607 research outputs found

    Functional Imaging of Stimulus Convergence in Amygdalar Neurons during Pavlovian Fear Conditioning

    Get PDF
    Background: Associative conditioning is a ubiquitous form of learning throughout the animal kingdom and fear conditioning is one of the most widely researched models for studying its neurobiological basis. Fear conditioning is also considered a model system for understanding phobias and anxiety disorders. A fundamental issue in fear conditioning regards the existence and location of neurons in the brain that receive convergent information about the conditioned stimulus (CS) and unconditioned stimulus (US) during the acquisition of conditioned fear memory. Convergent activation of neurons is generally viewed as a key event for fear learning, yet there has been almost no direct evidence of this critical event in the mammalian brain. Methodology/Principal Findings: Here, we used Arc cellular compartmental analysis of temporal gene transcription by fluorescence in situ hybridization (catFISH) to identify neurons activated during single trial contextual fear conditioning in rats. To conform to temporal requirements of catFISH analysis we used a novel delayed contextual fear conditioning protocol which yields significant single- trial fear conditioning with temporal parameters amenable to catFISH analysis. Analysis yielded clear evidence that a population of BLA neurons receives convergent CS and US information at the time of the learning, that this only occurs when the CS-US arrangement is supportive of the learning, and that this process requires N-methyl-D-aspartate receptor activation. In contrast, CS-US convergence was not observed in dorsal hippocampus

    Investigation of the in vitro and in vivo biocompatibility of a three-dimensional printed Thermoplastic Polyurethane/Polylactic Acid blend for the development of Tracheal Scaffolds

    Get PDF
    Tissue-engineered polymeric implants are preferable because they do not cause a significant inflammatory reaction in the surrounding tissue. Three-dimensional (3D) technology can be used to fabricate a customised scaffold, which is critical for implantation. This study aimed to investigate the biocompatibility of a mixture of thermoplastic polyurethane (TPU) and polylactic acid (PLA) and the effects of their extract in cell cultures and in animal models as potential tracheal replacement materials. The morphology of the 3D-printed scaffolds was investigated using scanning electron microscopy (SEM), while the degradability, pH, and effects of the 3D-printed TPU/PLA scaffolds and their extracts were investigated in cell culture studies. In addition, subcutaneous implantation of 3D-printed scaffold was performed to evaluate the biocompatibility of the scaffold in a rat model at different time points. A histopathological examination was performed to investigate the local inflammatory response and angiogenesis. The in vitro results showed that the composite and its extract were not toxic. Similarly, the pH of the extracts did not inhibit cell proliferation and migration. The analysis of biocompatibility of the scaffolds from the in vivo results suggests that porous TPU/PLA scaffolds may facilitate cell adhesion, migration, and proliferation and promote angiogenesis in host cells. The current results suggest that with 3D printing technology, TPU and PLA could be used as materials to construct scaffolds with suitable properties and provide a solution to the challenges of tracheal transplantation

    Keberkesanan bahan pendidikan bercetak untuk pengurusan pemakanan dalam kalangan penjaga pesakit kanser kanak-kanak

    Get PDF
    Malpemakanan dalam kalangan pesakit kanser kanak-kanak adalah perkara yang seringkali terjadi semasa menjalani rawatan kanser dan sekiranya tidak diuruskan dengan baik boleh membawa implikasi negatif. Justeru itu, kajian ini dijalankan untuk membina bahan pendidikan bercetak yang bertajuk “Penjagaan Pemakanan untuk Penjaga Kanser Kanak-Kanak” bagi membantu penjaga kanser kanak-kanak dari segi pengurusan pemakanan. Objektif kajian ini adalah untuk menilai tahap pengetahuan, sikap dan amalan (KAP) penjaga sebelum dan selepas menerima bahan pendidikan bercetak serta menilai penerimaan bahan pendidikan bercetak yang dibina dalam kalangan penjaga. Kajian ini berbentuk kuantitatif (kuasi-eksperimen)nyang melibatkan penjaga pesakit kanser kanak-kanak di Institut Pediatrik Hospital Kuala Lumpur (IPHKL) (n=34) dan Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM) (n=34). IPHKL berfungsi sebagai kumpulan eksperimen yang menerima bahan pendidikan bercetak yang dibina manakala PPUKM sebagai kumpulan kawalan menerima risalah yang diterbit oleh Institut Kanser Negara bertajuk“Terapi diet pesakit kanser-kesan sampingan rawatan dan cara mengatasinya”. Hasil kajian mendapati terdapat peningkatan yang signifikan (p<0.05) bagi tahap KAP penjaga untuk kedua-dua kumpulan dengan peningkatan terbanyak bagi kumpulan eksperimen. Skor KAP bagi kumpulan eksperimen adalah 70 ± 8% dan meningkat secara signifikan kepada 92 ± 10% selepas membaca bahan pendidikan bercetak, menunjukkan peningkatan yang lebih tinggi berbanding kumpulan kawalan di mana skor sebelum adalah 70 ± 11% dan meningkat kepada 77 ± 10%. Bagi penilaian penerimaan, terdapat perbezaan yang signifikan (p<0.05) bagi min skor antara kumpulan eksperimen (48.85 ± 4.931) dan kumpulan kawalan (42.29 ± 6.834) dengan ujian t=4.538. Kesimpulannya, bahan pendidikan bercetak yang dibina dapat diterima dengan baik dan berpotensi untuk meningkatkan pengetahuan mengenai pengurusan pemakanan kanser kanak-kanak semasa rawatan dalam kalangan penjaga dengan berkesan. Ini boleh memperbaiki status pemakanan pesakit kanser kanak-kanak untuk mendapatkan hasil klinikal yang lebih baik

    Effect of heating duration on the synthesis of silicon carbide nanotubes by microwave heating of MWCNTs and silica

    Get PDF
    In this article, the effect of heating duration on the synthesis of silicon carbide nanotubes (SiCNTs) was reported. SiCNTs were synthesized from blend of silicon dioxide (SiO2) and multi-walled carbon nanotubes (MWCNTs) in the ratio of 1:3 by using the microwave heating at 1400°C and maintained at duration of 20, 40 and 60 min, respectively. SiCNTs synthesized at heating duration of 40 and 60 min showed the presence of single phase β-SiC in X-ray diffraction patterns. Meanwhile, field emission scanning electron microscope images showed that SiCNTs were formed and no residual of SiO2 and MWCNTs was observed for SiCNTs formed at heating duration of 40 and 60 min. Transmission electron microscopy images showed the SiCNTs have inter-planar spacing of 0.263 nm and tubular structure of nanotube were retained. The peak corresponded to β-SiC was observed at wavelength of 465 nm from the photoluminescence spectroscopy and associated with energy band gap of 2.67 eV. Absorption bands of Si-C bond were detected at 806.23 cm-1 from the Fourier transform infrared spectra. High purity SiCNTs was obtained at 40 and 60 min as indicated by low weight loss by thermo-gravimetric analysis. 40 min is the most suitable heating duration for the synthesis of single phase β-SiCNTs

    Anaplastic Thyroid Carcinoma: A Therapeutic Dilemma

    Get PDF
    Anaplastic thyroid carcinoma (ATC) is one of the most malignant human neoplasms and has a grave prognosis. This study gives an update on our experience with this unusual neoplasm, with specific focus on the response to various treatment modalities. Forty-seven patients with histologically proven ATCs were enrolled (19 men, 28 women; mean age, 62.8 years). This number represents 1.5% among a total of 3,088 thyroid cancers treated between 1977 and 2002. The mean tumor diameter was 8.8 cm, and 22 patients had distant metastasis. Extrathyroidal extension was seen in 26 (89.7%) of the cases that underwent surgery. Treatment modalities adopted could be classified into 5 groups: Group 1, biopsy only; Group 2, biopsy and chemoradiotherapy; Group 3, debulking only; Goup 4, debulking and chemoradiotherapy; Group 5, complete excision and chemoradiotherapy. Survival was calculated from the time of diagnosis, and comparisons of survival were done by log-rank analysis. The mean survival was 4.3 months (range, 1.0-21 months). The mean survival based on treatment modalities were as follows: Group 1 (n = 10), 2.1 months, Group 2 (n = 8); 3.6 months; Group 3 (n = 7), 3.0 months; Group 4 (n = 14), 3.5 months, Group 5 (n = 8), 9.4 months. There was no significant difference in survival time between the various types of treatment modalities. Even though a small improvement in survival was observed with complete excision and aggressive multimodality therapy, nearly all ATCs remain unresponsive to ongoing treatment modalities and as such, present a therapeutic dilemma. A more effective treatment regimen should be sought in order to improve survival

    Isolation and characterization of Pyricularia oryzae isolated from lowland rice in Sarawak, Malaysian Borneo

    Get PDF
    Aims: Rice blast disease caused by Pyricularia oryzae is one of the major biotic diseases of rice in Sarawak, Malaysian Borneo. This study aims to isolate and characterize rice blast fungus obtained from infected leaf collected from four different divisions in Sarawak, viz, Miri, Serian, Sri Aman, and Kuching. Methodology and results: Twelve succeeded isolates were pre-identified as P. oryzae by morphological characteristics of spores, followed by verification through (internal transcribed spacer) ITS sequencing. The isolates were evaluated for morphological characteristics, growth rate and sporulation rate, which were grown on two types of media, (filtered oatmeal agar) FOMA and (potato dextrose agar) PDA. Morphological characterization showed that the colony surface of the different isolates varied from smooth and fluffy to rough and flattened mycelia; some were with the present of concentric rings, and some with aerial mycelia. The growth rate and sporulation rate of each isolate varied based on types of media used. Most of the isolates grew faster on PDA than on FOMA but produced higher number of spores on FOMA as compared to PDA. Conclusion, significance and impact of study: This preliminary study showed that there were variations observed based on morphological and physiological characterization for the different isolates collected in Sarawak, Malaysian Borneo. This study is the first step towards understanding variation in the population of P. oryzae from Sarawak

    First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

    Get PDF
    Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

    Get PDF
    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Sensitivity of the Advanced LIGO detectors at the beginning of gravitational wave astronomy

    Get PDF
    The Laser Interferometer Gravitational Wave Observatory (LIGO) consists of two widely separated 4 km laser interferometers designed to detect gravitational waves from distant astrophysical sources in the frequency range from 10 Hz to 10 kHz. The first observation run of the Advanced LIGO detectors started in September 2015 and ended in January 2016. A strain sensitivity of better than 10−23/Hz−−−√ was achieved around 100 Hz. Understanding both the fundamental and the technical noise sources was critical for increasing the astrophysical strain sensitivity. The average distance at which coalescing binary black hole systems with individual masses of 30  M⊙ could be detected above a signal-to-noise ratio (SNR) of 8 was 1.3 Gpc, and the range for binary neutron star inspirals was about 75 Mpc. With respect to the initial detectors, the observable volume of the Universe increased by a factor 69 and 43, respectively. These improvements helped Advanced LIGO to detect the gravitational wave signal from the binary black hole coalescence, known as GW150914
    corecore