Nevin Manimala

Eur J Dent. 2021 Jul 7. doi: 10.1055/s-0041-1725575. Online ahead of print.

ABSTRACT

OBJECTIVES: This study aimed to assess the relation between the insertion torque and implant stability quotient (ISQ recorded immediately and 6 months after implant placement).

MATERIALS AND METHODS: Twenty-five patients over the age of 18 years were selected for this study. One implant was placed per patient after tooth extraction. The implant site needed 15 mm in height and 8 mm in width. All implants had the same size (11.5 × 3.75 mm) and brand (Hexagonal Morse cone, DSP Biomedical). The insertion torque (Ncm) and resonance frequency analysis (ISQ value) (Osstell Mentor) were used to assess the primary stability (on the day of surgery). After 6 months, ISQ value was used to assess the secondary stability of each implant.

STATISTICAL ANALYSIS: The insertion torque data were correlated with ISQ measurements by using Pearson’s correlation. The significance level was 5%.

RESULTS: There was a positive correlation between insertion torque and initial ISQ (correlation: 0.457; p = 0.022); however, no correlation was found between insertion torque and final ISQ (p = 0.308).

CONCLUSION: The present study demonstrated that there is a positive correlation between the insertion torque and the initial ISQ. Therefore, the higher the insertion torque, the higher the initial ISQ (or vice versa).

PMID:34233364 | DOI:10.1055/s-0041-1725575

Eur J Dent. 2021 Jul 7. doi: 10.1055/s-0041-1729457. Online ahead of print.

ABSTRACT

OBJECTIVE: The study aimed to evaluate the bond strength between lithium disilicate ceramic and resinous cement when silane (Prosil, FGM) was applied in different amounts of layers under heating or not.

MATERIALS AND METHODS: Sixty IPS E-max CAD ceramic (Ivoclar) was used. They were conditioned with 10% hydrofluoric acid for 20 seconds. The samples were distributed in six groups (n = 10): 1Sil, 1 layer of silane without heating; 1SilAq, 1 layer of silane with heating; 2Sil, 2 layers without heating; 2SilAq, 2 layers with heating; 3Sil, 3 layers without heating; and 3SilAq, 3 layers with heating. After each layer, a jet of cold air was applied for 20 seconds in groups 1Sil, 2Sil, 3Sil, and jet of hot air (50°C) in groups 1SilAq, 2SilAq, and 3SilAq. Subsequently, an adhesive layer was applied, and fourcylinders were made on the ceramic with a resin cement AllCemVeneer and photoactivated for 20 seconds. The samples were stored at 37°C for 24 hours and analyzed to the microshear test at EMIC.

STATISTICAL ANALYSIS: Data were submitted to ANOVA and Tukey’s test (α = 0.05).

RESULTS: The results showed that there was no statistical interaction between the factors studied. The “heating” factor was not statistically significant; however, the “silane layers” factor showed differences between groups. The analysis of the results showed that the use of one (66%) or two layers (67%) of silane regardless of heating, produced higher values of bond strength, when compared with the group of three layers (62%).

CONCLUSION: The use of silane with one or two layers provided a greater bond strength between lithium disilicate ceramic and resinous cement and that the heating did not influence the results.

PMID:34233363 | DOI:10.1055/s-0041-1729457

J Am Podiatr Med Assoc. 2021 Jul 6:20-146. doi: 10.7547/20-146. Online ahead of print.

ABSTRACT

BACKGROUND: To evaluate clinicians’ compliance to follow national guidelines for tetanus vaccination prophylaxis in high-risk foot patients.

METHODS: We retrospectively evaluated 114 consecutive patients between June 2011 and March 2019 who presented with a foot infection resulting from a puncture injury through the emergency department. Eighty-three patients had diabetes mellitus and 31 patients did not have diabetes mellitus. Electronic medical records were used to collect a broad range of study data on patient demographics, previous medical history, previous tetanus immunization history and tetanus status upon presentation to the emergency department (ED), peripheral arterial disease, sensory neuropathy, laboratory values, and clinical / surgical outcomes.

RESULTS: 46.5% of the patients who presented to the ED with a puncture wound did not have up-to-date tetanus immunization. Of those patients, 79.2% received a tetanus-containing vaccine booster, 3.8% received intramuscular tetanus immunoglobulins (TIG), 3.8% received both tetanus-containing vaccine booster and TIG, and 20.8% received no form of tetanus prophylaxis. When comparing data between patients with and without diabetes, there were no statistical significant differences in tetanus prophylaxis.

CONCLUSION: Guidelines for tetanus prophylaxis amongst high-risk foot patients in this study center are not followed in all patients. Patients with DM are at high risks of exposure to tetanus, we recommend physicians to take a detailed tetanus immunization history and vaccinate them if tetanus history is unclear.

PMID:34233358 | DOI:10.7547/20-146

Eur J Public Health. 2021 Jun 3:ckab081. doi: 10.1093/eurpub/ckab081. Online ahead of print.

ABSTRACT

BACKGROUND: Early diagnosis of human papillomavirus (HPV) associated oropharyngeal cancer (OPC) is associated with improved survival. To achieve early diagnosis, it might be beneficial to increase awareness of the link between HPV and OPC. This increase of awareness could also be an important way to increase vaccination rates. The aim of our study was to explore the current public knowledge in the Netherlands regarding the association of HPV with OPC.

METHODS: An online cross-sectional survey was used and sent by the company Flycatcher Internet Research to 1539 of their panel members. Data were analyzed statistically by gender, age, educational level and the participants’ use of alcohol and tobacco.

RESULTS: The response rate was 68% (1044 participants). Our data revealed that 30.6% of the participants had heard of HPV. There was a knowledge gap regarding HPV in males (P < 0.001), people older than 65 years (P < 0.001), people with low education level (P < 0.001) and current smokers (P < 0.001). Of the respondents who had heard of HPV, only 29.2% knew of the association between HPV and OPC. We also found that only 49.7% of the population knew of the existence of an HPV vaccine.

CONCLUSIONS: The results of this survey indicate that the public awareness of HPV and the association of HPV with OPC is lacking. Interventions to increase awareness of HPV and its association with non-cervical cancer should be considered. This might help to increase the HPV vaccine uptake both for girls and boys and earlier diagnosis of this disease leading to improved survival.

PMID:34233355 | DOI:10.1093/eurpub/ckab081

Phys Med Biol. 2021 Jul 7. doi: 10.1088/1361-6560/ac1246. Online ahead of print.

ABSTRACT

PURPOSE: Electronic portal image devices (EPIDs) have been investigated previously for beams-eye view (BEV) applications such as tumor tracking but are limited by low contrast-to-noise ratio (CNR) and detective quantum efficiency (DQE). A novel multilayer imager (MLI), consisting of four stacked flat-panels was used to measure improvements in fiducial tracking during liver stereotactic body radiation therapy (SBRT) procedures compared to a single layer EPID.

METHODS: The prototype MLI was installed on a clinical TrueBeam linac in place of the conventional DMI single-layer EPID. The panel was extended during volumetric modulated arc therapy SBRT treatments in order to passively acquire data during therapy. Images were acquired for six patients receiving SBRT to liver metastases over two fractions each, one with the MLI using all 4 layers and one with the MLI using the top layer only, representing a standard EPID. The acquired frames were processed by a previously published tracking algorithm modified to identify implanted radiopaque fiducials. Truth data was determined using respiratory traces combined with partial manual tracking. Results for 4- and 1-layer mode were compared against truth data for tracking accuracy and efficiency. Tracking and noise improvements as a function of gantry angle were determined.

RESULTS: Tracking efficiency with 4-layers improved to 82.8% versus 58.4% for the 1-layer mode, a relative improvement of 41.7%. Fiducial tracking with 1-layer returned a root mean square error (RMSE) of 2.1mm compared to 4-layer RMSE of 1.5mm, a statistically significant (p<0.001) improvement of 0.6mm. The reduction in noise correlated with an increase in successfully tracked frames (r=0.913) and with increased tracking accuracy (0.927).

CONCLUSION: Increases in MV photon detection efficiency by utilization of a multi-layer imager (MLI) results in improved fiducial tracking for liver SBRT treatments. Future clinical applications utilizing BEV imaging may be enhanced by including similar noise reduction strategies.

PMID:34233309 | DOI:10.1088/1361-6560/ac1246

J Neural Eng. 2021 Jul 7. doi: 10.1088/1741-2552/ac123f. Online ahead of print.

ABSTRACT

OBJECTIVE: Motor imagery is the mental simulation of movements. It is acommon paradigm to design Brain-Computer Interfaces (BCI) that elicits the modulation of brain oscillatory activity similar to real, passive and induced movements. In this study, we used peripheral stimulation to provoke movements of one limb during the performance of motor imagery tasks. Unlike other works, in which induced movements are used to support the BCI operation, our goal was to test and improve the robustness of motor imagery based BCI systems to perturbations caused by artificially generated movements.

APPROACH: we performed a BCI session with ten participants who carried out motor imagery of three limbs. In some of the trials, one of the arms was moved by neuromuscular stimulation. We analysed 2-class motor imagery classifications with and without movement perturbations. We investigated the performance decrease produced by these disturbances and designed different computational strategies to attenuate the observed classification accuracy drop.

MAIN RESULTS: when the movement was induced in a limb not coincident with the motor imagery classes, extracting oscillatory sources of the movement imagination tasks resulted in BCI performance being similar to the control (undisturbed) condition; when the movement was induced in a limb also involved in the motor imagery tasks, the performance drop was significantly alleviated by spatially filtering out the neural noise caused by the stimulation. We also show that the loss of BCI accuracy was accompanied by weaker power of the sensorimotor rhythm. Importantly, this residual power could be used to predict whether a BCI user will perform with sufficient accuracy under the movement disturbances.

SIGNIFICANCE: We provide methods to ameliorate and even eliminate afferent disturbances during the performance of motor imagery tasks. This can help improving the reliability of current motor imagery based BCI systems.

PMID:34233305 | DOI:10.1088/1741-2552/ac123f

J Phys Condens Matter. 2021 Jul 7. doi: 10.1088/1361-648X/ac1239. Online ahead of print.

ABSTRACT

The calculated defect corrections to the polarization and dielectric functions for Bloch electrons in quantum wells are presented. These results were employed to derive the first two moment equations from the Boltzmann transport theory and then applied to explore the role played by defects on the magneto-transport of Bloch electrons. Additionally, we have derived analytically the inverse momentum-relaxation time and mobility tensor for Bloch electrons by making use of the screened defect-corrected polarization function. Based on quantum-statistical theory, we have investigated the defect capture and charging dynamics by employing a parameterized physics-based model for defects to obtain defect wave functions. Both capture and relaxation rates, as well as the density for captured Bloch electrons, were calculated self-consistently as functions of temperature, doping density and chosen defect parameters. By applying the energy-balance equation, the number of occupied energy levels and the chemical potential of defects were determined, with which the transition rate for defect capturing was obtained. By applying these results, the defect energy-relaxation, capture and escape rates, and Bloch-electron chemical potential were calculated self-consistently for a non-canonical subsystem of Bloch electrons. At the same time, the energy- and momentum-relaxation rates of Bloch electrons, as well as the current suppression factor, were also investigated quantitatively. By combining all these results, the temperature dependence of the Hall and longitudinal mobilities was presented for Bloch electrons in either single- or multi-quantum wells.

PMID:34233302 | DOI:10.1088/1361-648X/ac1239

Bioinspir Biomim. 2021 Jul 7. doi: 10.1088/1748-3190/ac1248. Online ahead of print.

ABSTRACT

Dependence on constant availability to an external localization service is often unreliable and infeasible in mobile robots. In this paper, we take inspiration from a continuous fish motion model, the Persistent Turning Walker (PTW), to devise a strategy which is able to achieve 2D and 3D coverage in an unknown environment in the absence of a localization service, such as a Global Positioning System (GPS). This is achieved by converting the continuous-time dynamical system into a Discrete-Time Markov Chain (DTMC) which is then shown to exhibit strongly connected properties that are verifiable through numerical methods. The aforementioned proposed framework can also be used to study the continuous-time dynamics of other biological systems and evaluate their properties. The performance of the PTW model is also compared with two existing random search strategies, Simple Random Walks (SRW) and Correlated Random Walks (CRW) by using analytical bounds, simulation results, and statistical tests. The simulation results show that the proposed PTW algorithm covers a given search-space at a faster rate compared to the CRW and SRW models. Hence, the PTW may be effectively used as a coverage strategy by mobile robots in underwater or underground environments where the availability of a GPS cannot be guaranteed at all times.

PMID:34233301 | DOI:10.1088/1748-3190/ac1248

Aging (Albany NY). 2021 Jul 7;13. doi: 10.18632/aging.203275. Online ahead of print.

ABSTRACT

Individuals with depression, on average, die prematurely, have high levels of physical comorbidities and may experience accelerated biological ageing. A greater understanding of age-related changes in physiology could provide novel biological insights that may help inform strategies to mitigate excess mortality in depression. We used generalised additive models to examine age-related changes in 15 cardiovascular, body composition, grip strength and lung function measures, comparing males and females with a lifetime history of depression to healthy controls. The main dataset included 342,393 adults (mean age = 55.87 years, SD = 8.09; 52.61% females). We found statistically significant case-control differences for most physiological measures. There was some evidence that age-related changes in body composition, cardiovascular function, lung function and heel bone mineral density followed different trajectories in depression. These differences did not uniformly narrow or widen with age and differed by sex. For example, BMI in female cases was 1.1 kg/m² higher at age 40 and this difference narrowed to 0.4 kg/m² at age 70. In males, systolic blood pressure was 1 mmHg lower in depression cases at age 45 and this difference widened to 2.5 mmHg at age 65. These findings suggest that targeted screening for physiological function in middle-aged and older adults with depression is warranted to potentially mitigate excess mortality.

PMID:34233295 | DOI:10.18632/aging.203275

Clin Nutr. 2021 May 31;40(7):4674-4684. doi: 10.1016/j.clnu.2021.05.015. Online ahead of print.

ABSTRACT

BACKGROUND & AIMS: Obesity and low muscle mass are associated with worse outcomes of colorectal cancer patients. We conducted a controlled trial to study the impact of a ketogenic diet (KD) based on natural foods versus an unspecified standard diet (SD) on body composition in rectal cancer patients undergoing radiotherapy.

METHODS: Patients with non-metastasized rectal cancer were allocated to either the KD (N = 24) or the SD (N = 25) group during radiotherapy. Body composition was measured weekly by bioimpedance analysis and analyzed using linear mixed effects models. Pathologic response in patients undergoing neoadjuvant treatment was evaluated at the time of surgery.

RESULTS: A total of 18 KD and 23 SD patients completed the study and were eligible for analysis. The SD group experienced no noteworthy changes in any body composition parameter. In contrast, patients in the KD group lost significant amounts of body weight and fat mass, averaging 0.5 and 0.65 kg/week (p < 0.0001). There was a rapid loss of intracellular water consistent with initial intramuscular glycogen and water depletion, but skeletal muscle tissue was conserved. Pathological tumor responses were somewhat greater in the KD group, with a larger mean Dworak regression grade (p = 0.072) and larger percentage of near-complete (yT0N0 or yT1N1) responses (43 versus 15%, p = 0.116) that almost reached statistical significance in intention-to-treat analysis (50% versus 14%, p = 0.018).

CONCLUSIONS: In rectal cancer patients undergoing curative radiotherapy, a KD significantly reduced body weight and fat mass while preserving skeletal muscle mass. We could demonstrate a trend for KDs contributing synergistically to pathological tumor response, a finding in line with preclinical data that warrants future confirmation in larger studies.

TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02516501, registered on August 06, 2015.

PMID:34233255 | DOI:10.1016/j.clnu.2021.05.015