Background
The COVID‐19 pandemic caused by SARS‐CoV‐2 remains public health burdens and many unresolved issues worldwide. Molecular assays based on real‐time RT‐PCR are critical for the detection of ...SARS‐CoV‐2 in clinical specimens from patients suspected of COVID‐19.
Objective
We aimed to establish and validate an in‐house real‐time RT‐PCR for the detection of SARS‐CoV‐2.
Methodology
Primers and probes sets in our in‐house real‐time RT‐PCR assay were designed in conserved regions of the N and E target genes. Optimized multiplex real‐time RT‐PCR assay was validated using the first WHO International Standard (NIBSC code: 20/146) and evaluated clinical performance.
Results
The limit of detection validated using the first WHO International Standard was 159 IU/ml for both E and N target genes. The evaluation of clinical performance on 170 clinical samples showed a positive percent agreement of 100% and the negative percent agreement of 99.08% for both target genes. The Kappa value of 0.99 was an excellent agreement, the strong correlation of Ct values observed between two tests with r2 = 0.84 for the E gene and 0.87 for the N gene. Notably, we assessed on 60 paired saliva and nasopharyngeal samples. The overall agreement was 91.66%, and Kappa value of 0.74 showed a high agreement between two types of samples. When using nasopharyngeal swabs as the reference standard, positive percent agreement, and negative percent agreement were 91.83% and 90.90%, respectively.
Conclusion
In the present study, we established and validated an in‐house real‐time RT‐PCR for molecular detection of SARS‐CoV‐2 in a resource‐limited country.
•Dual-mode intense green emission of HA/β-TCP: Er-Yb-Mo composite synthesized by hydrothermal method.•Mo6+ doped system enhances strongly both UC and DC green emissions.•Dual-mode mechanism of ...HA/β-TCP:Er-Yb-Mo phosphor has explained.•Good temperature sensing property was obtained.
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This work presents a novel multifunctional material synthesized by hydroxyapatite/ β-tricalcium phosphate (HA/β-TCP) doped with Er-Yb-Mo ions (using hydrothermal method) and its characterization, showing a peculiar property of green dual-mode emissions (up and down-conversions). It was found that the obtained material exhibits an intense green emission (510–560 nm) both via up-conversion (excited by 975 nm) and down-conversion (excited by 379 nm), which depend on the Mo6+ contents. Particularly, compared with the free-Mo6+ sample, the green emission intensities of the samples doped with 5% Mo6+ mol are 50 and 35 times higher for UC and DC emissions, respectively. Furthermore, the temperature sensing property of the HA/β-TCP: Er-Yb-Mo composite is investigated by fluorescence intensity ratio (FIR) technique, showing a high and competitive sensitivity with a maximum value of 0.0064 K−1 at 403 K. The results indicated that the HA/β-TCP: Er-Yb-Mo phosphor can be useful for high-temperature-sensing applications.
Late detection of hepatocellular carcinoma (HCC) results in an overall 5-year survival rate of less than 16%. Liquid biopsy (LB) assays based on detecting circulating tumor DNA (ctDNA) might provide ...an opportunity to detect HCC early noninvasively. Increasing evidence indicates that ctDNA detection using mutation-based assays is significantly challenged by the abundance of white blood cell-derived mutations, non-tumor tissue-derived somatic mutations in plasma, and the mutational tumor heterogeneity.
Here, we employed concurrent analysis of cancer-related mutations, and their fragment length profiles to differentiate mutations from different sources. To distinguish persons with HCC (PwHCC) from healthy participants, we built a classification model using three fragmentomic features of ctDNA through deep sequencing of thirteen genes associated with HCC.
Our model achieved an area under the curve (AUC) of 0.88, a sensitivity of 89%, and a specificity of 82% in the discovery cohort consisting of 55 PwHCC and 55 healthy participants. In an independent validation cohort of 54 PwHCC and 53 healthy participants, the established model achieved comparable classification performance with an AUC of 0.86 and yielded a sensitivity and specificity of 81%.
Our study provides a rationale for subsequent clinical evaluation of our assay performance in a large-scale prospective study.
In this paper, a novel material based on Er-Yb-Mo tri-doped HA/β-TCP phosphor for intense green up-conversion (UC) emission was successfully synthesized by solid-state reaction method. X-ray ...diffraction (XRD) measurements verified that the materials including a trace amount of HA phase has a hexagonal structure and main β-TCP phase has a rhombohedral structure, which is controlled by the doped ions. Under excitation wavelength of 976 nm laser diode, the HA/β-TCP:Er-Yb-Mo phosphor showed strong green UC emission band at 520/556 nm and weak red emission band at 656 nm which are attributed to (2H11/2, 4S3/2) - 4I15/2, 4F9/2 - 4I15/2 transition of the Er3+ ion, respectively. Remarkably, compared with the sample without Mo6+, the green emission intensities increased ∼650 times was achieved by using Er3+-Yb3+-Mo6+ doped phosphor. The high efficiency of the UC can be attributed to novel energy transfer process from |2F7/2, 3T2> state of Yb3+ - MoO42− dimer to the 4F7/2 of Er3+ ions. Moreover, the grain orientations due to the effect of Mo6+ ions doped in β-TCP phosphor could play an important role in the enhancement of UC emission intensity. These results indicate that the HA/β-TCP: Er-Yb-Mo phosphor has potential application in biological imaging and medicine.
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•Novel upconversion material (Er-Yb-Mo tri-doped HA/β-TCP phosphor) was facilely synthesized by solid-state reaction method.•The crystalline single – phase of β-TCP was achieved by doping with Mo6+ ions.•The green emission intensity of the sample doped with Mo was 650 times higher compared with the sample without Mo.•The selective green upconversion emission can be controlled by controlling the doping Mo6+ concentration in HA/β-TCP: Er3+-Yb3+.
In this study, the nanocomposite of γ-Fe
2
O
3
and reduced-graphene oxide (RGO) with 10% wt RGO was synthesized via the combination of the modified Hummers and co-precipitation methods. The ...structural properties of the γ-GFO powder and tablet were characterized through X-ray diffraction analysis, field-scanning electron microscopy, Brunauer–Emmett–Teller analysis, Raman spectroscopy, and Fourier transform infrared spectroscopy. After undergoing heat treatment at 120 °C, the tablet exhibited a nanoporous structure with an S
BET
of 94.5 m
2
/g, which was slightly higher than the S
BET
of the powder sample. Batch and fixed-bed column studies were conducted to evaluate the performance of γ-GFO in the removal of heavy metals from aqueous solutions. Results showed that the RGO/γ-Fe
2
O
3
(γ-GFO) tablet showed an individual adsorption efficiency of 99.7% for As (V) after 45 min and good simultaneous adsorption capacity for the five heavy metals As, Pb, Cr, Fe, and Mn. These results suggested that γ-GFO is very promising for applications in adsorbing heavy metals in borehole water filters.
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.
In the automatic welding process, the precision of the welding position significantly influences welding quality, relying heavily on the accurate identification of the welding seam. However, in ...complex and unstructured welding environments, such as those with strong arc lights, welding splashes, and thermal-induced deformations, various disturbances present a significant challenge to identify the welding seam. This paper introduces a cost-effective welding seam tracking model constructed using a laser line and a fixed viewpoint single RGB camera. The model's primary objective is to detect a chain of welding-seam points in both captured images and real-time camera feeds. The paper presents the techniques for camera calibration, laser detection, and the use of artificial intelligence to establish a real-world coordinate frame. The process begins with camera calibration using the OpenCV library to filter noise and undistort images. Subsequently, the thresholding technique is employed for color image segmentation, isolating the laser sensor light on the workpiece. An algorithm is then introduced to detect welding spots. Finally, the image coordinates are converted to world coordinates using two machine learning methods: Random Forest Regression and Gradient Boosting Regression. Experimental demonstrations were conducted at different positions on the object to assess algorithm precision. The results indicate average deviations of 0.83 mm, 0.74 mm, and 0.77 mm for X, Y, and Z coordinates, respectively, which fall below the expected standard deviation of 3 mm. Despite the overall consistency of the program, slight noise from environmental lighting may still exist. In conclusion, the proposed welding seam tracking method and coordinate conversion program have proven effective and cost-efficient, with potential for future improvements.
This paper introduces a cost-effective welding seam tracking model constructed using a laser line and a fixed viewpoint single RGB camera. The model's primary objective is to detect a chain of welding-seam points in both captured images and real-time camera feeds.•The welding spots are detected based on the laser sensor light on the workpiece.•The image coordinates are converted to world coordinates using two machine learning methods: Random Forest Regression and Gradient Boosting Regression.•The results indicate average deviations of 0.83 mm, 0.74 mm, and 0.77 mm for X, Y, and Z coordinates, respectively, which fall below the expected standard deviation of 3 mm.
In this study, we described "PT for Sleep Apnea", a smartphone application for home-based physical therapy of patients with Obstructive Sleep Apnea (OSA).
The application was created in a joint ...program between the University of Medicine and Pharmacy at Ho Chi Minh City (UMP), Vietnam, and National Cheng Kung University (NCKU), Taiwan. Exercises maneuvers were derived from the exercise program previously published by the partner group at National Cheng Kung University. They included exercises for upper airway and respiratory muscle training and general endurance training.
The application provides video and in-text tutorials for users to follow at home and a schedule function to assist the user in organizing the training program, which may improve the efficacy of home-based physical therapy in patients with Obstructive Sleep Apnea.
In the future, our group plans to conduct a user study and randomized-controlled trials to investigate whether our application can benefit patients with OSA.
High-efficiency energy transfer (ET) from Sm 3+ to Eu 3+ leads to dominant red emission in Sm 3+ , Eu 3+ co-doped single-phase cubic CeO 2 phosphors. In this work, a series of Sm 3+ singly and Sm 3+ .../Eu 3+ co-doped CeO 2 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 Sm 3+ singly doped CeO 2 phosphor emitted strong yellow-red light at 573 nm ( 4 G 5/2 – 6 H 5/2 ) and 615 nm ( 4 G 5/2 – 6 H 7/2 ). Meanwhile, the CeO 2 :Sm 3+ , Eu 3+ phosphors showed the emission characteristic of both Sm 3+ and Eu 3+ , with the highest emission intensity at 631 nm. The emission intensity of Sm 3+ decreased with increasing Eu 3+ content, suggesting the ET from Sm 3+ to Eu 3+ in the CeO 2 :Sm 3+ , Eu 3+ phosphors. The decay kinetics of the 4 G 5/2 – 6 H 5/2 transition of Sm 3+ in the CeO 2 :Sm 3+ , Eu 3+ phosphors were investigated, confirming the high-efficiency ET from Sm 3+ to Eu 3+ (reached 84%). The critical distance of energy transfer ( R C = 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 Sm 3+ to Eu 3+ in CeO 2 :Sm 3+ , Eu 3+ phosphors is an excellent strategy to improve the emission efficiency of Eu 3+ .
C-doped CeO
2
nanoparticles were synthesized by hydrothermal method using glucose as carbon source. The structure of the C-doped CeO
2
nanoparticles was controlled by the concentration of the glucose ...precursor. The structure and properties of the C-doped CeO
2
nanoparticles were characterized by X-ray diffraction and UV-Vis diffuse reflectance spectroscopy. Microscopic morphology of nanoparticles was characterized by transmission electron microscopy. Photocatalytic activity was assessed by considering the degradation of methylene blue under visible light irradiation. Results show that C-doping significantly improves the photocatalytic activity of CeO
2
nanoparticles because of the combination of extending radiation absorption in visible light and the efficient separation of electron–hole pairs. These findings suggest that the present method is useful for controlling the microstructure and dye degradation properties of C-doped CeO
2
nanoparticles, which is particularly important for catalyst engineering.
