159 research outputs found

    Evaluation of Hyperhomocysteinemia in the Progression of Parkinson\u27s Disease

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    Abstract: Objective: To assess the prevalence of hyperhomocysteinemia in Parkinson’s Disease (PD) and if this elevated serum level can be used as a predictive biomarker in risk assessment for the progression of cognitive decline in PD. Design: Systematic Literature Review Methods: A literature search was conducted through Google Scholar and Pubmed using phrases such as, “Parkinson\u27s Disease”, and “homocysteine”, “Parkinson’s progression. Three articles, measuring serum homocysteine levels and cognitive functioning in PD patients, were selected, analyzed, and compared to assess for a relationship between homocysteine levels and cognitive decline in PD. Results: Elevated homocysteine levels are associated with worse cognitive scores in some areas of neurocognitive testing in PD patients as compared to those with normal homocysteine levels. Conclusion: Though study results do show an inversely proportional relationship between homocysteine serum levels and cognitive function, the presence of confounding variables within PD subjects, as well as, the unknown physiologic mechanism of homocysteine and neurons, makes it difficult to find a causal relationship between elevated homocysteine and neurocognitive function in PD

    Cosmological singularities in non-canonical models of dark energy

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    The pursuit of unraveling the true essence of dark energy has become an immensely captivating endeavor in modern cosmology. Alongside the conventional cosmological constant approach, a diverse range of ideas has been proposed, encompassing scalar field-based models and various modified gravity approaches. A particularly intriguing notion involves exploring scalar field dark energy models within quantum gravitationally motivated cosmologies, with non-canonical theories standing out as a prominent candidate in this context. Hence, in this work, we investigate three widely recognized non-canonical scalar field dark energy models: phantom, quintom, and DBI dark energy models. By employing the Goriely-Hyde procedure, we demonstrate the presence of singularities in both finite and infinite time within these frameworks. and that these singularities can manifest regardless of the system's initial conditions. Moreover, we further establish how cosmological singularities of types I-IV can arise in all of these models. The work goes to show that non-canonical regimes for dark energy can allow for most of the prominent cosmological singularities for a variety of models.Comment: v2, matches the accepted version in PDU, 28 pages with no figure

    Decoupling of a Neutron Interferometer from Temperature Gradients

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    Neutron interferometry enables precision measurements that are typically operated within elaborate, multi-layered facilities which provide substantial shielding from environmental noise. These facilities are necessary to maintain the coherence requirements in a perfect crystal neutron interferometer which is extremely sensitive to local environmental conditions such as temperature gradients across the interferometer, external vibrations, and acoustic waves. The ease of operation and breadth of applications of perfect crystal neutron interferometry would greatly benefit from a mode of operation which relaxes these stringent isolation requirements. Here, the INDEX Collaboration and National Institute of Standards and Technology demonstrates the functionality of a neutron interferometer in vacuum and characterize the use of a compact vacuum chamber enclosure as a means to isolate the interferometer from spatial temperature gradients and time-dependent temperature fluctuations. The vacuum chamber is found to have no depreciable effect on the performance of the interferometer (contrast) while improving system stability, thereby showing that it is feasible to replace large temperature isolation and control systems with a compact vacuum enclosure for perfect crystal neutron interferometry

    Insecticide susceptibility in larval populations of the West Nile vector Culex pipiens L. (Diptera: Culicidae) in Saudi Arabia

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    Objective: To investigate the susceptibility to some conventional and non-conventional insecticides in laboratory and field larval populations of the West Nile vector Culex pipiens L. (Cx. pipiens), the dominant species in Jeddah Province, Saudi Arabia. Methods: The tested conventional insecticides were Actikil and Pesgard, while the non-conventional ones were Bacilod, Dudim and Baycidal. Probit analysis and photomicroscopical observations were carried out to shed light on acute toxicity in laboratory and field Cx. pipiens strains. Results: Cx. pipiens were more susceptible to Pesgard (LC50: 0.045 and 0.032 mg/L) than Actikil (0.052 and 0.038 mg/L) and Bacilod (0.129 and 0.104 mg/L), for the field and laboratory strains, respectively. Results showed that treatments with the chitin synthesis inhibitor Dudim and Baycidal evoked morphological effects similar to those induced by other insect growth regulators. According to IC50 values obtained (concentration which to inhibit the emergence of 50% of mosquito adults), the compound Dudim (0.0003 and 0.0001 mg/L) was more effective against Cx. pipiens L. mosquitoes than Baycidal (0.0004 and 0.0003 mg/L) for both the field and laboratory strains, respectively. Conclusions: Our results provide baseline data to enhance control programs and orient public health decisions on the selection of pesticides against mosquito vectors in Saudi Arabia

    Evaluation of behavioural and antioxidant activity of Cytisus scoparius Link in rats exposed to chronic unpredictable mild stress

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    <p>Abstract</p> <p>Background</p> <p>Various human diseases have oxidative stress as one of their component. Many herbs have been reported to exhibit properties that combat oxidative stress through their active constituents such as flavonoids, tannins, phenolic compounds etc. <it>Cytisus scoparius </it>(CS) Link, (Family: Leguminosae), also called <it>Sarothamnus scoparius</it>, has been shown in <it>invitro </it>experiments to be endowed with anti-diabetic, hypnotic and sedative and antioxidant activity. Therefore this study was carried out to evaluate CS for its anxiolytic, antidepressant and anti-oxidant activity in stressed rats.</p> <p>Methods</p> <p>60% methanolic extract of CS was quantified for phenolic content by Folin-Ciocalteau's method. Chronic unpredictable mild stress (CMS) was employed to induce stress in rats. CS (125 and 250 mg/kg, p.o) and diazepam (DZM) (2 mg/kg, p.o) was administered during the 21 day stress exposure period. Anxiolytic and antidepressant activities of CS were assessed in open field exploratory and behavioural despair paradigms, respectively. Plasma glucose and total lipids; endogenous antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT); non-enzymic-ascorbic acid and thiobarbituric acid reactive substances (TBARS) levels were measured in brain, kidneys and adrenals using standard protocols to assess the effect of CS.</p> <p>Results</p> <p>Total phenolic content of CS was found to be 8.54 ± 0.16% w/w. CMS produced anxiogenic and depressive behaviour in experimental rats with metabolic disturbance. Significant decrease in SOD, CAT levels and increase in lipid peroxidation level was observed in stressed rats. CS administration for 21 days during stress exposure significantly increased the ambulatory behaviour and decreased the freezing time in open field behaviour. In behavioural despair test no significant alteration in the immobility period was observed. CS also improved SOD, CAT, and ascorbic acid level and controlled the lipid peroxidation in different tissues.</p> <p>Conclusion</p> <p>CS possesses anti-stress and moderate anxiolytic activity which may be due, in part, to its antioxidant effect that might warrant further studies.</p

    The Magnitude and Mechanism of Charge Enhancement of CH∙∙O H-bonds

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    Quantum calculations find that neutral methylamines and thioethers form complexes, with N-methylacetamide (NMA) as proton acceptor, with binding energies of 2–5 kcal/mol. This interaction is magnified by a factor of 4–9, bringing the binding energy up to as much as 20 kcal/mol, when a CH3+ group is added to the proton donor. Complexes prefer trifurcated arrangements, wherein three separate methyl groups donate a proton to the O acceptor. Binding energies lessen when the systems are immersed in solvents of increasing polarity, but the ionic complexes retain their favored status even in water. The binding energy is reduced when the methyl groups are replaced by longer alkyl chains. The proton acceptor prefers to associate with those CH groups that are as close as possible to the S/N center of the formal positive charge. A single linear CH··O hydrogen bond (H-bond) is less favorable than is trifurcation with three separate methyl groups. A trifurcated arrangement with three H atoms of the same methyl group is even less favorable. Various means of analysis, including NBO, SAPT, NMR, and electron density shifts, all identify the +CH··O interaction as a true H-bond

    30-Day morbidity and mortality of bariatric metabolic surgery in adolescence during the COVID-19 pandemic – The GENEVA study

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    Background: Metabolic and bariatric surgery (MBS) is an effective treatment for adolescents with severe obesity. Objectives: This study examined the safety of MBS in adolescents during the coronavirus disease 2019 (COVID-19) pandemic. Methods: This was a global, multicentre and observational cohort study of MBS performed between May 01, 2020, and October 10,2020, in 68 centres from 24 countries. Data collection included in-hospital and 30-day COVID-19 and surgery-specific morbidity/mortality. Results: One hundred and seventy adolescent patients (mean age: 17.75 ± 1.30 years), mostly females (n = 122, 71.8%), underwent MBS during the study period. The mean pre-operative weight and body mass index were 122.16 ± 15.92 kg and 43.7 ± 7.11 kg/m2, respectively. Although majority of patients had pre-operative testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (n = 146; 85.9%), only 42.4% (n = 72) of the patients were asked to self-isolate pre-operatively. Two patients developed symptomatic SARS-CoV-2 infection post-operatively (1.2%). The overall complication rate was 5.3% (n = 9). There was no mortality in this cohort. Conclusions: MBS in adolescents with obesity is safe during the COVID-19 pandemic when performed within the context of local precautionary procedures (such as pre-operative testing). The 30-day morbidity rates were similar to those reported pre-pandemic. These data will help facilitate the safe re-introduction of MBS services for this group of patients

    30-day morbidity and mortality of sleeve gastrectomy, Roux-en-Y gastric bypass and one anastomosis gastric bypass: a propensity score-matched analysis of the GENEVA data

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    Background: There is a paucity of data comparing 30-day morbidity and mortality of sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and one anastomosis gastric bypass (OAGB). This study aimed to compare the 30-day safety of SG, RYGB, and OAGB in propensity score-matched cohorts. Materials and methods: This analysis utilised data collected from the GENEVA study which was a multicentre observational cohort study of bariatric and metabolic surgery (BMS) in 185 centres across 42 countries between 01/05/2022 and 31/10/2020 during the Coronavirus Disease-2019 (COVID-19) pandemic. 30-day complications were categorised according to the Clavien–Dindo classification. Patients receiving SG, RYGB, or OAGB were propensity-matched according to baseline characteristics and 30-day complications were compared between groups. Results: In total, 6770 patients (SG 3983; OAGB 702; RYGB 2085) were included in this analysis. Prior to matching, RYGB was associated with highest 30-day complication rate (SG 5.8%; OAGB 7.5%; RYGB 8.0% (p = 0.006)). On multivariate regression modelling, Insulin-dependent type 2 diabetes mellitus and hypercholesterolaemia were associated with increased 30-day complications. Being a non-smoker was associated with reduced complication rates. When compared to SG as a reference category, RYGB, but not OAGB, was associated with an increased rate of 30-day complications. A total of 702 pairs of SG and OAGB were propensity score-matched. The complication rate in the SG group was 7.3% (n = 51) as compared to 7.5% (n = 53) in the OAGB group (p = 0.68). Similarly, 2085 pairs of SG and RYGB were propensity score-matched. The complication rate in the SG group was 6.1% (n = 127) as compared to 7.9% (n = 166) in the RYGB group (p = 0.09). And, 702 pairs of OAGB and RYGB were matched. The complication rate in both groups was the same at 7.5 % (n = 53; p = 0.07). Conclusions: This global study found no significant difference in the 30-day morbidity and mortality of SG, RYGB, and OAGB in propensity score-matched cohorts
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