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Diabetes is a metabolic disease that seriously endangers human health, and monitoring glucose levels is one of the main diagnostic methods for its prevention and treatment. In this paper, we propose a high-performance glucose sensor based on the Sagnac interferometer (SI) utilizing photonic crystal fiber (PCF) with micro-holes. By setting two columns of micro-holes in the center of the PCF, the high birefringence effect is obtained to improve the detection sensitivity. All air holes are assumed to fill with the glucose solution, and the sensing characteristics of the PCF sensor are theoretically studied by the finite element method (FEM). The results show that the sensitivity and resolution of the PCF glucose sensor can reach 4.14 nm/(g/L) and 0.48 mg/dL within the concentration range of 0–120 g/L, respectively. In addition, the effects of the partial-filling methods and PCF structural parameters on the sensing performance are also analyzed to achieve optimal performance. The proposed glucose sensor possesses high sensitivity and simple structure, which exhibits good application prospects in the field of medical monitoring. [ABSTRACT FROM AUTHOR]

Accurate localization of objects of interest in remote sensing images (RSIs) is of great significance for object identification, resource management, decision-making and disaster relief response. However, many difficulties, like complex backgrounds, dense target quantities, large-scale variations, and small-scale objects, which make the detection accuracy unsatisfactory. To improve the detection accuracy, we propose an Adaptive Adjacent Context Negotiation Network (A2CN-Net). Firstly, the composite fast Fourier convolution (CFFC) module is given to reduce the information loss of small objects, which is inserted into the backbone network to obtain spectral global context information. Then, the Global Context Information Enhancement (GCIE) module is given to capture and aggregate global spatial features, which is beneficial for locating objects of different scales. Furthermore, to alleviate the aliasing effect caused by the fusion of adjacent feature layers, a novel Adaptive Adjacent Context Negotiation network (A2CN) is given to adaptive integration of multi-level features, which consists of local and adjacent branches, with the local branch adaptively highlighting feature information and the adjacent branch introducing global information at the adjacent level to enhance feature representation. In the meantime, considering the variability in the focus of feature layers in different dimensions, learnable weights are applied to the local and adjacent branches for adaptive feature fusion. Finally, extensive experiments are performed in several available public datasets, including DIOR and DOTA-v1.0. Experimental studies show that A2CN-Net can significantly boost detection performance, with mAP increasing to 74.2% and 79.2%, respectively. [ABSTRACT FROM AUTHOR]

A highly sensitive and simple structure side-polished micro-structured fiber (MOF) refractive index (RI) sensor based on surface plasmon resonance is proposed and studied by the finite element method. The gold nanofilm used to stimulate plasmons is directly deposited on the inner wall of the open-loop channel of a MOF consisting of an arrangement of six cladding air-holes. The sample analyte is arranged on the outer surface of the optical fiber to improve the utilization rate of the sensor and reduce the tediousness of operation. Meanwhile, in order to increase the leakage intensity of evanescent field, three large air-holes were introduced near the fiber core. Research has shown that the proposed sensor can achieve sensing detection in the range of 1.19–1.37 RI. The maximum sensitivity in the x-polarized direction can reach 12,500 nm/RIU, and its corresponding resolution is 3.64 × 10–5 RIU. Moreover, it has a high linear response of 0.9944 within the RI detection range of 1.19–1.33. Obviously, the proposed sensor has a simple structure, wide RI detection range, and high sensitivity, which can make it widely used in biomedical and analytical chemistry. [ABSTRACT FROM AUTHOR]

Objectives: We investigated the association between dietary flavonoids intake and periodontitis. Materials and methods: This cross-sectional study analyzed data from the US National Health and Nutrition Examination Survey 2009–2010 on 3025 participants aged between 30 and 80 years who had full-mouth periodontal examination and dietary flavonoids intake data. This study used periodontal pocket depth (PPD) and clinical attachment loss (CAL) as periodontitis markers. Data were analyzed using multivariate linear regression. Results: After adjusting confounders, the middle tertile of total dietary flavonoids was associated with decreased mean PPD (0.06 mm, P = 0.016) and mean CAL (0.13 mm, P = 0.001) and the top tertile of total dietary flavonoids was significantly associated with decreases in mean PPD (0.05 mm, P = 0.029) and mean CAL (0.11 mm, P = 0.010). Both the middle and top tertiles of total flavonoids intake were significantly related with decreased mean CAL in females, those flossing 0 days/week, overweight and non-diabetic population but not in males, smokers, those flossing 1–6 days/week and diabetic population. Higher anthocyanidins, flavones and flavonols intake was significantly associated with decreased mean PPD and mean CAL while higher flavanones intake was only significantly associated with decreased mean CAL. Higher anthocyanidins intake was particularly related with greatest decreases in mean CAL (top tertile: 0.22 mm, middle tertile: 0.17 mm, both P < 0.010). However, no significant associations were found between isoflavones and flavan_3_ols intake and mean CAL. Conclusions: Higher dietary flavonoids intake may be beneficial for periodontal health. Clinical relevance: Additional anthocyanidins, flavanones, flavones and flavonols intake was associated with improved periodontal health. [ABSTRACT FROM AUTHOR]

Objective: We investigated the association of severely damaged endodontically infected tooth with carotid artery plaque and abnormal mean carotid intima-media thickness (CIMT) ≥ 1.0 mm. Methods: A retrospective analysis of 1502 control participants and 1552 participants with severely damaged endodontically infected tooth who received routine medical and dental checkup in Health Management Center, Xiangya Hospital was performed. Carotid plaque and CIMT were measured with B-mode tomographic ultrasound. Data were analyzed using logistic and linear regression. Results: Severely damaged endodontically infected tooth group had a significantly higher prevalence of carotid plaque (41.62%) compared to 32.22% of carotid plaque in control group. Participants with severely damaged endodontically infected tooth had a significantly higher prevalence of abnormal CIMT (16.17%) and a significantly increased level of CIMT (0.79 ± 0.16 mm) in comparison to 10.79% of abnormal CIMT and 0.77 ± 0.14 mm CIMT in control participants. Severely damaged endodontically infected tooth was significantly related with formation of carotid plaque [1.37(1.18–1.60), P < 0.001], top quartile length [1.21(1.02–1.44), P = 0.029] and top quartile thickness [1.27(1.08–1.51), P = 0.005] of carotid plaque and abnormal CIMT [1.47(1.18–1.83), P < 0.001]. Severely damaged endodontically infected tooth was significantly associated with both single [1.277(1.056–1.546), P = 0.012] and multiple carotid plaques [1.488(1.214–1.825), P < 0.001] and instable carotid plaques [1.380(1.167–1.632), P < 0.001]. Presence of severely damaged endodontically infected tooth increased 0.588 mm of carotid plaque length (P = 0.001), 0.157 mm of carotid plaque thickness (P < 0.001) and 0.015 mm of CIMT (P = 0.005). Conclusion: Severely damaged endodontically infected tooth was associated with carotid plaque and abnormal CIMT. Clinical relevance: Early treatment of endodontically infected tooth is warranted. [ABSTRACT FROM AUTHOR]

Background: Most studies support parafunctions play an important role in temporomandibular disorders (TMD), whereas the association between tooth wear and TMD remains controversial. Betel nut chewing as a parafunction is popular in South and Southeast Asia. We therefore investigated the association of severely worn dentition resulting from betel nut chewing with TMD. Methods: A cross-sectional analysis of 408 control participants (male: 380, female: 28, 43.62 ± 9.54 years) and 408 participants with betel nut chewing related severely worn dentition (male: 380, female: 28, 43.73 ± 8.93 years) who received dental and TMD checkup according to Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) in Health Management Center, Xiangya Hospital was performed. Betel nut chewing related severely worn dentition meant all the natural teeth had moderate to severe tooth wear [Tooth Wear Index (TWI) ≥ 2)] including ≥ 2 severe wear teeth (TWI ≥ 3) due to betel nut chewing. Multivariable logistic regression analysis was used. Results: After adjusting for age, gender, betel nut chewing related severely worn dentition, oral submucosal fibrosis, number of missing teeth, number of dental quadrants with missing teeth, visible third molar and orthodontic history, variables of age, gender and betel nut chewing related severely worn dentition were significant for overall TMD. Multivariable analysis showed betel nut chewing related severely worn dentition was significantly associated with intra-articular TMD [odds ratio and 95% confidence intervals: 1.689 (1.271–2.244), P = 0.001] in a betel nut chewing dose-dependent manner. Conclusion: Betel nut chewing related severely worn dentition was associated with intra-articular TMD. [ABSTRACT FROM AUTHOR]

Background: Congenitally missing tooth is the most common dental abnormality which leaves spaces in the arch, leads to numerous forms of malocclusion due to the Bolton index discrepancy and is even associated with abnormal craniofacial morphology. Even though the roles of malocclusion and tooth loss in temporomandibular disorders (TMD) development remain controversial, basic researches have found some common molecules are involved in osteoarthritis and dental agenesis. However, the association of congenitally missing teeth with TMD is unknown. We hence investigated the association of congenitally missing teeth with TMD. Methods: A cross-sectional analysis of 586 control participants (male: 287, female: 299, 38.33 ± 11.65 years) and 583 participants with non-third molar congenitally missing teeth (male: 238, female: 345, 39.13 ± 11.67 years) who consecutively received routine dental and TMD checkup according to Diagnostic Criteria for Temporomandibular Disorders Axis I in Health Management Center, Xiangya Hospital was performed. Logistic regression analysis was used to study the association of congenitally missing teeth with TMD. Results: The congenitally missing teeth group included 581 hypodontia and 2 oligodontia participants. The congenitally missing anterior teeth participants, the congenitally missing posterior teeth participants and participants with both congenitally missing anterior and posterior teeth accounted for 88.34%, 8.40% and 3.26% of the congenitally missing teeth group respectively. Congenitally missing teeth group had greater ratios of females and orthodontic history. Participants with congenitally missing teeth had a significantly higher prevalence of overall TMD (67.24%) in comparison to control participants (45.90%). After adjusting age, gender, presence of congenitally missing teeth, number of congenitally missing teeth, number of non-congenitally missing teeth, number of dental quadrants with missing teeth, visible third molar and orthodontic history, the variables of age, gender, presence of congenitally missing teeth and number of dental quadrants with missing teeth were significant for overall TMD. Multivariable logistic regression analysis showed congenitally missing tooth was significantly related with overall TMD [odds ratio (OR):1.689(1.080–2.642), P = 0.022], intra-articular TMD [OR: 1.711(1.103–2.656), P = 0.017] and pain-related TMD [OR: 3.093(1.321–7.239), P = 0.009]. Conclusion: Congenitally missing tooth is a risk factor for TMD. When treating the congenitally missing teeth population, TMJ evaluation and multidisciplinary strategies are necessary. [ABSTRACT FROM AUTHOR]

Background: The doctor/nurse and police officer population have some common typical characteristics of great professional pressure and night shift and past studies indicated oral mucosa lesions were closely associated with psychological factors and health-risking behaviors, however the prevalence of recurrent aphthous stomatitis (RAS) and the two commonly seen oral potentially malignant disorders of oral submucosal fibrosis (OSF) and oral leukoplakia in doctor/nurse and police officer in the Betel quid chewing city of Mainland China is unknown The cross-sectional study was to determine the prevalence differences of RAS, oral leukoplakia and OSF among doctor/nurse, police officer and non-doctor/nurse and non-police officer population aged 20–59 years. Methods: RAS, OSF and oral leukoplakia were examined in doctor/nurse group (male: 659, female: 2439), police officer group (male: 839, female: 262) and non-doctor/nurse and non-police officer group (male: 7576, female: 8129) from 2020-11-01 to 2021-08-31 in Health Management Center, Xiangya Hospital in Changsha city, Hunan province. Results: The prevalence rates of RAS, OSF, oral leukoplakia and oral leukoplakia combined with OSF in male and female non-doctor/nurse and non-police officer group are 8.32‰ and 10.83‰, 58.08‰ and 1.23‰, 11.75‰ and 0.25‰, 7.66‰ and 0.12‰ respectively. Compared with the non-doctor/nurse and non-police officer population, prevalence rates of RAS in male (24.27‰) and female (20.50‰) doctor/nurse population were significantly higher. Prevalence rates of OSF (21.24‰) and oral leukoplakia (3.03‰) in male doctor/nurse population were significantly less but prevalence rates of OSF (93.71‰), oral leukoplakia (20.17‰) and oral leukoplakia combined with OSF (15.42‰) for male police officer were significantly greater in comparison with male non-doctor/nurse and non-police officer group. OSF and oral leukoplakia prevalence rates were obvious lower for the female than the counterpart male group, but there were no significant differences of OSF and oral leukoplakia prevalence rates between the female non-doctor/nurse and non-police officer and female doctor/nurse group. Oral leukoplakia was not found in the female police officers. Conclusions: Doctor/nurse population have higher prevalence of RAS. Male doctors/nurses have lower prevalence of OSF and oral leukoplakia, while male police officers have higher prevalence of OSF, oral leukoplakia and oral leukoplakia combined with OSF. [ABSTRACT FROM AUTHOR]

This paper mainly studies the model design of a thin-film heat-flux sensor (TFHFS), and focuses on the comparison of three dynamic calibration methods. The primary motivation for studying this came from the urgent need for heat-flux dynamic measurements in extreme environments, and the one-sidedness of the dynamic performance evaluation of the corresponding TFHFS. The dynamic theoretical model of the TFHFS was originally established on the principle of a temperature gradient on the basis of a thermal radiation boundary. Then, a novel TFHFS sensor was developed, which can be used at temperatures above 880 °C and has a high sensitivity of 2.0 × 10−5 mV/(W/m2). It can function stably for long durations under a heat-flux density of 3 MW/m2. The steady-state, transient, and frequency calibration of a TFHFS were compared to comprehensively analyze the dynamic characteristics of the TFHFS. The steady-state response time measured by the step excitation method was found to be 0.978 s. The QR decomposition method was applied to the steady-state response experimental model construction, and the fitting degree of a second-order transfer function model obtained was 98.61%. Secondly, the transient response time of the TFHFS was 0.31 ms based on the pulse-excitation method. The transient relationship between the surface temperature and the heat flux, and the pulse-width dependence of the TFHFS transient response time were established. Surprisingly, the response frequency of the TFHFS, about 3000 Hz, was efficiently tested using the frequency response function (FRF), which benefitted from the harmonic characteristics of a periodic square-wave excitation signal. Finally, a comprehensive evaluation of the dynamic performance of the TFHFS was realized. [ABSTRACT FROM AUTHOR]

A sensitivity-amplifying optical fiber sensor using cascaded Sagnac interferometers (CSIs) was designed and experimentally demonstrated for the dual-parameter measurement of strain and temperature. The proposed CSIs sensor consisted of two Sagnac interferometers (SIs) in which two identical PANDA polarization-maintaining fibers (PMFs) for just slightly different lengths were inserted. An envelope with a period of 123.6 nm, which was amplified more than 10 times than the single SI, was observed in the interference spectrum. Experimental results showed that the strain sensitivity increased from 32.91 pm/μϵ for the single SI to 336 pm/μϵ for the CSIs, while the temperature sensitivity increased from −1.38 nm/°C for the single SI to −14.86 nm/°C for the CSIs, correspondingly. We also found that the envelope of the CSIs shifted in opposite directions when the longer or shorter PMF was selected as the sensing arm. Higher sensitivity could be realized by selecting longer PMF as the sensing arm. Our proposed CSIs sensor possesses the merits of simple structure, high sensitivity, low cost, and low hysteresis effect, which make it a competitive candidate for strain and temperature monitoring. [ABSTRACT FROM AUTHOR]

A high sensitivity plasmonic temperature sensor based on a side-polished photonic crystal fiber is proposed in this work. In order to achieve high sensitivity and high stability, the gold layer is coated on the side-polished photonic crystal fiber to support surface plasmon resonance. The mixture of ethanol and chloroform is used as the thermosensitive liquid. The performances of the proposed temperature sensor were investigated by the finite element method (FEM). Simulation results indicate that the sensitivity of the temperature sensor is as high as 7.82 nm/°C. It has good linearity (R 2 = 0.99803), the resolution of 1.1 Ă— 10âˆ'3 °C, and the amplitude sensitivity of 0.1008 °Câˆ'1. In addition, the sizes of the small air hole and polishing depth have little influence on the sensitivity. Therefore, the proposed sensor shows a high structure tolerance. The excellent performance and high structure tolerance of the sensor make it an appropriate choice for temperature measurement. [ABSTRACT FROM AUTHOR]

Medical imaging modalities, such as magnetic resonance imaging (MRI) and computerized tomography (CT), have allowed medical researchers and clinicians to examine the structural and functional features of the human body, thereby assisting the clinical diagnosis. However, due to the highly controlled imaging environment, the imaging process often creates noise, which seriously affects the analysis of the medical images. In this study, a medical imaging enhancement algorithm is presented for ankle joint talar osteochondral injury. The gradient operator is used to transform the image into the gradient domain, and fuzzy entropy is employed to replace the gradient to determine the diffusion coefficient of the gradient field. The differential operator is used to discretize the image, and a partial differential enhancement model is constructed to achieve image detail enhancement. Three objective evaluation indexes, namely, signal-to-noise ratio (SNR), information entropy (IE), and edge protection index (EPI), were employed to evaluate the image enhancement capability of the proposed algorithm. Experimental results show that the algorithm can better suppress noise while enhancing image details. Compared with the original image, the histogram of the transformed image is more uniform and flat and the gray level is clearer. [ABSTRACT FROM AUTHOR]

A dual-polarized photonic crystal fiber (PCF) sensor based on surface plasmon resonance (SPR) was proposed for measuring the refractive indexes (RIs) of liquids. A gold film and a liquid analyte were successively wrapped around the outer surface of the PCF to stimulate the external SPR effect, which greatly reduced the manufacturing difficulties, compared to depositing the gold film and filling the inner air holes of the PCF with liquid analyte. The performance of the proposed PCF sensor was numerically investigated using the finite-element method. The results show that the proposed PCF sensor can realize dual-polarized detection in the RI range of 1.36–1.42. The x and y polarization (X-P and Y-P) core modes were coupled to the X-P second-order and Y-P first-order surface-plasmon polariton modes, respectively. As the the RI of the analyte increased, the wavelength sensitivity increased and, as a result, maximum values of 15 900 nm RIU−1 for X-P and 16 900 nm RIU−1 for Y-P were achieved. Correspondingly, we obtained a maximum amplitude sensitivity of 2026.05 RIU−1 for X-P and 2102.65 RIU−1 for Y-P. In addition, the fabrication tolerance of the proposed PCF was increased to ±0.4 μm, which made the proposed PCF a favorable candidate for the detection of liquids. [ABSTRACT FROM AUTHOR]

A fiber/Ag-Cu films surface plasmon resonance (SPR) refractive index (RI) sensor composed of multimode fiber-no-core-fiber-multimode fiber (MMF-NCF-MMF) structure is designed. The sensing region length and Cu film deposition time of sensor are gradually optimized by the control variable method, which finally achieves the improvement of sensor properties. We experimentally compared the sensing performance of the fiber/Ag film and fiber/Ag-Cu films sensor. Experimental results show that the fiber/Ag-Cu films sensor has good linearity (R-square = 0.993), and its sensitivity is as high as 3957 nm/RIU in the refractive index detection range of 1.3328–1.3853, which is 1109 nm/RIU higher than the sensitivity of a conventional fiber/Ag film sensor. The sensor presented in this paper adopts the structure with composite metal film, which outperforms the common single-layer metal film in chemical stability such as oxidation resistance and mechanical hardness. Meanwhile, the SPR sensor with MMF-NCF-MMF structure has the advantages of convenient manufacture and compact structure. In conclusion, it can bestow a unique advantage in the field of biological detection or chemical analysis. [ABSTRACT FROM AUTHOR]

Structure-based forest management is a scientific and easy-to-operate method for sustainable forest management. We analyzed the stand spatial structure of Larix principis-rupprechtii plantation under five reserve densities. The results indicated that with the decrease of densities after thinning, the average mingling degree and uniform angle index had an increasing tendency, but the amplitude was small. Most of the trees were in zero mix, and a few of them were in moderate, strong, and relatively strong mix; the horizontal distribution patterns were uniform or near-uniform random. The distribution of neighborhood comparison and opening degree changed with a fluctuant pattern, but thinning decreased the competitive intensities to some extent. A composite structure index (Ci) was established, based on the relative importance of the above four indicators, to evaluate the overall effect of thinning on stand structure characteristics. The findings showed that Ci increased with the increase of thinning intensity, that is, the stand spatial structure became more complex. This indicated that Ci may be a simple and rapid indicator to evaluate the overall effect of thinning on stand spatial structure within densities after thinning. [ABSTRACT FROM AUTHOR]