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A series of Mn2+ -doped zinc germinate ZGO:xMn2+ (x = 0-0.05) nanorods was synthesized successfully using a hydrothermal method. XRD revealed that crystal phases of the ZGO:xMn2+ were rhombohedral and in the R-3 space group. The Williamson-Hall equation was also used to explain the strain, nanocrystalline size, and stacking fault. Green LEDs were successfully fabricated by coating ZGO:Mn2+ nanorods onto UV-LED chips. For high color purity, CIE of the fabricated green LEDs were (0.2404, 0.5428), which made this material a promising candidate for fabrication of UV-based green LEDs.
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In this study, Magnolia citrata Noot and Chalermglin (Magnoliaceae) essential oil (MCEO) was evaluated for insecticidal activity against the yellow fever mosquito Aedes aegypti and attractant activity for the Mediterranean fruit fly Ceratitis capitata. The leaves of Magnolia citrata (Gioi chanh) were collected from northwestern Vietnam, and the water-distilled MCEO was analyzed by gas-chromatography and mass spectrometry (GC-MS). The major constituents of MCEO were identified as linalool 19%, geranial 16%, citronellal 14%, neral 14%, and sabinene 12%. MCEO showed 100% mortality at 1 µg/µL against 1st instar larvae of Ae. aegypti (Orlando strain, ORL), and the oil exhibited 54% (ORL) and 68% (Puerto Rico strain) mortality at 5 µg/mosquito against Ae. aegypti adult females. Initial screens showed that MCEO had weak insecticidal activity compared to the positive control permethrin. In bioassays with sterile male C. capitata, MCEO exhibited moderately strong attraction, comparable to that observed with a positive control, Tetradenia riparia essential oil (TREO). Herein, the insecticidal and attractant activities of MCEO are reported for the first time.
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Cromatografia Gasosa-Espectrometria de Massas/métodos , Inseticidas/farmacologia , Magnolia/química , Aedes/efeitos dos fármacos , Animais , Ceratitis capitata/efeitos dos fármacos , Magnoliaceae/química , Óleos Voláteis/farmacologiaRESUMO
This article reports on the first attempt of a systematic study on the synthesis of carbon dots (C-dots) for the potential applications in labeling and detection of molybdenum ion (Mo6+ ). Carbon dots (C-dots) were synthesized directly via a simple hydrothermal method using lemon juices as carbon precursor with different temperatures to control the luminescence of C-dots. The obtained C-dots had strong green light emission and the ability to use its luminescence properties as probes for Mo6+ detection application, which is based on Mo6+ induced luminescence quenching of C-dots. This analysis system exhibits strong sensitivity and good selectivity for Mo6+ ion, and a detection limit as low as 20 ppm is achieved. These results suggest that the present C-dots have potential application in optoelectronic, labeling and luminescent probing of Mo6+ ions.
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Citrus/química , Corantes Fluorescentes/química , Molibdênio/análise , Pontos Quânticos/química , Carbono/química , Sucos de Frutas e Vegetais , Humanos , Medições Luminescentes/métodos , Microscopia Eletrônica de Transmissão , Molibdênio/sangue , Sensibilidade e Especificidade , Espectrofotometria Infravermelho , Temperatura , Difração de Raios XRESUMO
The present retrospective study aimed to investigate the diagnostic capacity of and design a diagnostic algorithm for dynamic susceptibility contrast-enhanced MRI (DSCE-MRI) and proton magnetic resonance spectroscopy (1H-MRS) in grading low-grade glioma (LGG) and high-grade glioma (HGG). This retrospective study enrolled 57 patients, of which 14 had LGG and 43 had HGG, five had World Health Organization grade 1, nine had grade 2, 20 had grade 3 and 23 had grade 4 glioma. All subjects underwent a standard 3T MRI brain tumor protocol with conventional MRI (cMRI) and advanced techniques, including DSCE-MRI and 1H-MRS. The associations of grade categorization with parameters in tumor and peritumor regions in the DSCE-MRI were examined, including tumor relative cerebral blood volume (TrCBV) and peripheral relative (Pr)CBV, as well as Tr and Pr cerebral blood flow (CBF) and 1H-MRS, including the creatine (Cr) and N-acetyl aspartate (NAA) ratios of choline (Cho), i.e. the TCho/NAA, PCho/NAA, TCho/Cr and PCho/Cr metabolite ratios. The data were compared using the Mann-Whitney U-test, independent samples t-test, Chi-square test, Fisher's exact test and receiver operating characteristic curve analyses. Decision tree analysis established an algorithm based on cutoffs for specified significant parameters. The PrCBF had the highest performance in the preoperative prediction of histological glioma grading, followed by the TrCBV, PrCBF, TrCBV, PCho/NAA, PCho/Cr, TCho/NAA and TCho/Cr. An algorithm based on TrCBV, PrCBF and TCho/Cr had a diagnostic accuracy of 100% for LGG and 90.7% for HGG and a misclassification risk of 7%. The cutoffs (sensitivity and specificity) were 2.48 (86 and 100%) for TrCBV, 1.26 (83.7 and 100%) for PrCBF and 3.18 (69.8 and 78.6%) for TCho/Cr. In conclusion, the diagnostic algorithm using TrCBV, PrCBF and TCho/Cr values, which were obtained from DSCE-MRI and 1H-MRS, increased diagnostic accuracy to 100% for LGGs and 90.7% for HGGs compared to previous studies using conventional MRI. This non-invasive advanced MRI diagnostic algorithm is recommended for clinical application for constructing preoperative strategies and prognosis of patients with glioma.
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High-efficiency energy transfer (ET) from Sm3+ to Eu3+ leads to dominant red emission in Sm3+, Eu3+ co-doped single-phase cubic CeO2 phosphors. In this work, a series of Sm3+ singly and Sm3+/Eu3+ co-doped CeO2 cubic phosphors was successfully synthesized by solution combustion followed by heat treatment at 800 °C in air. The crystal structure, morphology, chemical element composition, and luminescence properties of the obtained phosphors were investigated using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and photoluminescence analysis. Under 360 nm excitation, the Sm3+ singly doped CeO2 phosphor emitted strong yellow-red light at 573 nm (4G5/2-6H5/2) and 615 nm (4G5/2-6H7/2). Meanwhile, the CeO2:Sm3+, Eu3+ phosphors showed the emission characteristic of both Sm3+ and Eu3+, with the highest emission intensity at 631 nm. The emission intensity of Sm3+ decreased with increasing Eu3+ content, suggesting the ET from Sm3+ to Eu3+ in the CeO2:Sm3+, Eu3+ phosphors. The decay kinetics of the 4G5/2-6H5/2 transition of Sm3+ in the CeO2:Sm3+, Eu3+ phosphors were investigated, confirming the high-efficiency ET from Sm3+ to Eu3+ (reached 84%). The critical distance of energy transfer (RC = 13.7 Å) and the Dexter theory analysis confirmed the ET mechanism corresponding to the quadrupole-quadrupole interaction. These results indicate that the high-efficiency ET from Sm3+ to Eu3+ in CeO2:Sm3+, Eu3+ phosphors is an excellent strategy to improve the emission efficiency of Eu3+.
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Pneumatosis intestinalis (PI) and pneumoperitoneum are commonly recognized as severe signs of gastrointestinal diseases that require emergency surgery. However, these symptoms can also be caused by benign conditions. We describe 4 cases of benign PI and pneumoperitoneum that were detected in different clinical situations (accidental discovery in bilan of aortic dissection (case #1), bilateral pulmonary embolism (case #2), overflow diarrhea due to fecal impaction (case #3), and in follow-up postbiliary digestive anastomosis surgery (case #4), which were addressed with exploratory surgery (case #1) or conservative treatment (the remaining cases), with favorable outcomes. Because PI and pneumoperitoneum can be associated with both life-threatening causes and benign conditions, treatment decisions should be based on the correspondence between clinical and paraclinical features, rather than imaging alone.
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This study aims to investigate the prediction of critical buckling load of steel columns using two hybrid Artificial Intelligence (AI) models such as Adaptive Neuro-Fuzzy Inference System optimized by Genetic Algorithm (ANFIS-GA) and Adaptive Neuro-Fuzzy Inference System optimized by Particle Swarm Optimization (ANFIS-PSO). For this purpose, a total number of 57 experimental buckling tests of novel high strength steel Y-section columns were collected from the available literature to generate the dataset for training and validating the two proposed AI models. Quality assessment criteria such as coefficient of determination (R2), Mean Absolute Error (MAE) and Root Mean Squared Error (RMSE) were used to validate and evaluate the performance of the prediction models. Results showed that both ANFIS-GA and ANFIS-PSO had a strong ability in predicting the buckling load of steel columns, but ANFIS-PSO (R2 = 0.929, RMSE = 60.522 and MAE = 44.044) was slightly better than ANFIS-GA (R2 = 0.916, RMSE = 65.371 and MAE = 48.588). The two models were also robust even with the presence of input variability, as investigated via Monte Carlo simulations. This study showed that the hybrid AI techniques could help constructing an efficient numerical tool for buckling analysis.
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A total of 221 isolates of M. tuberculosis were sampled from hospitals and the general population in the northern plain of Vietnam, one of the most populated region of the country. Genotypic composition and diversity were characterized, and we investigated how they are affected by sampling (hospital vs. general population), correcting for potential confounding effects (location, age and gender of the patients). Spoligotyping and 12 MIRU-VNTR typing were used as first line. Then 15 MIRU-VNTR standard set was used, making 21 MIRU-VNTR typing for the clustered isolates. Result showed that 8 lineages and 13 sub-lineages were circulating in the region. The most predominant lineages were Beijing (38.5%) and EAI (38.5%). Others appeared with small proportions H (1.4%), LAM (1.8%), T (8.1%), X (0.9%), MANU (2.3%), and Zero (0.4%). Higher clustering rate was found in the hospital samples (17.9% in urban and 19.2% in rural areas) compared to the population ones (0%). The typical Vietnamese EAI4-VNM sub-lineage of EAI lineage accounted for 67% of EAI strains and was associated with older ages. Beijing genotypes were associated with younger, urban population and were characterized by high clustering rates. These characteristics strongly suggest that Beijing strains are invading the population, replacing the local EAI-VNM4, thus predicting a more serious tuberculosis situation in the future in the absence of more effective control strategies.
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Genótipo , Mycobacterium tuberculosis/genética , Tuberculose/epidemiologia , DNA Bacteriano , Feminino , Variação Genética , Humanos , Masculino , Mycobacterium tuberculosis/isolamento & purificação , Filogenia , Prevalência , População Rural , População Urbana , Vietnã/epidemiologiaRESUMO
BACKGROUND: Although high prevalences of sexually transmitted infections (STIs) have been reported among female sex workers (FSWs) in some countries of Asia, there is little data about this issue in Vietnam. GOAL: The goal of this study was to determine 1) the prevalence of selected STIs and correlates of chlamydia or gonococcal infection, and 2) contraceptive practices, STI-related symptoms, and healthcare-seeking behavior in FSWs in border provinces of Vietnam. METHODS: Nine hundred eleven FSWs in five border provinces of Vietnam (Lai Chau, Quang Tri, Dong Thap, An Giang, and Kien Giang) were enrolled in a cross-sectional study between December 2002 and January 2003. Study subjects were interviewed about selected sociodemographic and behavioral characteristics, history of STIs, and information about cohabiting partners by a standard interview schedule. Serologic samples were collected for syphilis and urine specimens for gonorrhea and chlamydia. Univariate and multivariate logistic regression analysis was used to determine behavioral and other selected risk factors for gonorrhea/chlamydia among FSWs. RESULTS: Overall, the prevalences of syphilis, gonorrhea, chlamydia, and gonorrhea/chlamydia among FSWs in the five border provinces were 10.7%, 10.7%, 11.9%, and 19.9%, respectively. The prevalence of gonorrhea/chlamydia was higher in the northern and central regions (27-33%) than in the southern region (11-24%). The prevalence of syphilis was low in Lai Chau (1%), but higher than 10% in the other four border provinces. Among FSWs with cohabiting partners, income < or =33 US$ per month (odds ratio [OR] = 5.8, P = 0.009), ever having worked outside Vietnam (OR = 78.2, P = 0.007), partner's age <30 years (OR = 11.7, P = 0.001), and partner's complaint of burning or pain during sex (OR = 15.6, P = 0.02) were significantly associated with gonorrhea/chlamydia. Among single FSWs, sex work <6 months (OR = 2.6, P <0.001) and ever douching in the last month (OR = 1.7, P = 0.026) were associated with gonorrhea/chlamydia. For all FSWs, a complaint of lower abdominal pain (OR = 1.6, P = 0.028) and sex work <6 months (OR = 2.3, P = 0.001) were significantly associated with gonorrhea/chlamydia. CONCLUSIONS: There is a high prevalence of gonorrhea/chlamydia among FSWs in these border provinces of Vietnam. Correlates of gonorrhea/chlamydia identified in this study could be incorporated into treatment algorithms for cervicitis in FSWs in Vietnam.