160 research outputs found
Extraction of the essential oil of Aquilaria Malaccensis (gaharu) using hydro-distillation and solvent extraction methods
Agarwood oil is regarded as one of the most expensive natural products in the world due to the fragrance inducing compounds it contains. However, current studies on the chemical composition of agarwood essential oil are woefully lacking and this poses a threat to the agarwood industry. This research aims to identify the best extraction method for isolating gaharu essential oil and to create a list of compounds contained in a sample of grade C agarwood. In the present work, the composition of agarwood essential oil obtained through hydro-distillation and solvent extraction with acetone, dichloromethane and hexane as the solvents were analyzed for marker compound identification using gas chromatography-mass spectrometry (GC-MS). Studying another parameter of this experiment, the sample hydro-distillated in the lab was compared with industrial grade hydro-distillation to determine the difference in quality between industrial and lab scale hydro-distillation. Of the three solvents used, acetone eluted the highest number of compounds. The lab scale hydro-distillated sample eluted 34 compounds at a quality of 50% and above whereas the solvent extraction sample eluted 25 compounds. There was no significant difference found between lab scale and industrial scale hydro-distillation
Differences in peripheral noradrenergic function among actively drinking and abstinent alcohol-dependent individuals.
We examined whether excessive alcohol consumption was related to changes in plasma levels of noradrenaline (NA) and whether these changes recover following abstinence. We also explored whether there were differences in NA levels between Type I and Type II alcoholics and controls during active drinking and abstinence. Plasma concentrations of NA were determined in (1) 27 Caucasian men with alcohol dependence who were regularly drinking (active drinkers) within 24 hours of hospitalization, (2) 29 Caucasian alcohol-dependent men who were in remission (abstinent for a minimum of three months), and (3) 28 race- and gender-matched healthy controls. NA concentrations were significantly higher in actively drinking alcohol-dependent subjects compared to those in remission and controls. While Type I and Type II alcoholic individuals differed across clinical measures, NA levels were similar in the two subtypes. Both subtypes showed an elevation in NA levels during active drinking compared to controls, but NA levels did not differ between the two subtypes and controls during remission. The findings indicate that chronic exposure to alcohol may lead to disturbances in NA activity that may manifest in early abstinence. However, the changes in NA activity appears to normalize after a longer period of abstinence. Alterations in NA activity do not seem to be specific for Type I or Type II subtypes of alcoholism
Double-Blind, Multicenter, Prospective Randomized Study of Trospectomycin Vs. Clindamycin, Both With Aztreonam, in Non-Community Acquired Obstetric and Gynecologic Infections
Objective: The purpose of this study was to compare the clinical efficacy and safety of trospectomycin sulfate with that of clindamycin phosphate, both with aztreonam, for the treatment of obstetric and gynecologic infections
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Aqueous Multiphase Systems of Polymers and Surfactants Provide Self-Assembling Step-Gradients in Density
This Communication demonstrates the generation of over 300 phase-separated systemsâranging from two to six phasesâfrom mixtures of aqueous solutions of polymers and surfactants. These aqueous multiphase systems (MuPSs) form self-assembling, thermodynamically stable step-gradients in density using a common solvent, water. The steps in density between phases of a MuPS can be very small (ÎÏ â 0.001 g/cm3), do not change over time, and can be tuned by the addition of co-solutes. We use two sets of similar objects, glass beads and pellets of different formulations of Nylon, to demonstrate the ability of MuPSs to separate mixtures of objects by differences in density. The stable interfaces between phases facilitate the convenient collection of species after separation. These results suggest that the stable, sharp step-gradients in density provided by MuPSs can enable new classes of fractionations and separations based on density.Chemistry and Chemical BiologyEngineering and Applied Science
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Separation of Nanoparticles in Aqueous Multiphase Systems through Centrifugation
This paper demonstrates the use of aqueous multiphase systems (MuPSs) as media for rate-zonal centrifugation to separate nanoparticles of different shapes and sizes. The properties of MuPSs do not change with time or during centrifugation; this stability facilitates sample collection after separation. A three-phase system demonstrates the separation of the reaction products (nanorods, nanospheres, and large particles) of a synthesis of gold nanorods, and enriches the nanorods from 48 to 99% in less than ten minutes using a benchtop centrifuge.Chemistry and Chemical BiologyEngineering and Applied Science
Comparison of pretreatment characteristics and treatment outcomes for alcohol-, cocaine-, and multisubstance-dependent patients.
We investigated whether pretreatment characteristics and measures of outcome differed for alcohol-, cocaine-, and multisubstance-dependent patients receiving outpatient substance abuse treatment. One hundred and forty substance dependent individuals (32 alcohol, 76 cocaine, and 32 multisubstance) enrolled in a 12-week outpatient treatment program were compared across measures of addiction severity, personality, and treatment-readiness at admission. In-treatment, end-of-treatment and 9-month follow-up assessments of treatment outcome were then compared across the three groups. Outcome measures included reduction in problem severity, abstinence, retention, number of sessions attended, dropout, and counselor and patient ratings of treatment benefit. At admission, the multisubstance group had a higher proportion of positive urines, reported more severe drug, alcohol and psychiatric problems, and displayed higher impulsivity and anxiety scores than one or both of the other groups. However, multisubstance patients were more treatment ready in terms of adopting a total abstinence orientation than alcohol or cocaine patients. While a significant reduction in symptoms occurred for the total sample during treatment as well as at follow-up, comparisons of outcomes did not consistently favor any particular group. The three groups had equivalent improvements in eleven of fourteen during-treatment and five of seven follow-up measures. Despite pretreatment differences, in severity and treatment-readiness, outcomes were more similar than different for alcohol-, cocaine-, and multisubstance-dependent patients. Clinicians should be cautious about forecasting treatment-outcomes for addicted patients based on their primary substances of abuse
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Physical activity and risk of inflammatory bowel disease: prospective study from the Nursesâ Health Study cohorts
Objective: To examine the association between physical activity and risk of ulcerative colitis and Crohnâs disease. Design: Prospective cohort study. Setting: Nursesâ Health Study and Nursesâ Health Study II. Participants: 194 711 women enrolled in the Nursesâ Health Study and Nursesâ Health Study II who provided data on physical activity and other risk factors every two to four years since 1984 in the Nursesâ Health Study and 1989 in the Nursesâ Health Study II and followed up through 2010. Main outcome measure Incident ulcerative colitis and Crohnâs disease. Results: During 3 421 972 person years of follow-up, we documented 284 cases of Crohnâs disease and 363 cases of ulcerative colitis. The risk of Crohnâs disease was inversely associated with physical activity (P for trend 0.02). Compared with women in the lowest fifth of physical activity, the multivariate adjusted hazard ratio of Crohnâs disease among women in the highest fifth of physical activity was 0.64 (95% confidence interval 0.44 to 0.94). Active women with at least 27 metabolic equivalent task (MET) hours per week of physical activity had a 44% reduction (hazard ratio 0.56, 95% confidence interval 0.37 to 0.84) in risk of developing Crohnâs disease compared with sedentary women with 0.35). Conclusion: In two large prospective cohorts of US women, physical activity was inversely associated with risk of Crohnâs disease but not of ulcerative colitis
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Using Magnetic Levitation to Separate Mixtures of Crystal Polymorphs
Magnetische Levitation (MagLev) ist eine einfache Trennmethode fĂŒr Kristallpolymorphe mit Dichteunterschieden (ÎÏ) von nur 0.001â
gâcmâ3. FĂŒr vier organische Verbindungen wurden dichtebasierte Trennungen verschiedener kristalliner Formen gezeigt: 5-Methyl-2-[(2-nitrophenyl)amino]-3-thiophencarbonitril, Sulfathiazol, Carbamazepin und trans-ZimtsĂ€ure.Chemistry and Chemical Biolog
Early effects of kidney transplantation on the heart - A cardiac magnetic resonance multi-parametric study
Increased native myocardial T1 times in chronic kidney disease (CKD) may be due to diffuse interstitial myocardial fibrosis (DIF) or due to interstitial edema/inflammation. Concerns relating to nephrogenic systemic fibrosis
with gadolinium-based contrast agents (GBCA) limit their use in end-stage kidney disease (ESKD) to measure
extracellular volume (ECV) and characterise myocardial fibrosis. This study aimed to examine stability of
myocardial T1 and T2 times before, and within 2 months after kidney transplantation; a time frame when volume
status normalises but myocardial remodelling is unlikely to have occurred, and to compare these with ECV using
GBCA after transplantation. Twenty-four patients with ESKD underwent serial cardiovascular magnetic
resonance imaging, including T1 and T2 mapping. GBCA was administered on follow-up provided eGFR was
N30 ml/min/1.73 m2
. Eighteen age- and sex-matched controls were studied at one timepoint. ECV (ECV 28 ±
2% vs. 24 ± 2%, p = 0.001) and T2 times were higher in ESKD compared to controls. After transplantation, septal
T1 times increased (MOLLI 985 ms ± 25 vs. 1002 ms ± 30, p = 0.014; ShMOLLI 974 ms ± 39 vs. 992 ms ± 33,
p = 0.113), LV volumes reduced (LVEDvol indexed 79 ± 24 vs. 63 ± 20 ml/m2
, p = 0.005) but LV mass was
unchanged (LV mass index 89 g/m2 ± 38 to 83 g/m2 ± 23, p = 0.141). T2 times did not change after transplantation. Both ECV and myocardial T1 times are elevated in ESKD, supporting the theory that elevated T1 times are
due to DIF, although a contribution from myocardial edema cannot be fully excluded. The lack of any fall in T1 or
T2 times after transplantation suggests that myocardial T1 times are a stable measure of DIF in CKD
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