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1.
J World Fed Orthod ; 11(2): 80-94, 2022 04.
Article in English | MEDLINE | ID: mdl-35120859

ABSTRACT

This case report describes the successful orthodontic treatment of a 22-year-old female patient affected by Class II malocclusion, maxillary skeletal transverse deficiency, ectopic maxillary left lateral incisor, and mild mandibular crowding. Due to her adult skeletal age, a bone-borne appliance was applied in order to obtain both purely skeletal rapid maxillary expansion and bilateral molar distalization. After accurate matching between the pretreatment cone-beam computed tomography scan and digital models, 4 self-drilling miniscrews were inserted palatally using a computer-aided design and computer-aided manufacturing (CAD/CAM) surgical template to guide their correct and safe placement, and a bone-borne appliance was fitted. After this first phase, the hybrid clear aligner approach was used to obtain alignment, levelling, and arch coordination, with the use of a partial lingual fixed appliance on the maxillary incisors.


Subject(s)
Orthodontic Anchorage Procedures , Orthodontic Appliances, Removable , Adult , Cephalometry/methods , Female , Humans , Orthodontic Appliance Design , Tooth Movement Techniques , Young Adult
2.
Clin Oral Investig ; 26(4): 3523-3532, 2022 Apr.
Article in English | MEDLINE | ID: mdl-34837567

ABSTRACT

OBJECTIVE: This study aims to evaluate success factors implicated in clinical orthodontic miniscrew stability after their interradicular placement in maxilla. MATERIALS AND METHODS: Six hundred seventy-six miniscrews were inserted in maxillary interradicular sites in a sample of 276 patients (109 males and 167 females; mean age 19 ± 1.7 years) and immediately loaded. Percentage failure rate was recorded, and the influence of the following factors was investigated: structural (miniscrew length, diameter and body shape), operative (side of insertion site, pilot hole drilling or not) and biological (maximal insertion torque [MIT] and type of gingiva). A chi-square test with Monte Carlo correction was performed to detect the influence of these variables on the failure rate of orthodontic miniscrews. Then both multivariate logistic regression and post hoc analysis were performed, followed by classification and regression tree (CART) analysis. RESULTS: The average success rate was 88%. The principal factors implicated in the failure rate were miniscrew length, MIT values and type of gingiva. Specifically, 8 mm miniscrew length, alveolar mucosa and 5-10 Ncm MIT values were linked to higher failure rates. According to CART, the main variable influencing failure is miniscrew length (≤ 8 mm for higher failure rates). For others, MIT values of 5-10 Ncm are linked to higher failure rates (p < 0.05). CONCLUSION: Orthodontic miniscrews inserted in the maxilla display good success rates. However, clinicians should be discouraged from using miniscrews of length ≤ 8 mm and MIT values < 10 Ncm, even with longer miniscrews. CLINICAL RELEVANCE: Information about factors related to failure rate of miniscrews placed at posterior maxillary interradicular sites is given.


Subject(s)
Maxilla , Orthodontic Anchorage Procedures , Adolescent , Adult , Bone Screws , Female , Gingiva , Humans , Male , Maxilla/surgery , Torque , Young Adult
3.
Dalton Trans ; 46(43): 14934-14946, 2017 Nov 07.
Article in English | MEDLINE | ID: mdl-29043335

ABSTRACT

LiMn2O4 (LMO) is interesting from the viewpoint of its energy storage applications as it is a cathode in lithium ion batteries (LIB), which contains no rare, toxic or expansive elements, while it provides a high theoretical capacity (148 mA h g-1) at a reasonable voltage (4 V region) and a higher thermal stability compared to cobalt based cathodes and has a good rechargeability and cycling stability due to its spinel structure. Low temperature synthesis routes for cathode materials are currently gaining attention, in order to decrease the ecological footprint of the final LIB. Here, the crystallization temperature of LMO by a citrate based solution-gel synthesis was significantly lowered, to as low as 250 °C by the addition of ethanol to the precursor. The role of ethanol in this synthesis process was explored. It was found to lead to a considerable increase in the oxidation rate of the redox couple Mn2+/Mn3+, a lowering of the precursor decomposition temperature by 200 °C, besides a drastic decrease in the crystallization temperature (reaching 250 °C). Moreover, the main cause was identified to be an esterification reaction of ethanol with the carboxylic acid in the precursor complexes, taking place before the oxide formation. The insights obtained strengthen the knowledge regarding citrato-Mn2+/Mn3+ complexes present in aqueous solution-gel synthesis routes and are relevant for the preparation of various manganese containing oxides. Moreover, the precursor developed opens up a new possibility for the low temperature synthesis of LMO powders and thin films for application in LIB. In the case of thin film batteries, the low temperature processing provides compatibility with other materials in the thin film battery stack, avoiding undesired oxidations or interfacial reactions.

4.
Appl Radiat Isot ; 53(4-5): 571-9, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11003493

ABSTRACT

A multivariate approach based on Principal Component Analysis (PCA) was used to analyze the energy distribution of n Monte Carlo simulated Compton scattered photon spectra describing the electron density of large layers. Three to five layers with different density distribution were used to test the algorithm; each layer was obtained by collecting 25 Compton spectra coming from sensitive volumes (SVs) where the complementary conditions of high and low density were realized (respectively full and void SV). The density variation inside a single layer is described by a two principal components (PCs) linear model that depicts the electron density of each SV: the layer density distribution appears to be correctly described even in the presence of very low signal-to-noise Compton spectra. Density profiles for layers at different depths were comparatively analyzed in order to show that, at least within one mean-free-path distance, it is possible to describe the layer density distribution by the PCA without any correction for the beam attenuation.

5.
Am J Pathol ; 145(1): 211-9, 1994 Jul.
Article in English | MEDLINE | ID: mdl-8030750

ABSTRACT

Endothelial cells (EC) cultured on polymerized silicone deform the underlying substrate, producing microscopically visible wrinkles. This has been interpreted as cellular contraction, and we have previously concluded that EC normally maintain an active contractile tone. Since in ischemic tissues capillaries become "paralyzed" and lose their tone, we decided to examine the effects of glucose and/or oxygen deprivation on EC contractility. Contracting cultures with wrinkled silicone substrates were exposed to complete anoxia with or without exogenous glucose and followed by time-lapse photography. Under either glucose-or oxygen-free conditions, contraction was maintained for up to 4 days. If, however, both oxygen and glucose were removed, cellular contraction was reversed. After a period of 2 to 4 hours substrate wrinkles gradually disappeared, until by 3 to 7 hours, few to no wrinkles remained. Furthermore, within 10 minutes of restoration to normal oxygen (but not glucose) levels, substrate wrinkling reappeared. F-actin microfilament patterns and cell number per unit area were also altered by glucose and oxygen deprivation. Similar results were obtained using large or small vessel EC. We conclude that in the absence of glucose and oxygen EC lose their contractile tone, and that tone can be re-established upon re-exposure to oxygen. These findings should have implications for the pathogenesis of capillary paralysis in ischemia.


Subject(s)
Cell Hypoxia/physiology , Endothelium, Vascular/physiopathology , Glucose/deficiency , Ischemia/physiopathology , Muscle Contraction/physiology , Muscle Relaxation/physiology , Muscle, Smooth, Vascular/physiopathology , Animals , Cell Count , Cells, Cultured , Endothelium, Vascular/ultrastructure , Microfilament Proteins/ultrastructure , Models, Biological , Rats , Time Factors
7.
Phys Rev C Nucl Phys ; 46(5): 1725-1734, 1992 Nov.
Article in English | MEDLINE | ID: mdl-9968293
8.
Phys Rev C Nucl Phys ; 44(4): 1508-1514, 1991 Oct.
Article in English | MEDLINE | ID: mdl-9967555
9.
10.
Eur Heart J ; 12(6): 712-9, 1991 Jun.
Article in English | MEDLINE | ID: mdl-1713557

ABSTRACT

Pentisomide, a new class I anti-arrhythmic drug, was compared to placebo in 50 hospitalized patients with frequent (greater than 30 h-1) and stable ventricular premature beats (VPB) (variation less than 50% between two preliminary and one placebo 24-h Holter recordings). All patients underwent a single-dose acute oral testing followed by a short-term testing with 300 mg t.i.d. for 4 days and then by a 4-day placebo period. For the studied population, a 56.4% reduction of simple VPB and a 98.8% decrease of couplets and runs were the minimum required to define the drug efficacy and to exclude spontaneous variability, using the linear regression analysis. Pentisomide was found effective in 27 (54%) of the 50 patients after the acute test and in 23 (46%) after the short-term test. The drug induced a mild increase of PR and QRS intervals, while QTc, heart rate, blood pressure and ejection fraction showed no significant variations. Subjective tolerability was excellent.


Subject(s)
Anti-Arrhythmia Agents , Cardiac Complexes, Premature/drug therapy , Electrocardiography, Ambulatory/drug effects , Propylamines/therapeutic use , Pyridines , Adult , Aged , Aged, 80 and over , Dose-Response Relationship, Drug , Drug Administration Schedule , Female , Heart Conduction System/drug effects , Heart Ventricles/drug effects , Hemodynamics/drug effects , Humans , Male , Middle Aged
15.
17.
Phys Rev C Nucl Phys ; 35(4): 1598-1599, 1987 Apr.
Article in English | MEDLINE | ID: mdl-9953944
18.
Phys Rev C Nucl Phys ; 34(4): 1223-1228, 1986 Oct.
Article in English | MEDLINE | ID: mdl-9953575
19.
Phys Rev C Nucl Phys ; 33(3): 1089-1092, 1986 Mar.
Article in English | MEDLINE | ID: mdl-9953245
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