Singularities and the Finale of Black Hole Evaporation

In this essay we argue that once quantum gravitational effects change the classical geometry of a black hole and remove the curvature singularity, the black hole would not evaporate entirely but approach a remnant. In a modified Schwarzschild spacetime characterized by a finite Kretschmann scalar, a minimal mass of the black hole is naturally bounded by the existence of the horizon rather than introduced by hand. A thermodynamical analysis discloses that the temperature, heat capacity and the luminosity are vanishing naturally when the black hole mass approaches the minimal value. This phenomenon may be attributed to the existence of the minimal length in quantum gravity. It can also be understood heuristically by connecting the generalized uncertainty principle with the running of Newton's gravitational constant.Comment: 10 page

Recovery of Palm Carotene from Palm Oil and Hydrolysed Palm Oil Using Adsorption Column Chromatography

Crude palm oil (CPO) and crude palm olein (CPOlein) were hydrolysed with lipase from Candida Rugosa to produce free fatty acids (FFAs)- rich oil. The palm oil and hydrolysed palm oil were subsequently subjected to column chromatography process. Diaion HP-20 adsorbent was used for reverse phase column chromatography and the column temperature was kept at 50°C. Isopropanol (IPA) or ethanol (EtOH), and n-hexane were used as the first and second eluting solvents, respectively. The objective of hydrolysing the palm oil was to produce more polar FFA-rich oil in order to enhance the non-polar carotene to adsorb to the non-polar HP-20 adsorbent in the column chromatography. The results obtained showed that by hydrolysing CPO and CPOlein with lipase from Candida rugosa, gave 30- and 60-fold, respectively, of FFA production in the crude palm oil and crude palm olein in 8 h at 50°C. For column chromatographic process, using isopropanol or ethanol as the first eluting solvent, crude oil and hydrolysed oil showed the carotene recovery in fraction two (carotene-rich fraction) were about 36-37 and 90-96%, respectively. Over 90% of carotene recovery was obtained from hydrolysed palm oil reflecting an increase of about 55% over CPO. Response Surface Methodology (RSM) for optimisation of carotene recovery from hydrolysed palm olein (HCPOlein) in adsorption chromatography was carried out. The level and interaction of three independent variables was investigated: column temperature (50 to 60°C), oil loading (25 to 200 g), and mobile phase flow rate (6 to 60 mL/min) was investigated. Based on the response as percentage of carotene recovery from 50 g of HP-20 adsorbent, the optimum conditions were achieved at 200 g of oil loading, column temperature at 55°C, and flow rate at 33 mL/min. Up to 98% of carotene recovery was able to obtain under this condition. Interaction of oil-oil and oil-flow rate could enhance percentage of carotene recovery. On the other hand, oil and flow rate as single factors could significantly reduce percentage of carotene recovery. Oil loading as a single factor could positively influence amount of carotene adsorbed. However, flow rate as a single factor and oil-oil interaction could negatively influence amount of carotene adsorbed. The predicted results according to the model for both responses were closed to the observed responses for experiments. The mean of difference (MD) of the experimental and predicted data for percentage of carotene recovery, and amount of carotene adsorbed were very small, - 0.0067 and 0.0133, respectively. The probability (P) value showed no significant lackof- fit for both equations of this model. Laboratory-scale batch studies were carried out to investigate the use of synthetic polymer adsorbent, HP-20, for carotene extraction from CPOlein and HCPOlein. The adsorption of carotene was determined by several adsorption isotherm models such as Langmuir, Freundlich and Scatchard plots. The effect of temperature, contact time, adsobate concentration and the adsorbent mass were examined. The equilibrium data fitted with both Langmuir and Freundlich models with correlation coefficients >0.9.e concentration and the adsorbent mass wer

Outcomes and expenditures of clostridium difficile infection in pediatric solid organ transplant recipients

textThe main purpose of this study was to assess outcomes (i.e., inpatient mortality, transplant failure or rejection, colectomy, and hospital length of stay) of clostridium difficile infection (CDI) and the association of expenditures (i.e., charges and costs) and CDI in pediatric solid organ transplant (SOT) recipients. Data from the 2000, 2003, 2006, and 2009 Kids’ Inpatient Database (KID) files were used to identify events with SOT- related ICD-9-CM diagnosis codes. Logistic regression was used to assess the association of CDI and dichotomous outcome variables, while log-linked gamma regression models were used to assess the association of CDI and continuous outcome variables. Methods accounting for the complex survey sample design of the KID were used when performing all statistical analyses. The total number of pediatric SOT hospital events was 48,286. The overall prevalence of CDI for pediatric SOT hospitalizations was 1.76%. For SOT hospitalizations with CDI, inpatient mortality was 1.63%; the prevalence of transplant failure or rejection events was 27.71%; the prevalence of a colectomy was 4.86%. The median hospital length of stay was seven days; the median charge and cost for each hospitalization was $48,409 and$17,412, respectively. The results showed that CDI was not significantly associated with inpatient mortality or transplant failure/ rejection in pediatric SOT hospitalizations. SOT patients with CDI were 2.6 times more likely to have a colectomy than SOT patient without CDI. The mean hospital length of stay (LOS) for a SOT admission with CDI was approximately 2 times the mean LOS for a SOT admission without CDI. The mean charges and the mean costs for a SOT admission with CDI was approximately 2 times that for a SOT admission without CDI. In conclusion, CDI diagnoses were not significantly associated with higher inpatient mortality or transplant failure/ rejection for pediatric SOT hospitalizations. But CDI was significantly associated with a higher prevalence of a colectomy, longer hospital LOS, higher charges, and higher costs (all p<0.05). To avoid substantially higher expenditures and health care utilization, CDI in pediatric SOT recipients should be prevented when possible and promptly diagnosed and treated when it occurs.Pharmaceutical Science

Adherence to antidepressants and healthcare resource utilization and costs among medicare advantage beneficiaries with Parkinson’s disease and depression

Depression is the most common comorbid psychiatric disorder in patients with Parkinson’s disease (PD) and imposes a significant negative impact on PD. Studies have shown that antidepressants (ADs) may both treat depression and ameliorate its negative effects on PD. However, little has been reported regarding how improved adherence to antidepressants affects the outcomes among PD patients with depression. The purpose of this study was to examine antidepressant use patterns (adherence, persistence, switching, and combination therapy) and evaluate the associated healthcare utilization and costs in PD patients with comorbid depression. A retrospective cohort analysis using claims data from the Humana healthcare insurance plan (2007-2010) was conducted. Medicare Advantage with Prescription Drug (MAPD) Plan insured patients with ADs and a diagnosis of both depression and PD were identified and followed for one year. Healthcare resource utilization and costs were compared between adherent and non-adherent AD users while adjusting for demographic and clinical covariates. Adherence was defined as having at least 80 percent of AD coverage for the year, using proportion of days covered (PDC) calculations. A total of 856 PD patients initiating AD treatment were included. Less than half (N= 355 (41.5%) were considered adherent. The mean PDC (±SD) for antidepressants was 0.63 (± 0.31). The mean persistence (using a 30-day gap period) for antidepressants was 194 days. Having a regimen modification, (11% of patients had switching or combination therapy) was associated with a greater likelihood of being adherent (odds ratio = 2.97, 95% CI = [1.88, 4.68], p < 0.001) and a lower likelihood of discontinuation (hazard ratio = 0.63, 95% CI = [0.47, 0.84], p = 0.0016). After adjusting for covariates, adherent AD users had fewer all-cause and PD-related inpatient visits (all p < 0.05). Adherent AD users also had lower all-cause nursing facility, inpatient, emergency room (ER), and total costs (all p < 0.05) than non-adherent AD users. However, the results were no longer significant when assessing PD-related costs. In conclusion, regimen modification (switching, or combination therapy) to antidepressants was associated with better adherence and persistence in depressed PD patients. Adherent AD users had some lower healthcare utilization and costs than non-adherent AD users among depressed PD patients.Pharmaceutical Science

Partial Characterisation and Some Properties of a Thermophilic Bacterium Isolated from a Petroleum Reservoir in Sarawak, Malaysia

The hypertbermophilic bacteria (MRU5) was isolated from an oil-producing well in Sarawak. Malaysia. MRU5 is strictly anaerobic and was grown in enrichment media which were been degassed with CO2:N2 (80:20). By Gram and spore staining, MRU5 was found to be a gram negative, non-spore producing bacteria. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) revealed the shape of the bacteria to be irregular and coccoid which occurs singly, in pairs or clumps. The bacteria measures 0.75µm in diameter and is surrounded by an outer sheath coating. MRU5 was found to grow best at pH 7 and 10% salinity with the optimal temperature range of between 90°C to 100°C. MRU5 was grown in xylose, glucose, fructose, arabinose, lactose, and sucrose. From the results obtained, xylose was the most efficiently utilised fermentable carbon source. Growth of the microorganism is supported by yeast extract. End products such as organic acids and H2S were produced by fermentation of carbon sources but none of the tested solvents were produced. This microorganism is able to reduce oil viscosity by producing organic acids. This means that MRU5 has the potential to be ecologically important for enhancing oil recovery. The modified Gompertz equation was found to be appropriate to model the growth of bacterium MRU5 at different medium compositions and culture conditions

Feasibility and effect of para-right bundle branch pacing in patients with atrial fibrillation and complete atrioventricular block

Background: Chronic right ventricular apex (RVA) pacing can induce negative clinical effects. The aim of the present study was to compare RVA pacing with para-right bundle branch (para-RBB) pacing in terms of electrocardiogram (ECG) and echocardiographic (ECHO) features. Methods: Forty-one consecutive persistent atrial fibrillation patients with an indication for permanent pacing treatment due to complete atrioventricular block were randomly assigned to receive a screw-in lead either in the RVA (n = 22) or at the para-RBB (n = 19). Para-RBB pacing leads were located according to the RBB potential recorded by electrophysiology catheter. ECG was recorded before and after implantation. All patients underwent the pacemaker pro­gramming at 1 day, 6 months, 12 months and 24 months after implantation. ECHO examina­tion was performed during follow-up at 6, 12 and 24 months after implantation to assess the heart function and synchronism. Results: There was no significant difference in pacing lead parameters between para-RBB pacing group and RVA pacing group. Compared with RVA pacing group, the para-RBB pacing group obtained a narrower QRS complex, more synchronic ventricular systole, and less nega­tive effect on heart function (p &lt; 0.05). Conclusions: Para-RBB pacing has potential clinical benefits and may be a physiological pacing site.