Implant cantilever beam torque-limiting devices are affected by parallax, which may result in measurement read error. The overread or underread of the true target torque value could lead to premature ...failure of the screw joint of a dental implant.
The purpose of this in vitro study was to determine the effect of the operator’s viewing angle relative to the cantilever beam and measurement reading scale when the torque-limiting device is actioned toward or away from the operator.
A beam torque wrench (Nobel Biocare USA) was used with the cantilever beam position fixed by using a wedge to read 32 Ncm on the marker arm. It was suspended in a vertical position relative to a digital single-lens reflex camera set at a fixed distance of 48 cm from the marker reading. The camera was rotated in 10-degree increments clockwise and counterclockwise relative to the cantilever beam reading, starting perpendicular to the marker. Photographs were recorded at each angle. Percentage measurement read error was calculated from dimensions of the cantilever beam torque device, including the beam diameter, distance from the marker arm, and the incremental marks on the measurement scale. Data were analyzed descriptively to determine the differences after comparison with the International Organization for Standardization (ISO) 6789-1:2017 recommendations.
Photographs compared beam position relative to the 32-Ncm marker. The beam diameter was recorded as 1.5 mm, corresponding to approximately 5 Ncm. The distance between the marker arm and center of the beam was 0.08 mm. Percentage errors were greatest at lower torque values and increased relative to the viewing angle. Photographs showed that instrument overread was most likely to occur as the beam was moved away from the operator, which would result in potential undertightening unless compensated for. Underread was noted when the beam was pulled toward the operator.
To prevent measurement read error when using an implant cantilever beam torque-limiting device, the operator should be positioned as close to a perpendicular viewing angle to the cantilever beam as possible. Viewing from an angle greater than 10 degrees from the perpendicular should be avoided for torque values less than 15 Ncm. For screws tightened between 25 Ncm and 35 Ncm, the viewing angle should be less than 30 degrees so that the applied torque is within the maximum deviation of the target torque value set by the ISO 6789-1:2017 recommendations.
Elevated fasting blood glucose (FBG) is associated with increased risks of developing type 2 diabetes (T2D) and cardiovascular-associated mortality. G6PC2 is predominantly expressed in islets, ...encodes a glucose-6-phosphatase catalytic subunit that converts glucose-6-phosphate (G6P) to glucose, and has been linked with variations in FBG in genome-wide association studies. Deletion of G6pc2 in mice has been shown to lower FBG without affecting fasting plasma insulin levels in vivo. At 5 mM glucose, pancreatic islets from G6pc2 knockout (KO) mice exhibit no glucose cycling, increased glycolytic flux, and enhanced glucose-stimulated insulin secretion (GSIS). However, the broader effects of G6pc2 KO on β-cell metabolism and redox regulation are unknown. Here we used CRISPR/Cas9 gene editing and metabolic flux analysis in βTC3 cells, a murine pancreatic β-cell line, to examine the role of G6pc2 in regulating glycolytic and mitochondrial fluxes. We found that deletion of G6pc2 led to ∼60% increases in glycolytic and citric acid cycle (CAC) fluxes at both 5 and 11 mM glucose concentrations. Furthermore, intracellular insulin content and GSIS were enhanced by approximately two-fold, along with increased cytosolic redox potential and reductive carboxylation flux. Normalization of fluxes relative to net glucose uptake revealed upregulation in two NADPH-producing pathways in the CAC. These results demonstrate that G6pc2 regulates GSIS by modulating not only glycolysis but also, independently, citric acid cycle activity in β-cells. Overall, our findings implicate G6PC2 as a potential therapeutic target for enhancing insulin secretion and lowering FBG, which could benefit individuals with prediabetes, T2D, and obesity.
The practical utility of ionic liquids (ILs) makes the absence (heretofore) of reported examples from nature quite puzzling, given the facility with which nature produces many other types of exotic ...but utilitarian substances. In that vein, we report here the identification and characterization of a naturally occurring protic IL. It can be formed during confrontations between the ants S. invicta and N. fulva. After being sprayed with alkaloid‐based S. invicta venom, N. fulva detoxifies by grooming with its own venom, formic acid. The mixture is a viscous liquid manifestly different from either of the constituents. Further, we find that the change results as a consequence of formic acid protonation of the N centers of the S. invicta venom alkaloids. The resulting mixed‐cation ammonium formate milieu has properties consistent with its classification as a protic IL.
Crazy about ionic liquids: Throughout the southern United States, the invasive ant species S. invicta (fire ants) and N. fulva (tawny crazy ants) vie for resources. During confrontations, N. fulva is sprayed by S. invicta with a lipophilic, piperidine‐based venom. The former defeats this chemical attack by grooming with its own venom, formic acid. The combination forms a protic ionic liquid, which is the first naturally occurring ionic liquid to be reported.
Background. In 2000, results of a multinational trial demonstrated that a 2-month course of rifampin and pyrazinamide (RZ) was as effective as isoniazid (INH) in reducing tuberculosis in human ...immunodeficiency virus (HIV)—infected individuals with latent tuberculosis infection (LTBI). After the release of new guidelines, the Centers for Disease Control and Prevention received reports of severe hepatotoxicity associated with the use of the RZ regimen for the treatment of LTBI in the general population. To better understand the occurrence of hepatotoxicity in an HIV-infected population, we conducted a more detailed analysis of the liver function test results obtained in the multinational trial of RZ. Methods. At study entry, patients were required to have a bilirubin level of ⩽2.5 mg/dL and both an aspartate aminotransferase (AST) level and an alkaline phosphatase level of ⩽5 times the upper limit of normal. Patients with acute hepatitis were excluded. At months 1 and 2 of the study, all patients had bilirubin and AST levels measured. Results. There was no difference between the RZ and INH groups with regard to AST level or bilirubin level at baseline. An increase in the AST level of ⩾40 U/L was associated with the use of INH and older age; and an increase in the bilirubin level of ⩾0.5 mg/dL was associated with the use of RZ, male sex, and nonwhite race (P < .05). An absolute AST level of >250 U/L occurred in 12 of 745 INH recipients and in 15 of 721 RZ recipients (P = .56), and an absolute bilirubin level of >2.5 mg/dL occurred in 5 of 743 INH recipients and 13 of 718 RZ recipients (P = .06). Conclusions. These data demonstrate very little liver injury associated with either INH or RZ in the HIV-infected subjects, leaving unclear the reasons for serious RZ-related liver damage in the general population.
R. M. O'Brien and D. K. Granner
Department of Molecular Physiology and Biophysics, Vanderbilt University Medical School, Nashville, Tennessee, USA.
While insulin has long been known to modulate ...intracellular metabolism by
altering the activity or intracellular location of various enzymes, it is
only in the past 10 years that the regulation of gene expression by insulin
has been recognized as a major action of this hormone. This review
principally focuses on the regulation of gene transcription by insulin,
although recent progress in the understanding of insulin-regulated mRNA
stability and translation is also summarized. The identification of
cis-acting elements and associated trans-acting factors through which
insulin either increases or decreases the transcription of specific genes
is reviewed in detail. Recent advances in the understanding of the
mechanisms of insulin signaling are discussed in the context of
insulin-regulated gene transcription, and emphasis is placed on the gaps
that remain between the upstream signaling molecules and the downstream
trans-acting factors whose binding/transactivation potential is ultimately
regulated. Finally, potential gene expression defects that may contribute
to the pathophysiology of non-insulin-dependent diabetes mellitus and
hypertriglyceridemia are considered.
The potential for burnout among workers in developmental disabilities has been a frequent concern. In the present study, self-reported levels of burnout (Maslach Burnout Inventory scores) were ...correlated with measures of staff activity and commonly cited behavioral effects of burnout. Seventy-nine direct care staff from five facilities serving the developmentally disabled were given the MBI and a brief questionnaire. Data were also collected on absenteeism and tardiness and a time sampling procedure was employed to assess staff activity. Of 102 correlations between the MBI and demographic, self-report, and behavioral measures, only 5 were statisticaly significant at the .05 level. Of 55 correlations among 11 staff activities, 22 were statistically significant. The activity correlations revealed two distinct patterns. The two activities involving positive direct client contact were negatively correlated with the four activities involving negative client contact or the absence of client contact. Staff who engaged in much negative client contact were also likely to avoid client contact and engage in little positive client contact. Staff exhibiting such behavior patterns would be described as burned out with respect to job performance. Given the limited relationship between self-reports of burnout and staff performance, it would seem prudent to include some direct observation of staff behavior in burnout research.
The World Series of Quality Control Kortick, Steven A.; O'brien, Richard M.
Journal of organizational behavior management,
07/1996, Letnik:
16, Številka:
2
Journal Article
Recenzirano
Internal competition has been a part of many interventions in organizational behavior management as well as in nonbehavioral management programs. Often competition is implicit in feedback programs. ...The use of internal competition is endorsed by some theorists and questioned by others. In the present study, formal competition was used as an intervention to improve quality control in a package delivery company. In this industry, speed and accuracy of package delivery are critical to company success. For uie major companies in the industry, these outcomes are dependent upon the quality of sorting and loading at central loading facilities located throughout the United States. In order to improve quality control in sorting and loading, a competitive program of feedback and positive reinforcement was implemented using a baseball analog system. Extant work groups were paired in daily games in which points were scored based on company quality control measures. Fourteen teams were divided into leagues and divisions leading to playofts and a world series. The program demonstrated quality increases, prompting management to replace the local program with a regional competition between faculties. These data suggest that internal competition can be a potent intervention to improve quality control.
We examined the biology of AMPA/kainate-induced motor neuron degeneration using dissociated spinal cord cultures and motor neuron-specific antibodies which enable characterization of individual motor ...neurons in culture. Cobalt, which is thought to pass through Ca2+-permeable AMPA/kainate receptors following kainate exposure, labeled motor neurons in spinal cord cultures. The analysis of AMPA subunit distribution in dissociated motor neurons revealed a unique pattern of glutamate receptor (GluR) subunits in those cells; the GluR1 subunit was found in all spinal cord neurons, but the GluR2 subunit was not found in identified dissociated motor neurons. These data suggest that selective sensitivity of motor neurons to non-NMDA receptor activation is due, at least in part, to the presence of Ca2+-permeable AMPA/kainate receptors.
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