132 research outputs found

    Occurrence, Toxicity and Adsorptive Removal of the Chloramphenicol Antibiotic in Water: A Review

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    Chloramphenicol is a broad-spectrum bacterial antibiotic used against conjunctivitis, meningitis, plague, cholera, and typhoid fever. As a consequence, chloramphenicol ends up polluting the aquatic environment, wastewater treatment plants, and hospital wastewaters, thus disrupting ecosystems and inducing microbial resistance. Here, we review the occurrence, toxicity, and removal of chloramphenicol with emphasis on adsorption techniques. We present the adsorption performance of adsorbents such as biochar, activated carbon, porous carbon, metal-organic framework, composites, zeolites, minerals, molecularly imprinted polymers, and multi-walled carbon nanotubes. The effect of dose, pH, temperature, initial concentration, and contact time is discussed. Adsorption is controlled by π-π interactions, donor-acceptor interactions, hydrogen bonding, and electrostatic interactions. We also discuss isotherms, kinetics, thermodynamic data, selection of eluents, desorption efficiency, and regeneration of adsorbents. Porous carbon-based adsorbents exhibit excellent adsorption capacities of 500-1240 mg

    Comparison study on secrecy probability of AF-NOMA and AF-OMA networks

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    The strictly positive secrecy capacity (SPSC) performance is examined in a new design of non-orthogonal multiple access (NOMA) considered in this study. This system model employs Amplify-and-Forward (AF) relaying scheme to serve far users. In this scheme, a transmitter sends confidential signal to far users. It can be raised falling performance in the presence of an external eavesdropper in such NOMA system. With regard to orthogonal multiple access (OMA), performance of NOMA system model is compared. In particular, tradeoff the SPSC performance and transmit SNR is examined. In this study, the SPSC is evaluated as the secrecy metric to limit impacts of the practical passive eavesdropper in real scenario. It is confirmed that the secrecy performance of NOMA is significant lower than OMA due to related parameters characterization in NOMA, and it should be controlled by varying related coefficients. As main results, both of NOMA and OMA against to impact of eavesdropper is studied in terms of analytically result and numerically result

    A Design of Similar High-gain and Dual-band Frequency/Polarization Reconfigurable Antenna for ISM Band Applications

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    This paper proposes a frequency/polarization reconfigurable antenna (RA) incorporating with Frequency Selective Surface (FSS) to achieve dual-band and similar high-gain characteristics. The proposed RA-FSS design using 4 PIN Diodes can switch between circular polarization (CP) at 1.8 GHz and linear polarization at 2.45 GHz. The fabricated prototype shows good CP performance at 1.8 GHz while the measured peak broadside gains are about 7.2 dBi at 1.8 GHz and 8.5 dBi at 2.45 GHz when PIN diode ON and OFF, respectively

    NOMA-assisted multiple access scheme for IoT deployment: Relay selection model and secrecy performance improvement

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    In this paper, an Internet-of-Things (IoT) system containing a relay selection is studied as employing an emerging multiple access scheme, namely non-orthogonal multiple access (NOMA). This paper proposes a new scheme to consider secure performance, to be called relay selection NOMA (RS-NOMA). In particular, we consider metrics to evaluate secure performance in such an RS-NOMA system where a base station (master node in IoT) sends confidential messages to two main sensors (so-called NOMA users) under the influence of an external eavesdropper. In the proposed IoT scheme, both two NOMA sensors and an illegal sensor are served with different levels of allocated power at the base station. It is noticed that such RS-NOMA operates in two hop transmission of the relaying system. We formulate the closed-form expressions of secure outage probability (SOP) and the strictly positive secure capacity (SPSC) to examine the secrecy performance under controlling setting parameters such as transmit signal-to-noise ratio (SNR), the number of selected relays, channel gains, and threshold rates. The different performance is illustrated as performing comparisons between NOMA and orthogonal multiple access (OMA). Finally, the advantage of NOMA in secure performance over orthogonal multiple access (OMA) is confirmed both analytically and numerically.Web of Science193art. no. 73

    Effects of yeast extract and methyl jasmonate on the enhancement of solasodine biosynthesis in cell cultures of Solanum hainanense Hance

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    In this work, the effects of the elicitors methyl jasmonate (MeJA) and yeast extract (YE) on the growth and solasodine production of Solanum hainanense cells were investigated. The results showed that various concentrations of MeJA (50-250 µM) and YE (1-4 g/L) have different eliciting influences. The increase of solasodine content induced by the elicitation of 3 g/L of YE and 50 µM of MeJA at the beginning of cell culture was about 1.9- and 1.3-fold, respectively, as compared with that of the non-elicitated cells. In general, YE (biotic elicitor) was more effective in enhancing solasodine production than MeJA (abiotic elicitor)

    Prescription of antipsychotics and prevalence of metabolic syndrome in Vietnamese inpatients with schizophrenia

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    Schizophrenia is a severe mental illness, characterized by psychotic symptoms including delusions, hallucinations, dystonia, adolescent behavior and language, and is accompanied by severe functional impairments. Antipsychotics, which are used mainly in the treatment of schizophrenia, have contributed to the development of metabolic syndrome. Studies on metabolic syndrome in schizophrenic patients have been still limited in Vietnam. The objective of this study was to investigate the prevalence of metabolic syndrome in Vietnamese inpatients with schizophrenia. The study population of this descriptive cross-sectional study was all patients with schizophrenia from September 2020 to June 2021 at Inpatient Department of Binh Dinh Provincial Psychiatric Hospital in Viet Nam. Three hundred and twelve patients who met the sampling requirements were enrolled in this study. The prevalence of schizophrenia in female patients was lower than in male patients (36.9% vs. 63.1%) in our study. The prevalence of metabolic syndrome was 30.4% (25.9% in men and 38.3% in women), more in patients ≥40 years old than in patients under 40 years old (the highest prevalence in patients ≥60 years). There was a significant relationship between age, body mass index (BMI), and duration of antipsychotic treatment with the frequency of metabolic syndrome. In conclusions, the prevalence of schizophrenia was higher in male inpatients than in female inpatients. However, the prevalence of metabolic syndrome was higher in female inpatients than male inpatients with schizophrenia, and increased with age, BMI, and duration of antipsychotic treatment

    Tính chất đàn hồi và nhiệt động lực học của nano tinh thể cadmi selenide

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    The elastic and thermodynamic of zincblende CdSe nano crystals have been investigated by first-principles calculations based on density functional theory (DFT). The type of CdSe structure was optimized from the experimental parameter values. The mechanic characterization was determined based on the computed values of independent elastic constants C11, C12, and C44. The temperature dependence of a series of thermodynamic properties functions such as free energy, entropy, enthalpy, and heat capacity are calculated and analyzed in detail.Các tính chất đàn hồi và nhiệt động lực học của nano tinh thể (NC) cadmi selenide (CdSe) có cấu trúc zincblend đã được nghiên cứu trên cơ sở tính toán nguyên tắc ban đầu bằng phương pháp phiếm hàm mật độ (DFT). Thông số cấu trúc tinh thể được tối ưu hóa phù hợp với giá trị từ kết quả thực nghiệm. Các hệ số đặc trưng cho tính chất cơ học được xác định thông qua các giá trị tính toán ba hệ số đàn hồi độc lập C11, C12, C44. Sự phụ thuộc vào nhiệt độ của một số hệ số đặc trưng cho tính chất nhiệt động lực học như năng lượng tự do, entropy, entanpy và nhiệt dung cũng được khảo sát và phân tích một cách chi tiết

    Deficient Mismatch Repair Proteins in Gastric Mixed Neuroendocrine Non-Neuroendocrine Neoplasm: A Rare Case Report

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    Mixed neuroendocrine non-neuroendocrine neoplasm (MiNEN) is a rare type of gastric carcinoma with controversial diagnosis and treatment. Recent data implies that deficiency mismatch repair proteins inducing microsatellite instability are considered one of the potential drivers of this disease. Hence, we report a stomach MiNEN with MMR protein loss. An admitted 60-year-old woman complained of epigastric pain. The pathological analysis of the gastro-endoscopic biopsy specimen revealed gastric adenocarcinoma. The radiological staging was cT3N1M0; therefore, she received D2 distal gastrectomy. Suspecting neuroendocrine component admix with adenocarcinoma part on the resected specimen microscopy, applying biomarkers including AE 1/3, synaptophysin, and chromogranin A to confirm the diagnosis of MiNEN. The neuroendocrine part was classified as neuroendocrine tumor grade 2 with Ki 67 at 16.5%. To further understand the molecular characterization of this disease, we evaluated mismatch protein expression by staining MLH1, MSH2, MSH6, and PMS2 antibodies. Interestingly, both components lost MLH1 and PMS2 proteins. Her radical surgery followed oxaliplatin/capecitabine adjuvant chemotherapy. The patient is still well after eight cycles of chemotherapy. dMMR gastric MiNENs and dMMR gastric cancer share many clinical and genetic characteristics. Further studies are necessary to survey the role of dMMR in the prognosis and treatment of this entity

    In vitro bioactivities of Codonopsis javanica root extract from Kon Tum province, Vietnam

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    Dangshen Codonopsis javanica exhibits invaluable medicinal properties in herbal remedies; however, there has currently not been much specific analysis of the phytochemicals and bioactivities of this plant. The root ethanol extract of C. javanica contains substances such as saponins, phenolic acids, terpenoids, and alkaloids. It displays an antibacterial effect against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus cereus with the IC50 values of 150, 100, 150, and 90 μg/mL, respectively. The antioxidant capacity of the root extract was also observed with an IC50 value of 46.8 ± 6.8 μg/mL. Furthermore, the extract exhibits activity on human cancer cell lines HepG2 (IC50 = 83.6 ± 2.7 μg/mL) and MCF-7 (IC50 = 95.3 ± 2.3 μg/mL). Hence, this study provides the basic data for further research on the bioactivities of natural compounds of Dangshen C. javanica for the first time

    Impact of a community-based participatory research project with underserved communities at risk for hepatitis C virus in Ho Chi Minh City, Vietnam: an evaluation study

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    Background: Participatory approaches have become a widely applied research approach. Despite their popularity, there are many challenges associated with the evaluation of participatory projects. Here we describe an evaluation of a community-based participatory research study of underserved communities in Ho Chi Minh City (HCMC), Vietnam at risk for hepatitis C virus. The goals of our evaluation were to explore the main benefits and challenges of implementing and participating in a participatory study and to describe study impacts. Methods: We conducted two meetings with leaders and members of the participating groups followed by in-depth interviews with 10 participants. We then held a dissemination meeting with over 70 participants, including the representatives of each group, researchers from non-governmental organizations (community-based, national and international), and govenrment officials from the Vietnam Ministry of Health and the Department of Health of HCMC. Results: Results include four categories where we describe first the participatory impacts, followed by the collaborative impacts. Then we describe the benefits and challenges of creating and belonging to one of the groups, from members’ and leaders’ points of view. Finally, we describe the key suggestions that participants provided for future research. Conclusion: In conclusion, the evaluation approach led to both a research reflection on the ‘success’ of the project and enabled participants themselves to reflect on the outcomes and benefits of the study from their point of view
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