of rice （Oryza sativa L.） derived from approximately 4 750 M2 families were screened for adhesion of water droplets resulting in a wet leaf/glossy （wig） phenotype. Mutants were identified in 11 independently-derived M2 families. Scanning electron microscopy analysis confirmed the association of the wig phenotype with changes in the epicuticular wax crystals of these plants. The phenotypes of five mutants （7-17A, 26.1, 524.2, 680.2, and 843.1） were confirmed to be the result of single recessive gene mutation. Evaluation of mutants from 3 （6-1A, 7-17A, and 11-39A） of 11 M2 families revealed significant reductions （〉 50%） in surface wax content and increases in cuticle membrane permeability.

关键词： chemical mutagenesis cuticle wax forward genetics membrane permeability rice scanning electron microscopy

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Robust artificial intelligence and robust human organizations

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Frontiers of Computer Science 2019年第1期13卷 1-3页

作者： thomas g.DIETTERICh Kelley Engineering Center Oregon State UniversityCorvallis OR 97331USA

The more powerful technology becomes,the more it magni- fies design errors and human *** angry man who has only his fists,cannot hurt very many *** the same man with a machine gun can kill hundreds in just a few *** technologies under the name of "artificial intelligence"(AI)are likely to provide many new opportunities to observe this "fault magnification"*** society contemplates deploying AI in self-driving cars,in surgical robots,in police activities,in managing critical infrastructure,and in weapon systems,it is creating situations in which errors committed by human users or errors in the software could have catastrophic consequences. Are these consequences inevitable?In the wake of the Three Mile Island nuclear power plant failure,Perrow [1] published his book "Normal Accidents"in which he argued that in any sufficiently complex system,with sufficiently many feedback loops,catastrophic accidents are "normal"-- that is,they can not be avoided.

关键词： Robust artificial organizations

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Muscle function, physical performance and body composition changes in men with prostate cancer undergoing androgen deprivation therapy

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Asian Journal of Andrology 2012年第2期14卷 204-221页

作者： thomas W Storet Renee Miciek thomas g Travison Section of Endocrinology Diabetes and Nutrition Boston University School of Medicine Boston MA 02118 USA

Prostate cancer （PCa） is the most common visceral malignancy in men with androgen deprivation therapy （ADT） the preferred therapy to suppress testosterone production and hence tumor growth. Despite its effectiveness in lowering testosterone, ADT is associated with side effects including loss of muscle mass, diminished muscle strength, decrements in physical performance, earlier fatigue and declining quality of life. This review reports a survey of the literature with a focus on changes in muscle strength, physical function and body composition, due to short-term and long-term ADT. Studies in these areas are sparse, especially well-controlled, prospective randomized trials. Cross-sectional and longitudinal data （up to 2 years） for men with PCa treated with ADT as well as patients with PCa not receiving ADT and age-matched healthy men are presented when available. Based on limited longitudinal data, the adverse effects of ADT on muscle function, physical performance and body composition occur shortly after the onset of ADT and tend to persist and worsen over time. Exercise training is a safe and effective intervention for mitigating these changes and initial guidelines for exercise program design for men with PCa have been published by the American College of Sports Medicine. Disparities in study duration, types of studies and other patient-specific variables such as time since diagnosis, cancer stage and comorbidities may all affect an understanding of the influence of ADT on health, physical performance and mortality.

关键词： androgen deprivation therapy androgen suppression exercise prescription exercise training functional assessment lean body mass older men prostate cancer

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New multi protein patterns differentiate liver fibrosis stages and hepatocellular carcinoma in chronic hepatitis C serum samples

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World Journal of gastroenterology 2006年第47期12卷 7604-7612页

作者： thomas gbel Sonja Vorderwülbecke Katarzyna hauck holger Fey Dieter hussinger Andreas Erhardt Klinik für gastroenterologie Hepatologie und InfektiologieHeinrich-Heine-UniversitatDusseldorfMoorenstr.eD-40225 DusseldorfGermany Ciphergen Biosystems Neuendorfstr.24aD-16761 Hennigsdorf bei berlinGermany

AIM： To identify a multi serum protein pattern as well as single protein markers using surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry （SELDI-TOF-MS） for detection and differentiation of liver fibrosis （F1-F2）, liver cirrhosis （F4） and hepatocellular carcinoma （hCC） in patients with chronic hepatitis C virus （hCV）. METhODS： Serum samples of 39 patients with F1/F2 fibrosis, 44 patients with F4 fibrosis, 34 patients with hCC were applied to CM10 arrays and analyzed using the SELDI-TOF ProteinChip System （PBS-Ⅱc; Ciphergen Biosystems） after anion-exchange fractionation. All patients had chronic hepatitis C and histologically confirmed fibrosis stage/hCC. Data were analyzed for protein patterns by multivariate statistical techniques and artificial neural networks. RESULTS： A 4 peptide/protein multimarker panel （7486, 12843, 44293 and 53598 Da） correctly identified hCCs with a sensitivity of 100% and specificity of 85% in a two way-comparison of hCV-cirrhosis versus hCV-hCC training samples （AUROC 0.943）. Sensitivity and specificity for identification of hCC were 68% and 80% for random test samples. Cirrhotic patients could be discriminated against patients with F1 or F2 fibrosis using a 5 peptide/protein multimarker pattern （2873, 6646, 7775, 10525 and 67867 Da） with a specificity of 100% and a sensitivity of 85% in training samples （AUROC 0.976） and a sensitivity and specificity of 80% and 67% for random test samples. Combination of the biomarker classifiers with APR/score and alfa-fetopotein （AFP） improved the diagnostic performance. The 6646 Da marker protein for liver fibrosis was identified as apolipoprotein C-I. CONCLUSION： SELDI-TOF-MS technology combined with protein pattern analysis seems a valuable approach for the identification of liver cirrhosis and hepatocellular carcinoma in patients with chronic hepatitis C. host probably a combination of different serum markers will help to identify liver cirrhosis and early-stage hep

关键词： hepatocellular carcinoma hepatitis C virus Apolipoprotein C- I Proteomics Surface-enhanced laser desorption/ionisation

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An approximate point-based alternative for the estimation of variance under big BAF sampling

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Forest Ecosystems 2021年第3期8卷 439-457页

作者： thomas B.Lynch Jeffrey h.gove Timothy g.gregoire Mark J.Ducey Professor Emeritus Department of Natural Resource Ecology and ManagementOklahoma State UniversityAg Hall Room 008CStillwater 74078OKUSA USDA Forest Service Northern Research Station271 Mast RoadDurham 03824NHUSA Yale School of Environment Yale University360 Prospect StNew Haven 06511CTUSA Department of Natural Resources and the Environment University of New Hampshire114 James HallDurham 03824NHUSA

Background:A new variance estimator is derived and tested for big BAF(Basal Area Factor)sampling which is a forest inventory system that utilizes Bitterlich sampling(point sampling)with two BAF sizes,a small BAF for tree counts and a larger BAF on which tree measurements are made usually including DBhs and heights needed for volume ***:The new estimator is derived using the Delta method from an existing formulation of the big BAF estimator as consisting of three sample *** new formula is compared to existing big BAF estimators including a popular estimator based on Bruce’s ***:Several computer simulation studies were conducted comparing the new variance estimator to all known variance estimators for big BAF currently in the forest inventory *** simulations the new estimator performed well and comparably to existing variance ***:A possible advantage of the new estimator is that it does not require the assumption of negligible correlation between basal area counts on the small BAF factor and volume-basal area ratios based on the large BAF factor selection trees,an assumption required by all previous big BAF variance estimation *** this correlation was negligible on the simulation stands used in this study,it is conceivable that the correlation could be significant in some forest types,such as those in which the DBh-height relationship can be affected substantially by density perhaps through *** derived a formula that can be used to estimate the covariance between estimates of mean basal area and the ratio of estimates of mean volume and mean basal *** also mathematically derived expressions for bias in the big BAF estimator that can be used to show the bias approaches zero in large samples on the order of 1n where n is the number of sample points.

关键词： Bitterlich sampling Delta method Double sampling Estimator bias Forest inventory horizontal point sampling Variance of a product Volume basal area ratio Covariance estimation

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A note on the estimation of variance for big BAF sampling

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Forest Ecosystems 2020年第4期7卷 819-832页

作者： Jeffrey h.gove Timothy g.gregoire Mark J.Ducey thomas B.Lynch USDA Forest Service Northern Research Station271 Mast RoadDurham NH03824USA. School of Forestry&Environmental Studies Yale University360 Prospect StNew Haven CT06511USA. Department of Natural Resources and the Environment University of New Hampshire114 James HallDurham NH03824USA. Professor Emeritus Department of Natural Resource Ecology and ManagementOklahoma State UniversityAg Hall Room 008CStillwater OK74078USA.

Background:The double sampling method known as“big BAF sampling”has been advocated as a way to reduce sampling effort while still maintaining a reasonably precise estimate of volume.A well-known method for variance determination,Bruce’s method,is customarily used because the volume estimator takes the form of a product of random ***,the genesis of Bruce’s method is not known to most foresters who use the method in ***:We establish that the Taylor series approximation known as the Delta method provides a plausible explanation for the origins of Bruce’s *** were conducted on two different tree populations to ascertain the similarities of the Delta method to the exact variance of a ***,two alternative estimators for the variance of individual tree volume-basal area ratios,which are part of the estimation process,were compared within the overall variance estimation ***:The simulation results demonstrate that Bruce’s method provides a robust method for estimating the variance of inventories conducted with the big BAF *** simulations also demonstrate that the variance of the mean volume-basal area ratios can be computed using either the usual sample variance of the mean or the ratio variance estimators with equal accuracy,which had not been shown previously for Big BAF ***:A plausible explanation for the origins of Bruce’s method has been set forth both historically and mathematically in the Delta *** most settings,there is evidently no practical difference between applying the exact variance of a product or the Delta method—either can be used.A caution is articulated concerning the aggregation of tree-wise attributes into point-wise summaries in order to test the correlation between the two as a possible indicator of the need for further covariance augmentation.

关键词： Bitterlich sampling Delta method Double sampling Forest inventory horizontal point sampling Variance of a product

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