304 research outputs found
Tissue magnetic susceptibility mapping as a marker of tau pathology in Alzheimer's disease.
Alzheimer's disease is connected to a number of other neurodegenerative conditions, known collectively as 'tauopathies', by the presence of aggregated tau protein in the brain. Neuroinflammation and oxidative stress in AD are associated with tau pathology and both the breakdown of axonal sheaths in white matter tracts and excess iron accumulation grey matter brain regions. Despite the identification of myelin and iron concentration as major sources of contrast in quantitative susceptibility maps of the brain, the sensitivity of this technique to tau pathology has yet to be explored. In this study, we perform Quantitative Susceptibility Mapping (QSM) and T2* mapping in the rTg4510, a mouse model of tauopathy, both in vivo and ex vivo. Significant correlations were observed between histological measures of myelin content and both mean regional magnetic susceptibility and T2* values. These results suggest that magnetic susceptibility is sensitive to tissue myelin concentrations across different regions of the brain. Differences in magnetic susceptibility were detected in the corpus callosum, striatum, hippocampus and thalamus of the rTg4510 mice relative to wild type controls. The concentration of neurofibrillary tangles was found to be low to intermediate in these brain regions indicating that QSM may be a useful biomarker for early stage detection of tau pathology in neurodegenerative diseases
Creation of multiple nanodots by single ions
In the challenging search for tools that are able to modify surfaces on the
nanometer scale, heavy ions with energies of several 10 MeV are becoming more
and more attractive. In contrast to slow ions where nuclear stopping is
important and the energy is dissipated into a large volume in the crystal, in
the high energy regime the stopping is due to electronic excitations only.
Because of the extremely local (< 1 nm) energy deposition with densities of up
to 10E19 W/cm^2, nanoscaled hillocks can be created under normal incidence.
Usually, each nanodot is due to the impact of a single ion and the dots are
randomly distributed. We demonstrate that multiple periodically spaced dots
separated by a few 10 nanometers can be created by a single ion if the sample
is irradiated under grazing angles of incidence. By varying this angle the
number of dots can be controlled.Comment: 12 pages, 6 figure
Some new Hermite–Hadamard type inequalities for functions whose nth derivatives are convex
We first create an integral identity for n-times differentiable functions. Relying on this identity, we establish some new Hermite–Hadamard type inequalities for functions whose nth derivatives are convex
RECENT DEVELOPMENTS IN SYNTHETIC METHODS AND PHARMACOLOGICAL ACTIVITIES OF QUINAZOLINONE DERIVATIVES: A REVIEW
This review article offers A brief overview of the most current advancements in synthesis methods and with regard to the pharmacological effects of quinazolinone derivatives. A heterocyclic hybrid quinazolinone having the chemical formula C8H6N2O. It is composed of rings that have been fused together i.e benzene and pyrimidine. The production of quinazolinone derivatives can be accomplished using a variety of methods, such as the Aza-diels-alder reaction, Aza-witting reaction, reaction aided by microwaves, metal-mediated synthesis, palladium-catalyzed reaction, copper-catalyzed reaction, ultrasound-promoted reaction, oxidative cyclization, reagent refluxing, one-pot synthesis, and aqueous media. This review paper included a wide spectrum of pharmacological activities, including a wide range of antibacterial, anti-inflammatory, and analgesic properties of quinazolinone derivatives as well as anti-cancer and anti-oxidant properties were covered in this study.
Peer Review History:
Received 15 October 2024; Reviewed 7 November; Accepted 21 December; Available online 15 January 2025
Academic Editor: Dr. Iman Muhammad Higazy, National Research Center, Egypt, [email protected]
Average Peer review marks at initial stage: 5.5/10
Average Peer review marks at publication stage: 7.0/1
Correlation between Visual Acuity and Optical Coherence Tomography-Measured Retinal Thickness in Diabetic Macular Edema
Background and Objective: Diabetic macular edema (DME) is one of the common complications of diabetes which significantly accounts for preventable visual impairment and blindness. Central macular thickness (CMT) is a feature found in DME patients. This study aims to determine the relationship between optical coherence tomography (OCT)-measured CMT and visual acuity (VA) in patients with DME before and after intravitreal injection of bevacizumab.
Methods: This cross-sectional study was conducted on 100 patients with diabetic macular edema with involvement of both eyes referred to the Ophthalmology Department of Rouhani Hospital in Babol who underwent intravitreal injection of Bevacizumab. VA (measured by Snellen chart), CMT (measured by OCT), clinical and paraclinical factors (including the duration of diabetes, glycosylated hemoglobin (HbA1c), fasting blood sugar (FBS), hypertension, and smoking history data) were evaluated and compared among all patients just before and 45 days after Bevacizumab injection.
Findings: Before the injection of Bevacizumab in 200 eyes, the mean value of VA (letter score) and mean value of CMT (µm) were 36.83±12.73 and 425.48±85.18 µm, respectively (p<0.001, 95% CI=12.5 – 17.5 and 95% CI=-71.5 – -55.5, respectively). 45 days after Bevacizumab injection, the mean value of absolute VA changes was 15.24±10.16, and the mean value of absolute CMT changes was -67.83±43.08 µm (coefficient=-0.18, 95% CI=-0.39 – 0.05).
Conclusion: Although VA was correlated moderately with CMT and the polynomial regression model enhanced the predictive ability, it remains fully obvious that CMT and clinical factors could play an essential role as VA surrogates
Frequency of Cutaneous Manifestations in Diabetic Patients in Endocrinology Clinic of Babol University of Medical Sciences
BACKGROUND AND OBJECTIVE: Diabetes is the most common endocrine disorder in the world. Understanding the cutaneous manifestations associated with diabetes can help in choosing the appropriate treatment approach in these patients. The aim of this study was to evaluate the frequency of cutaneous manifestations in diabetic patients referred to the endocrinology clinic of Babol University of Medical Sciences.
METHODS: The present cross-sectional study was performed on 300 patients with diabetes referred to Rouhani Hospital in Babol in 2019. Age, gender, BMI, type and duration of diabetes, and patients’ diabetes control status (HbA1C) were recorded and patients were thoroughly examined by a dermatologist and divided into two groups of below and above 50 years. In terms of cutaneous manifestations, they were divided into two groups; with cutaneous manifestations and without cutaneous manifestations.
FINDINGS: 293 patients (97.76%) had type 2 diabetes. The mean age of patients was 55±12 years and the mean duration of diabetes was 9.73±1.20 years. In this study, 130 patients (43%) had cutaneous lesions, of which 76 patients (58.5%) were female. Pruritus, acrochordon, cherry angioma, diabetic dermatopathy, fungal skin infections with frequencies of 25.7%, 21%, 14.3%, 6% and 5.7% were the most common skin disorders, respectively. 68 patients (69.4%) had skin manifestations and had diabetes for more than 10 years. There was a significant difference between the two groups of with and without cutaneous manifestations, gender and duration of diabetes (p<0.001). There was no significant difference between the mean age, BMI and HbA1C in the two groups (p=0.07, p=0.09 and p=0.11, respectively).
CONCLUSION: The results of the study showed that pruritus and acrochordon are the most common cutaneous manifestations and long-term diabetes and female gender are the most important risk factors for cutaneous manifestations
WASTE HEAT RECOVERY IN HEAT PUMP SYSTEMS: SOLUTION TO REDUCE GLOBAL WARMING
Energy conversion technologies, where waste heat recovery systems are included, have received significant attention in recent years due to reasons that include depletion of fossil fuel, increasing oil prices, changes in climatic conditions, and global warming. For low temperature applications, there are many sources of thermal waste heat, and several recovery systems and potential useful applications have been proposed by researchers [1-4]. In addition, many types of equipment are used to recover waste thermal energy from different systems at low, medium, and high temperature applications, such as heat exchangers, waste heat recovery boiler, thermo-electric generators, and recuperators. In this paper, the focus is on waste heat recovery from air conditioners, and an efficient application of these energy resources. Integration of solar energy with heat pump technologies and major factors that affect the feasibility of heat recovery systems have been studied and reviewed as well.
KEYWORDS: waste heat recovery; heat pump
Performances and calibrations of new disruptive UVC β-Ga2O3 sensors for new space applications
We present measurement protocols of performances, test and calibrations of new compact solid-state photodetectors based on β-Ga2O3 oxides, and optimized for the UVC. They present reduced dark currents, permitting room temperature operation suppressing need for a cooling system (mass and power savings) and avoiding cold surfaces that traps environmental contamination. Detectors' response peak around 215-220 nm with a bandpass of 30 nm, allowing to observe the UVC wavelength band responsible of ozone creation in the stratosphere (Herzberg continuum, 200-242 nm) and to achieve solar-blindness for wavelengths above 250 nm. Other key assets of β-Ga2O3 detectors are their radiation hard properties (longer lifetime), and possible sensitivity (several hundreds mA/W at -5 V) that allows operation at lower voltages (reduced power), a key asset for Space applications. These detectors, evaluated, tested and calibrated, will be integrated on the INSPIRE-7 nanosatellite to be launched in 2023
Computational simulation of round thermal jets in an ambient cross flow using a large-scale hydrodynamic model
This paper presents the numerical simulation of single, circular, turbulent, thermal jets discharged into an ambient fluid body with a uniform cross flow. The study utilizes a 3D hydrodynamic model to predict the dynamics of the evolving jets, with the model simulations calibrated against benchmark laboratory experimental datasets. Within the numerical-experimental model comparisons, the mean centreline temperature and velocity fields of the evolving jets are investigated in order to understand and predict the jet diffusion characteristics within the flowing ambient fluid body. Direct comparison between the numerical model predictions and laboratory datasets reveals that, with appropriate parameterization of the mixing processes and the selection of an appropriate numerical grid resolution, the large-scale hydrodynamic model can simulate both the near- and farfield thermal jet behaviour with good overall agreement, thus revealing a valid modelling tool used by environmental regulators for assessing the conformity of water quality of marine wastewater discharges
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