The development of low temperature curing adhesives

An approach for the development of a practical low temperature (293 K-311 K/68 F-100 F) curing adhesive system based on a family of amide/ester resins was studied and demonstrated. The work was conducted on resin optimization and adhesive compounding studies. An improved preparative method was demonstrated which involved the reaction of an amine-alcohol precursor, in a DMF solution with acid chloride. Experimental studies indicated that an adhesive formulation containing aluminum powder provided the best performance when used in conjunction with a commercial primer

Effects of Implant Thread Geometry on Percentage of Osseointegration and Resistance to Reverse Torque in the Tibia of Rabbits

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141256/1/jper1233.pd

Schneiderian membrane perforation via transcrestal sinus floor elevation: A randomized ex vivo study with endoscopic validation

ObjectiveTo endoscopically determine the incidence of Schneiderian membrane perforation during transcrestal maxillary sinus floor elevation (SFE), in relation to the bone preparation technique, amount of bone graft, membrane elevation height and different surgical steps.Materials and methodsSeven cadaver heads corresponding to 12 maxillary sinuses were used to perform three SFE via transcrestal approach per sinus (36 elevations). Each sinus was randomly assigned to either the Sinus Crestal Approach (SCA) drill kit technique (experimental group) or the conventional osteotome technique (control group). During all phases of the surgery, the integrity of the sinus membrane was monitored through endoscopic examination.ResultsA significant difference was found in the incidence of perforation (p = 0.007) and vertical elevation height (p < 0.001) between the study groups, favoring the experimental group. A safety elevation threshold of 5 mm without bone graft and implant placement was estimated. A significant correlation was observed between the residual ridge height and the incidence of perforation (p < 0.001; OR = 0.51).ConclusionThe SCA drill kit may demonstrate superior osteotomy preparation and membrane elevation capabilities to the osteotome technique, and significantly when a 6â mm SFE is indicated. Residual ridge height and vertical elevation height are risk determinant factors.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147768/1/clr13388_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147768/2/clr13388.pd

Functional molecular mass of rat hepatic lipase in liver, adrenal gland and ovary is different

Lipoprotein lipase (LPL) is functionally active only as a dimer. It is also generally assumed that the highly homologous hepatic lipase functions as a dimer, but no clear evidence has been presented. A hepatic lipase-like activity, also indicated as L-type lipase, is present in adrenal and ovary tissues. This enzyme is thought to originate from the liver and to be identical to hepatic lipase. We determined the functional molecular mass of hepatic lipase in rat liver, adrenal gland and ovary by radiation inactivation, a method for determining the functional size of a protein without the need of prior purification. Samples were exposed to ionizing radiation at -135 degrees C. Hepatic lipase activity in liver homogenate showed a single exponential decay. The functional molecular mass was calculated to be 63 +/- 10 kDa. Hepatic lipase activity in adrenal homogenate was found to have a functional molecular mass of 117 +/- 16 kDa. The functional molecular masses of the lipases partially purified from rat liver perfusate, adrenal homogenate or ovarian homogenate showed the same pattern, a target mass for the liver enzyme of 56 +/- 6 kDa and a target mass of 117 +/- 14 kDa for the enzyme from adrenal gland or ovary. In Western blot analysis the mass of the structural units of hepatic lipase in liver was 57 kDa and in adrenal and ovary tissue 51 kDa. We conclude that the functional unit of hepatic lipase in the liver is a monomer. The enzyme in adrenal gland and ovary is different from the liver and the functional unit may be a dimer

Using periodontal staging and grading system as a prognostic factor for future tooth loss: A long- term retrospective study

BackgroundA new classification of periodontal diseases aimed to identify periodontal disease based on a multidimensional staging and grading system has been recently proposed. However, up to date, its prognostic predictive capability has not been investigated. The aim of this study was to assess if parameters included in the new classification were predictive of tooth loss after a long- term follow- up (>10 years) in patients with periodontitis.MethodsPatients presented with periodontitis at the University of Michigan between January 1966 and January 2004 were screened and categorized according to the new classification of periodontitis. Number/Reasons of teeth loss in patients who underwent at least one session/year of maintenance during the entire follow- up period were extracted and used to analyze the prognostic capabilities of variables (staging, grading, and Extent) included in the new classification.ResultsA total number of 292 patients with a mean follow- up of 289.7 ± 79.6 months were included. 31 (10.6%) patients were classified as Stage 1, 85 (29.1%) as Stage 2, 146 (50%) as Stage 3, and 30 (10.3%) as Stage 4. For grading, 34 (11.7%) were classified as Grade A, 193 (66.1%) as Grade B, and 65 (22.2%) as Grade C. Results of multilevel Cox regression analyses revealed a statistically significant association between stage (HR:3.73 between Stage 4 and Stage 1) and grade (HR: 4.83 between Grade C and Grade A) at baseline and periodontal related tooth loss, whereas no differences were detected for the extent of periodontitis.ConclusionThis study provides the initial evidence regarding the predictive ability of the new classification of periodontitis. Patients in either Stage 4 or Grade C showed a significantly higher periodontal- related tooth loss.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154975/1/jper10442_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154975/2/jper10442.pd

Influence of keratinized mucosa on the surgical therapeutical outcomes of peri-implantitis

AimTo assess the impact of keratinized mucosa (KM) width around dental implants on surgical therapeutic outcomes when treating peri- implantitis.Material and MethodsSurgically treated peri- implantitis implants were divided into two groups (KM width  .01). Between T1 and T2, no major differences were noted on PPD reduction, BOP and MBL changes between the two groups. GEE modelling demonstrated that MBL severity prior to surgical therapy was a better predictor for implant survival than KM width.ConclusionSurgical outcome in treating peri- implantitis was influenced by the severity of bone loss present at the time of treatment and not by the presence of KM at the time of treatment.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154633/1/jcpe13250.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154633/2/jcpe13250_am.pd

Considering the impact of situation-specific motivations and constraints in the design of naturally ventilated and hybrid buildings

A simple logical model of the interaction between a building and its occupants is presented based on the principle that if free to do so, people will adjust their posture, clothing or available building controls (windows, blinds, doors, fans, and thermostats) with the aim of achieving or restoring comfort and reducing discomfort. These adjustments are related to building design in two ways: first the freedom to adjust depends on the availability and ease-of-use of control options; second the use of controls affects building comfort and energy performance. Hence it is essential that these interactions are considered in the design process. The model captures occupant use of controls in response to thermal stimuli (too warm, too cold etc.) and non-thermal stimuli (e.g. desire for fresh air). The situation-specific motivations and constraints on control use are represented through trigger temperatures at which control actions occur, motivations are included as negative constraints and incorporated into a single constraint value describing the specifics of each situation. The values of constraints are quantified for a range of existing buildings in Europe and Pakistan. The integration of the model within a design flow is proposed and the impact of different levels of constraints demonstrated. It is proposed that to minimise energy use and maximise comfort in naturally ventilated and hybrid buildings the designer should take the following steps: 1. Provide unconstrained low energy adaptive control options where possible, 2. Avoid problems with indoor air quality which provide motivations for excessive ventilation rates, 3. Incorporate situation-specific adaptive behaviour of occupants in design simulations, 4. Analyse the robustness of designs against variations in patterns of use and climate, and 5. Incorporate appropriate comfort standards into the operational building controls (e.g. BEMS)

Data Provisioning for the Object Modeling System (OMS)

The Object Modelling System (OMS) platform supports initiatives to build or re - factor agro - environmental models and deploy them in different business contexts as model services on cloud computing platforms. Whether traditional desktop, client - server, or emerging cloud deployments, success especially at the enterprise level relies on stable and efficient data provisioning to the models. In this paper we describe recent experience and trends with tools and services to supply data for model inputs. Solutions range from simple pre - processing tools to data services deployed to cloud platforms. Also, systematic, sustained data stewardship and alignment with standards organizations impart stability to data provisioning efforts