Regenerative Chatter Evaluation when Turning Nickel-based Superalloy GH4169 Using PCBN Cutting Tool

Vibration during machining operation is a major issue that lowers cutting operation efficiency. Usually high cutting forces are encountered during machining processes, consequently shortening cutting tool lifetime. Thus, the metal removable rate is reduced and a poor surface finish is produced. This issue can be overcome by selecting proper cutting parameters (cutting speed, feed, and depth of cut), especially when machining difficult-to-cut materials at high cutting speed. In this paper, a two-degrees-of-freedom turning vibration model is introduced to study the vibration mode of the system when nickel-based superalloy GH4169 is turned at varying cutting depths. The effect of varying the cutting depth on system vibration was simulated using the Matlab/Simulink software. In addition, the model was experimentally tested on a numerical controlled lathe machine. The stable limit cutting depth and the main vibration directions of the system chatter were the responses that were investigated. The results show that the simulation provided a reasonable approximation of the experimental results

The Value of a Longitudinal Human Immunodeficiency Virus Track for Medical Students: 10-Year Program Evaluation

We surveyed graduates of a longitudinal medical school human immunodeficiency virus curriculum to evaluate its impact. Respondents felt comfortable caring for people with human immunodeficiency virus (PWH) and found value from the curriculum regardless of ultimate career path. Programs like this contribute to the development of culturally sensitive clinicians comfortable caring for PWH

Analysis of Tooth Extraction Causes and Patterns

PURPOSE: The purpose of this study was to investigate the causes and patterns of extraction of permanent teeth in the targeted population. METHODS: The study was conducted for a period of 11 months. An especially designed form was used to record the causes for extraction of a permanent tooth. Further, it was analyzed for age, gender, education, occupation, smoking, tooth position, endodontic treatment, chewing, esthetics, needs replacement, type of existing prosthesis, and causes for extraction. The various causes which were considered to determine association with the tooth extraction were dental caries, periodontal problems, trauma, orthodontics, prosthodontic failures, endodontic failures, and others. RESULTS: The percentage of extractions was almost the same in males and females aged. Maximum extractions were noticed in 36–45 years of age group (32.5%). The presence of caries was observed to be the main reason for extraction (68.1%), followed by periodontal problems (17.6%) and orthodontic problems (4.8%). The most frequently extracted posterior teeth were first mandibular molar (22.2%), followed by the third maxillary molar (15.2%). CONCLUSION: Dental caries was found to be the most common reason for the extraction of teeth. Molar teeth were found to be the most frequently extracted, with an increased number of extracted first premolars as a result of orthodontic treatment. Maxillary teeth are extracted more than mandibular, mainly due to caries and periodontal problems

Modelling and simulation of electric drive vehicle based on space vector modulation technique and field oriented control strategy

Recently, the electric vehicle has emerged as a powerful platform for mitigating energy crisis and reducing environmental pollution in the transportation sector. The major drawbacks of electrically powered automobile that limits its competitiveness with the internal combustion engine counterpart are the vehicle driving range and battery energy capacity. Hence, limited energy storage warrants the need for an effective and efficient energy utilisation in the overall system. This paper uses Field Oriented Control algorithm and Space Vector Modulation technique to enhance and to optimise energy saving at the same time improve the vehicle induction motor efficiency. A simple electric vehicle drive with vehicle dynamic and tractive loads for motor driving load were modelled and simulated using Matlab/Simulink. Simulation results show that modelled vehicle speed satisfied the acceleration index for the electric vehicle

Methotrexate Encephalopathy: Two Cases in Adult Cancer Patients, Who Recovered with Pathophysiologically Based Therapy

Background/Objectives: Neurotoxicity is a serious and sometimes fatal adverse effect that can occur following methotrexate treatment. We describe two adult patients with hematological malignancies with methotrexate encephalopathy who recovered with dextromethorphan therapy. Results: Case 1 : A 24-year-old male with acute lymphoblastic leukemia developed the acute onset of bilateral facial weakness and slurred speech after his first treatment with high-dose intravenous methotrexate. The clinical scenario and a head magnetic resonance imaging supported a diagnosis of methotrexate encephalopathy. Treatment with dextromethorphan was coincident with recovery. Case 2 : A 65-year-old female with recurrent diffuse large B-cell lymphoma was treated with high- dose intravenous methotrexate. Two weeks after a cycle, she developed hypoactive delirium, marked lethargy, ocular ataxia, and a right-sided facial weakness. Within 2 days of starting dextromethorphan, there was improvement with clinical recovery. Conclusions: These two cases suggest that N -methyl d -aspartate receptor activation by homocysteine may play an important role in the pathogenesis of methotrexate neurotoxicity

The Association Between HIV-Related Stigma and HIV Outcomes: An Integrative Review

https://digitalcommons.unmc.edu/emet_posters/1032/thumbnail.jp

Effectiveness and Safety of Bictegravir/Emtricitabine/Tenofovir Alafenamide in Patients With HIV-1 Infection and Ongoing Substance Use Disorder: The BASE Study

BACKGROUND: People with human immunodeficiency virus (HIV) and substance use disorder (PWH/SUD) are at higher risk of nonadherence to antiretroviral therapy. Bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) exhibits high rates of efficacy with a favorable adverse event profile. The BASE study (NCT03998176) is a phase 4, single-arm study evaluating the effectiveness and safety of B/F/TAF among PWH/SUD. METHODS: Viremic (HIV RNA \u3e1000 copies/mL) PWH/SUD initiated B/F/TAF once daily for 48 weeks (W). The primary endpoint was proportion of participants with HIV RNA/mL at W24. Secondary endpoints were proportion of participants with HIV-1 RNA/mL at W48, safety, B/F/TAF adherence (dried blood spot [DBS] concentrations of emtricitabine triphosphate and tenofovir diphosphate [TFV-DP]), substance use (NIDA-ASSIST), and quality of life (SF-12). RESULTS: Forty-three participants were enrolled; 95% reported methamphetamine use. Median age was 38 (range, 21-62) years; 21% were female, 81% White, 14% Black, and 16% Hispanic. Thirty-two (74%) and 21 (49%) participants had HIV RNA/mL (intention-to-treat) at W24 and W48, respectively. Seven participants (16%) experienced confirmed virologic failure through W48; 1 developed emergent drug resistance (M184V). Fifteen participants (35%) experienced grade ≥3 adverse events. Five participants (12%) reported suicidal ideation; none resulted in discontinuation. Median DBS concentrations were representative of 5-6 doses/week (TFV-DP, 1603 fmol/punches). NIDA-ASSIST scores declined from baseline to W48 with methamphetamine use decreasing most (-7.9 points; -29%), and SF-12 physical/mental scores increased 1.2 and 7.6 points, respectively. CONCLUSIONS: B/F/TAF among a high-risk population of PWH/SUD resulted in an initial 72% viral suppression rate at W24 before dropping to 49% at W48 as retention declined. One participant developed emergent drug resistance (M184V)

Análise da correção atmosférica de imagens Landsat em estudo multitemporal na região de Mata Atlântica, Estado do Rio de Janeiro.

Multitemporal, remotely sensed data applied to land use land cover dynamic studies require radiometric correction of images, in addition to geometric correction. This allow the analysis of temporal variation of targets without the influence of others factors such as the atmospheric effects. This study aims to apply the dark-object subtraction technique to correct atmospheric effects and to analyze the results on multitemporal images of rivers Macacu and Caceribu watersheds, in Rio de Janeiro state, in Atlantic Forest region. Images without clouds from sensors TM/Landsat-5 and ETM+/Landsat-7 were selected for analysis of land use land cover dynamic of two periods: 1997 to 2002 and 2002 to 2007. The results indicated that the correction method did not reduce the atmospheric effects in a satisfactory manner. These effects continued to influence in any significant way in the spectral response of the targets. The major differences between the levels of gray of the corrected images were among the images of different sensors, indicating likely influence of the response of the sensors on the final results. o objetivo do presente trabalho é analisar o efeito da correção atmosférica aplicando método de subtração de nível de ci nza em imagens multitemporais da região das bacias hidrográficas dos rios Macacu e Caceribu, no Estado do Rio de Janeiro, em região de Mata Atlântica

Evaluation of Antibacterial Activity of Pine Tar on Periodontal Pathogenic Bacteria: An In Vitro Study

BACKGROUND: Periodontal pathogens play an important role in etiology and pathogenesis of periodontitis. Microbiological examination of sub gingival plaque is used at the present time in etiological research as well as in clinical treatment of periodontitis to select the appropriate antibiotic agent if indicated. Pine tar has been used for the treatment of various skin diseases. So the study was done to evaluate the effect of Pine Tar oil on bacteria isolated from periodontitis patients.METHODS: Plaque samples from volunteer patients were collected using sterile paper points. Robertson's Cooked Meat (RCM) medium was used for the transportation and cultivation of aerobic, microaerophilic, and anaerobic microorganisms.RESULTS: The result suggests the use of Pine tar oil for topical application in periodontal diseases. Disc diffusion analysis was sufficient enough to illustrate that 75 μl tar oil solution produced growth inhibition of microbial strains.CONCLUSION: Pine tar oil has become one of the important areas of research both in pharmaceutical and periodontal research, hence in vivo studies has to be carried out with various form of pine tar.&nbsp

Periodontal Treatment Practice and Referral Profile of General Dentists – A Cross-sectional Questionnaire Survey

BACKGROUND: Because of medical advancement, the mean age of the general population is increasing gradually. This increase in the mean age of patients has led to its implications on oral health. Hence, it is logical to assume an increase in the figure of referrals to specialists and the complexity of treatments provided. AIM: The aim of the survey was to assess the current status of periodontal treatment provided, awareness of referral profile, and criteria taken into consideration for the referral to the periodontist by general dentists. MATERIALS AND METHODS: This cross-sectional questionnaire study was conducted among 318 general dentists. The relevant work related to the status of periodontal procedures provided by dentists and their referral relationships were studied. The questionnaire consisting of six questions was designed. Descriptive statistics, including frequency distributions and measures of central tendency and Chi-square test, were used. RESULTS: The study showed that majority of the general dentists do non-surgical procedures by their own. However, around 85% of respondents did not provide surgical periodontal treatment by themselves. About 25% of the responding general dentists thought that they had inadequate education and experience in the field of periodontics which was a major reason for the referral to specialists. CONCLUSION: It was concluded that the general dentists are comfortable in carrying out the non-surgical procedures, but they had some reservations about the periodontal surgical procedures. Inadequate experience and facilities were the major reasons for the referral to periodontists. More of this type of study should be conducted to know the basic level of periodontal practices carried out among the general dentists and about the referral to the specialists