25 research outputs found
A natural limit on the observable periods of anomalous x-ray pulsars and soft gamma-ray repeaters
We investigate the dependence of the evolution of neutron stars with fallback disks on the strength of the magnetic dipole field of the star. Using the same model as employed by Ertan et al. (2009), we obtain model curves for different dipole fields showing that the neutron stars with magnetic dipole fields greater than ∼ 1013 G on the surface of the star are not likely to become anomalous X‐ray pulsars (AXPs) and soft gamma‐ray repeaters (SGRs). Other sources with conventional dipole fields evolve into the AXP phase if their disk can penetrate the light cylinder. The upper limits to the observed periods of AXP and SGRs could be understood if the disk becomes inactive below a low temperature around 100 K. We summarize our present and earlier results indicated by the evolutionary model curves of these sources with an emphasis on the importance of the minimum disk temperature and the X‐ray irradiation in the long‐term evolution of AXPs and SGRs with fallback disks
On fallback disks and magnetars
The discovery of a disk around the anomalous X-ray pulsar 4U 0142+61, has rekindled the interest in fallback disks around magnetars. We briefly review the assumptions of fallback disk models and magnetar models. Earlier data in optical and near IR bands combined with new Spitzer data in the mid-IR range are compatible with a gas disk. Higher multipole fields with magnetar strengths together with a dipole field of 1012-1013 G on the neutron star surface are compatible with the presence of a disk around the neutron star. The possible presence and properties of a fallback disk after the supernova explosion is a likely initial condition to complement the initial rotation period and initial dipole field in determining the evolutionary paths and different types of isolated neutron stars
Serum zonulin levels in type 2 diabetes patients with diabetic kidney disease
Introduction: Recent data have shown that diabetic kidney disease (DKD) is associated with abnormal gut microbiota composition. Zonulin is a physiological tight junction modulator and an intestinal permeability marker. In this study we aimed to investigate serum levels of zonulin and interleukin 6 (IL-6) in patients with type 2 diabetes mellitus (T2DM) and different levels of albuminuria.
Material and methods: Ninety patients with T2DM and 30 healthy controls (HC) aged between 18 and 65 years were enrolled in the study. T2DM patients were divided into three groups as patients with normoalbuminuria (n = 30), microalbuminuria (n = 30), and macroalbuminuria (n = 30). Serum zonulin and IL-6 levels were measured by ELISA method.
Results: There was no significant difference between groups in terms of age, gender, serum ALT, LDL-C, HDL-C, and zonulin levels (p > 0.05). Significant differences between groups were present for the duration of diabetes (p < 0.001), body mass index (p < 0.001), fasting blood glucose (p < 0.001), creatinine (p < 0.001), uric acid (p = 0.037), triglyceride (p = 0.003), total cholesterol (p < 0.001), glycated haemoglobin (p < 0.001), and IL-6 (p < 0.001) levels. IL-6 levels were significantly increased in the microalbuminuria and macroalbuminuria groups compared to the HC group, but no significant difference was determined between the HC and normoalbuminuria group. In patients with diabetic kidney disease, a significant positive correlation was found between zonulin with IL-6 and proteinuria (rho = 0.296, p = 0.008; rho = 0.190, p < 0.047, respectively). The serum IL-6 level was positively correlated with microalbuminuria and proteinuria (rho = 0.451, p < 0.001; rho = 0.425, p < 0.001, respectively).
Conclusions: We suggest that the serum zonulin level is not a promising biomarker to assess the severity of DKD in patients with long-standing T2DM
Diabetes and bacterial co-infection are two independent risk factors for respiratory syncytial virus disease severity
Diabetes mellitus (DM) is common among older adults hospitalized with lower respiratory tract infection, yet information on the impact of DM on disease severity is limited. This study retrospectively analyzed 46 Turkish patients infected with respiratory syncytial virus (RSV), with information on their comorbidities, co-infection status, and symptoms. Patients are grouped into four severity levels from mild to severe, according to lung parenchymal infiltration status and oxygen level. Similar to previously published studies, we found that comorbidities of diabetes, heart failure, hypertension, co-infection of any type, bacterial co-infection, and age are associated with the disease severity. Cough is the most common symptom (89%) followed by fever (26%) and myalgia, dyspnea, and weakness (around 20%). Using a second-order analysis (two-variable regression), we identified two independent risks for disease severity, the first is represented by diabetes, and the second is represented by bacterial co-infection. We observed two patients whose more severe symptoms were not associated with an older age, but associated with a combination of diabetes and bacterial co-infection. To confirm the true causality from the statistical correlation, further studies are needed
Survival Analyses of COVID-19 Patients in a Turkish Cohort: Comparison between Using Time to Death and Time to Release
Survival analyses of COVID-19 data has its own unique features, in particular, the existence of two distinct events: death and release from the hospital within a very short period of time. This multiple-event situation belongs to a type where the occurrence of the first event prevents the second event to happen, and vice versa. We carried out two cause-specific univariate Cox regression survival analyses, one for time-to-death and another for time-to-release. Each survival analysis is further split into one for onset of symptom to event time and another for hospitalization to event time. We have also carried out a case-control (death vs. release) analysis without considering the time to event information. We observed that risk factors can be detected by either case-control or survival analysis, even though the goal of the two is quite different. We also observed that the two survival analyses may not both reveal a factor being a risk factor, but only one of them does. We prefer this two rounds of Cox regressions over mixture cure model which is only focused on time-to-death events which usually are sample size limited. By utilizing time-to-release events may greatly increase the sample size needed for revealing risk factors for COVID-19.
Doi: 10.28991/SciMedJ-2021-03-SI-1
Full Text: PD
A Study On Synthesis, Biological Activities and Molecular Modelling of Some Novel Trisubstituted 1,2,4-Triazole Derivatives
Akdemir, Atilla/0000-0001-8416-0471WOS: 000442985800005In this study, 1-(4-substitued benzyl)-3,5-diphenyl-1H-1,2,4-triazoles (2 a-e) and ethyl(3,5-diphenyl-/H-1,2,4-triazole-1-yl) acetate (3) were synthesized starting from 3,5-diphenyl-/H1,2,4-triazole (1). The ethyl acetate derivative (3) was converted to 2-(3,5-diphenyl-1H-1,2,4-triazole-1-yl)acetohydrazide (4) in ethanolic medium with hydrazine hydrate. The reaction of the acetohydrazide (4) with suitable isothiocyanates generate 2-[(3, 5-diphenyl-1H-1,2,4-triazole-1-yl)acetyl]-4-methyl/phenyh-Ithiosemicarbazide (5a,b). The cyclization of the thiosemicarbazide (5a,b) in the presence of NaOH (2 M) resulted in the formation of 5-[(3,5-diphenyl-1H-1,2,4-triazole-1-yl)methyl]-4methyl/phenyl-2,4-dihidro-3H-1,2,4-triazole-3-thiol (6a,b). Finally, the synthesized 1,2,4-triazole-3-thiols (6a,b) were converted to their 5-substituebenzyl derivatives (7 a-j). All of the synthesized compounds (1-7) were also examined for antioxidant capacities, and antiurease and anti-acetylcholinesterase (anti-AChE) activities. It has been found that antioxidant capacity and anti-urease activity of the compound 7f is very good in biochemically active compounds.Karadeniz Technical University, BAP, TurkeyKaradeniz Teknik University [FBA-2014-89]The authors are thankful for the financial support from Karadeniz Technical University, BAP, Turkey, through Project number FBA-2014-89
Original Article - Intracranial cavernomas: Analysis of 37 cases and literature review
AIMS: Thirty-seven patients with intracranial cavernomas managed in our department are retrospectively analyzed.
MATERIALS AND METHODS: The data of 37 patients with cavernoma who were admitted to our department between 1995 and 2003 were reviewed retrospectively. There were 30 male and 7 female patients with a median age of 26 years (range, 9-57 years). Four cases were treated surgically, 13 were treated by stereotactic radiosurgery (SRS) and the remainder were managed conservatively.
RESULTS: New hemorrhage or additional neurological deficits were not observed in the surgically treated cases, 12 patients who underwent SRS and the other patients who were followed up. One of the 13 patients treated by SRS, underwent microsurgery due to increased seizure frequency. One of the patients treated surgically died on the 11th postoperative day.
CONCLUSION: Clinical observation should be the choice of management for patients without new or progressive neurological deficits, without two or more hemorrhages and in patients where the seizures are controlled with drugs. Surgery is the first choice for the cavernomas located in the non-eloquent locations. Radiosurgery may be an alternative for patients having deep-seated and eloquent area located cavernomas and for patients not willing or suitable for surgery
"Snodgraft" Technique for the Treatment of Primary Distal Hypospadias: Pushing the Envelope
Purpose: "Snodgraft" modification has been proposed to reduce the risk of meatal/neourethral stenosis in distal hypospadias. We applied the Snodgraft technique by using inner preputial graft in primary distal hypospadias repair
A rare dementing disease: Adult neuronal ceroid lipofuscinoses
To emphasize the importance of clinical and ultrastructural findings for diagnosing adult neuronal ceroid lipofuscinosis (ANCL), the authors retrospectively reviewed six patients with biopsyproven ANCL. In all cases, ophthalmologic examinations were normal, and electron microscopic studies demonstrated characteristic granular osmiophilic deposits within the eccrine epithelial cells. The inheritance and mechanism of ANCL remain unknown, and the diagnosis is based on clinical features and ultrastructural examination of the cerebral tissue or extracerebral accumulation of lipopigments. This study suggests that ANCL should be considered as a possible diagnosis in patients with early-onset dementia. © 2012 American Psychiatric Association