Publications by authors named "Abeykoon S"

Background: Converging evidence from clinical neuroimaging and animal models has strongly implicated dysfunction of thalamocortical circuits in the pathophysiology of schizophrenia. Preclinical models of genetic risk for schizophrenia have shown reduced synaptic transmission from auditory thalamus to primary auditory cortex, which may represent a correlate of auditory disturbances such as hallucinations. Human neuroimaging studies, however, have found a generalized increase in resting state functional connectivity (RSFC) between whole thalamus and sensorimotor cortex in people with schizophrenia (PSZ).

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In considering today's energy challenges, the link between the usage of renewable and non-renewable energy sources and economic growth has gained substantial policy attention. This research examines the complex relationship between these three variables to understand how non-renewable energy consumption and renewable energy consumption interact and what that means for economic growth. This study uses the Granger causality approach to explore the relationships between non-renewable energy consumption, renewable energy consumption, and economic development.

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Background: Individuals with substance use disorder show impaired self-awareness of ongoing behavior. This deficit suggests problems with metacognition, which has been operationalized in the cognitive neuroscience literature as the ability to monitor and evaluate the success of one's own cognition and behavior. However, the neural mechanisms of metacognition have not been characterized in a population with drug addiction.

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Functional magnetic resonance imaging (fMRI) of the auditory and visual sensory systems of the human brain is an active area of investigation in the study of human health and disease. The medial geniculate nucleus (MGN) and lateral geniculate nucleus (LGN) are key thalamic nuclei involved in the processing and relay of auditory and visual information, respectively, and are the subject of blood-oxygen-level-dependent (BOLD) fMRI studies of neural activation and functional connectivity in human participants. However, localization of BOLD fMRI signal originating from neural activity in MGN and LGN remains a technical challenge, due in part to the poor definition of boundaries of these thalamic nuclei in standard T1-weighted and T2-weighted magnetic resonance imaging sequences.

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Continuous square wave voltammetry (cSWV) is a technique that enables the continuous collection of current data (at 100 kHz) to maximize the information content obtainable from a single voltammetric sweep. This data collection procedure results in the generation of multiple voltammograms corresponding to different effective square wave frequencies. The application of cSWV brings significant benefits to electrochemical aptamer-based (E-AB) sensors.

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Microscale electrodes offer the advantages of increased mass transport rates, high sensitivity, and rapid measurement capabilities. Fabricating electrochemical aptamer-based (E-AB) sensors on these electrode platforms opens new applications to chemical and biological sensing but has remained challenging due to low signal-to-noise ratios and monolayer instability. In this article, we report the development and characterization of E-AB sensors on a gold microelectrode platform (∼500 nm radius).

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The ability to monitor dynamic changes in neuropeptide Y (NPY) levels in complex environments can have an impact on many fields, including neuroscience and immunology. Here, we describe the development of an electrochemical, aptamer-based (E-AB) sensor for the dynamic (reversible) measurement of physiologically relevant (nanomolar) concentrations of neuropeptide Y. The E-AB sensors are fabricated using a previously described 80 nucleotide aptamer reported to specifically bind NPY with a binding affinity = 0.

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Background: Placenta accreta spectrum can lead to uncontrollable massive hemorrhage in the perinatal period. Currently, the first-line treatment for placenta accreta spectrum recommended worldwide is hysterectomy. However, adverse outcomes after hysterectomy, including surgical complications, such as difficulty in performing the procedure, and sequelae, such as infertility and psychological issues, cannot be ignored.

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Renewable energy holds a remarkable role in clean energy adaptation due to the much lower carbon footprint it releases compared to other fossil fuels. It also has a positive impact by slowing down the rate of climate change. The study has examined the links between renewable and non-renewable energy use, CO2 emissions and economic growth in developed, developing, and LDCs and Economies in Transition between 1990 and 2019 in 152 countries.

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Square wave voltammetry (SWV) is a voltammetric technique for measuring Faradaic current while minimizing contributions from non-Faradaic processes. In square wave voltammetry, the potential waveform applied to a working electrode and the current sampling protocols followed are designed to minimize contributions from non-Faradaic processes (i.e.

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Article Synopsis
  • Patients with schizophrenia tend to smoke a lot and often struggle with traditional treatments, which highlights the need for new therapies.
  • A study tested a new treatment called deep repetitive transcranial magnetic stimulation (dTMS) on 20 patients to see if it could help reduce smoking and improve brain function.
  • Results showed that those receiving active dTMS took longer to light their first cigarette, suggesting some success in stopping smoking, and imaging studies hinted at potential changes in brain activity and symptoms related to psychosis.
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Objectives: To construct gestation specific reference limits for fetal umbilical (UA), middle cerebral artery (MCA) pulsatility indices (PI) and the cerebroplacental ratio (CPR) in singleton pregnancies with normal BMI between 16 and 40 weeks of gestation.

Methods: We ultrasonographically examined 596 fetuses from women with normal nutritional and health status and minimal environmental constraints on fetal growth. Each mother was considered only once for measurement of fetal Doppler indices, at gestations between 16 and 40 weeks in a prospective cross-sectional study.

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Four conventional activated sludge sewage treatment plants (STPs) in Southern India were chosen to investigate the occurrence of major ions and trace metals in dissolved fraction of the wastewater. Samples were collected from inlet and outlet of STPs during the pre-monsoon and monsoon seasons. Except for a few elements (Mn, Mo and Ni), the concentrations of the rest increased at the outlet of STPs, suggesting that there is an addition of these elements during the treatment process.

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Objetives: The aim of this study was to compare fetal biometry of singleton fetuses in pregnant women with normal nutritional and health status in the Ampara district, with a commonly used reference chart.

Methods: A cross sectional study was carried out in the Ampara District. Women with normal nutritional and health status and minimal environmental constraints on fetal growth (n=714) were enrolled during the first trimester and gestational age was confirmed by fetal crown-rump length measurement between 11 weeks + 0 days and 13 weeks + 6 days.

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Objectives: To construct symphysis-pubis fundal height (SFH) charts to estimate fetal size in pregnant women with a normal body mass index (BMI) and to describe the variation of SFH measurements according to BMI.

Methods: cross sectional study was carried out at Ampara and Gampaha Districts in Sri Lanka. Women with normal nutritional and health status, normal BMI and minimal environmental constraints on fetal growth, with ultra sound confirmation of dates by fetal crown-rump length measurements between 11 weeks and 13 weeks + six days,had their SFH measured, using non-elastic tape and standard techniques, between 24 and 41 weeks gestation.

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Objectives: To assess by ultrasound examination the success of insertion of an intrauterine contraceptive device (IUD) immediately after delivery and to determine the optimal distance between the lower end of the IUD and the internal os in predicting successful retention of an IUD.

Methods: This was a prospective study carried out between December 2012 and April 2013. Two ultrasound examinations, transabdominal and transvaginal, were performed prior to hospital discharge following delivery and again at 6 weeks following delivery in women who received a postpartum IUD.

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Background: In the conventional approach to arterial spin labeling in the rodent heart, the relative difference in the apparent T(1) relaxation times corresponding to selective and non-selective inversion is related to perfusion via a two compartment model of tissue. But accurate determination of T(1) in small animal hearts is difficult and prone to errors due to long scan times and high heart rates. In this study we introduce the theoretical frame work for an alternative method (SI-method) based purely on the signal intensity of slice-select and non-select inversion recovery images at a single inversion time at short repetition time.

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Cervical cancer is the second commonest malignancy in Sri Lankan women. The records of 2075 patients treated for cervical cancer from 1989 to 1993 were reviewed. Thirty-eight patients (1.

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A seroepidemiologic study of California (CAL) serogroup viruses (genus bunyavirus, family Bunyaviridae) was carried out on 952 human and 1,834 animal sera collected from different ecological zones of Sri Lanka (latitudes 5-10 degrees N, longitudes 79-82 degrees E). The sera were screened for neutralizing antibody to Lumbo (LUM), snowshoe hare (SSH), and trivittatus (TVT) viruses by plaque neutralization tests on Vero cells. Of 2,786 sera screened, 262 (9.

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