Mechanical and Tribological Behavior of Mechanically Alloyed Ni-TiC Composites Processed via Spark Plasma Sintering

Titanium carbide (TiC) reinforced nickel (Ni) matrix composites were processed via mechanical alloying (MA) followed by spark plasma sintering (SPS) process. Mechanical alloying has gained special attention as a powerful non-equilibrium process for fabricating amorphous and nanocrystalline materials, whereas spark plasma sintering (SPS) is a unique technique for processing dense and near net shape bulk alloys with homogenous microstructure. TiC reinforcement varied from 5 to 50 wt.% into nickel matrix to investigate its effect on the microstructure and mechanical behavior of Ni-TiC composites. All Ni-TiC composites powder was mechanically alloyed using planetary high energy ball mill with 400 rpm and ball to powder ratio (BPR) 15:1 for 24 h. Bulk Ni-TiC composites were then sintered via SPS process at 50 MPa pressure and 900–1200 °C temperature. All Ni-TiC composites exhibited higher microhardness and compressive strength than pure nickel due to the presence of homogeneously distributed TiC particles within the nickel matrix, matrix grain refinement, and excellent interfacial bonding between nickel and TiC reinforcement. There is an increase in Ni-TiC composites microhardness with an increase in TiC reinforcement from 5 to 50 wt.%, and it reaches the maximum value of 900 HV for Ni-50TiC composites.     

Guidelines for prevention of hospital acquired infections

These guidelines, written for clinicians, contains evidence-based recommendations for the prevention of hospital acquired infections Hospital acquired infections are a major cause of mortality and morbidity and provide challenge to clinicians. Measures of infection control include identifying patients at risk of nosocomial infections, observing hand hygiene, following standard precautions to reduce transmission and strategies to reduce VAP, CR-BSI, CAUTI. Environmental factors and architectural lay out also need to be emphasized upon. Infection prevention in special subsets of patients - burns patients, include identifying sources of organism, identification of organisms, isolation if required, antibiotic prophylaxis to be used selectively, early removal of necrotic tissue, prevention of tetanus, early nutrition and surveillance. Immunodeficient and Transplant recipients are at a higher risk of opportunistic infections. The post tranplant timetable is divided into three time periods for determining risk of infections. Room ventilation, cleaning and decontamination, protective clothing with care regarding food requires special consideration. Monitoring and Surveillance are prioritized depending upon the needs. Designated infection control teams should supervise the process and help in collection and compilation of data. Antibiotic Stewardship Recommendations include constituting a team, close coordination between teams, audit, formulary restriction, de-escalation, optimizing dosing, active use of information technology among other measure. The recommendations in these guidelines are intended to support, and not replace, good clinical judgment. The recommendations are rated by a letter that indicates the strength of the recommendation and a Roman numeral that indicates the quality of evidence supporting the recommendation, so that readers can ascertain how best to apply the recommendations in their practice environments.     

Comparison of post-operative ICU sedation between dexmedetomidine and propofol in Indian population

Context:

Critically ill patients requiring mechanical ventilation frequently need sedatives and analgesics to facilitate their care. Dexmedetomidine, a short-acting alpha-2-agonist, possesses anxiolytic, anesthetic, hypnotic, and analgesic properties.

Aims:

The objective of this study was to evaluate the efficacy and safety of dexmedetomidine in comparison to propofol in the management of sedation for post-operative intensive care unit (ICU) patients, as a sedative agent.

Settings and Design:

Teaching hospital, A phase III, prospective, open, randomized and comparative.

Materials and Methods:

Thirty patients who were ambulatory and who required the post-operative mechanical ventilation or post-operative sedation were enrolled, in which 15 patients received Dexmedetomidine and remaining 15 patients received propofol. All these patients were treated for the period of 8 to 24 h.

Statistical Analysis Used:

Data were analyzed using Student''s t-test and Chi-square test. The value of P < 0.05 was considered as statistically significant.

Results:

Demographic data were comparable. Pulse rate, respiratory rate and blood pressure were comparable. Depth of sedation and extubation time were similar. To maintain analgesia throughout the study period, patients receiving propofol infusions required significantly more analgesics than patients receiving Dexmedetomidine.

Conclusions:

Dexmedetomidine appears to be a safe and acceptable ICU sedative agent when both the clinician''s and patient''s perspectives are considered.     

Fabrication of maxillary single complete denture in a patient with deranged mandibular occlusal plane: A case report

Construction of a single complete denture (SCD) is a challenging clinical situation especially when the opposing natural dentition is not in a normal plane of occlusion. Mal-aligned, tilted or supra-erupted teeth in the opposing arch are some of the problems that should be corrected to achieve a balanced occlusion in patients who require SCD. Achieving harmonious occlusal plane is a primary objective of any restorative procedure to facilitate natural mandibular movements and ease of mastication. Establishment of normal occlusal plane in opposite arch is pre-requisite to maintain the stability of the SCD. This clinical report describes restoration of mandibular teeth (with severe attrition and deranged occlusion) by establishing normal plane of occlusion with the help of custom made occlusal plane template (OPT) followed by construction of a complete denture in maxillary arch.     

Echocardiography for Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetic cardiomyopathy. The prevalence of phenotypic expression, in the absence of another systemic or cardiac disease causing increased left ventricular (LV) wall thickness, is estimated to be 1:500. The frequency of clinical presentation is far less, highlighting the need for a non-invasive diagnostic imaging tool. Echocardiography is readily available and allows for structural characterization and hemodynamic assessment of the hypertrophic heart and to screen patients at-risk for HCM, such as first degree relatives of affected individuals, and differentiate HCM from the athletic heart. Echocardiography can also be used to assess for anatomic abnormalities of the mitral valve apparatus that may exacerbate LV outflow track obstruction and to further risk stratify patients during exercise. Finally, echocardiography plays an integral role in guiding alcohol septal ablation procedures.     

Validation of the GRACE score for prognosis in Indian patients with acute coronary syndromes

AimTo validate the global registry of acute coronary events (GRACE) score in acute coronary syndromes (ACS) patients and study its angiographic correlation.Methods and resultsTwo-hundred and thirty-five ACS patients were studied for the combined endpoint of all-cause in-hospital mortality and non-fatal infarction/reinfarction. We tested the predictive accuracy of the composite GRACE score using the receiver operating characteristics (ROC) curve.Lower systolic blood pressure (SBP) (odds ratio [OR] 7.93, P=0.005), ST-segment deviation (OR 7.79, P=0.02) and cardiac biomarker positivity (OR > 6.52, P=0.01) were significantly associated with events. Serum creatinine > 1.4 mg/dL showed a trend towards statistical significance (OR 4.14, P=0.05), whereas age > 50 years (OR 3.62, P=not significant [NS]) and Killips class 4 (OR 2.71, P=NS) showed good association. The best value for predicting events was a GRACE score of > 217 and these patients were more likely to have double/triple vessel disease (P = 0.0009). The C statistic for the GRACE score was 0.75.ConclusionHigher GRACE score predicts in-hospital events and more severe angiographic coronary artery disease (CAD).     

The effects of daily consumption of grapefruit on body weight, lipids, and blood pressure in healthy, overweight adults

Folklore has suggested that consuming grapefruit may promote weight control. Sparse data exist to support this hypothesis, although there is some evidence of health promotion effects with regard to blood pressure control and modulation of circulating lipids. The aim of this randomized controlled trial was to prospectively evaluate the role of grapefruit in reducing body weight and blood pressure and in promoting improvements in the lipid profile in overweight adults (N = 74). Following a 3-week washout diet low in bioactive-rich fruits and vegetables, participants were randomized to either the control diet (n = 32) or daily grapefruit (n = 42) in the amount of one half of a fresh Rio-Red grapefruit with each meal (3× daily) for 6 weeks. No differences between group in weight, blood pressure, or lipids were demonstrated. Grapefruit consumption was associated with modest weight loss (-0.61 ± 2.23 kg, P = .097), a significant reduction in waist circumference (-2.45 ± 0.60 cm, P = .0002), and a significant reduction in systolic blood pressure (-3.21 ± 10.13 mm Hg, P = .03) compared with baseline values. Improvements were observed in circulating lipids of those consuming grapefruit, with total cholesterol and low-density lipoprotein significantly decreasing by -11.7 mg/dL (P = .002) and -18.7 mg/dL (P < .001), respectively, compared with baseline values. This study suggests that consumption of grapefruit daily for 6 weeks does not significantly decrease body weight, lipids, or blood pressure as compared with the control condition. However, the improvements in blood pressure and lipids demonstrated in the intervention group suggest that grapefruit should be further evaluated in the context of obesity and cardiovascular disease prevention.     

Comparative Evaluation of Bond Strengths of Different Core Materials with Various Luting Agents Used for Cast Crown Restorations

The coronal cast restoration continues to be used commonly to restore mutilated, endodontically treated teeth. The tensile bond strength of luting cements is of critical importance as many of failures are at the core and the crown interface. An invitro study with aim to evaluate and compare bond strengths of luting cements between different core materials and cast crowns. A total of 45 extracted identical mandibular second premolars were endodontically treated and divided into 3 groups of 15 each. Specimens in first group were restored with cast post and core (Group C), and specimens in second group were restored with stainless steel parapost and composite core material (Group B) and specimens in third group were restored with stainless steel parapost and glass ionomer core build (Group G). Standardized crown preparation was done for all the specimens to receive cast crowns. Each group was further divided into 3 subgroups and were cemented using 3 different luting cements namely, resin cement, polycarboxylate cement, glass ionomer cement (Type I). The samples of each subgroup (n = 5) were subjected to tensile testing using Universal Testing Machine at a crosshead speed of 2 mm/min till the dislodgement of crown from the core surface was observed. The bond strengths were significantly different according one way ANOVA (F-150.76 and p < 0.0000). The results of the study showed that the specimens cemented with resin cement in cast core, composite core and glass ionomer core exhibited significantly higher bond strengths as compared to specimens cemented with glass ionomer and polycarboxylate cement. Composite resin core and resin cement combinations were superior to all other cement and core combinations tested.