Biochar promotes microbial CO2 fixation by regulating feedback inhibition of metabolites.

Chemoautotrophs, the crucial contributors to biological carbon fixation, derive energy from reducing specific inorganic substances and utilize CO2 for growth. However, the release of extracellular free organic carbon (EFOC) by chemoautotrophic microorganisms can inhibit their own growth and metabolism. To reduce the feedback inhibition effect, a low-release biochar (BC-LR) was applied to adsorb EFOC. BC-LR not only adsorbed EFOC, but also selectively adsorbed the main inhibitory component, low molecular weight organics, in EFOC. In contrast, ordinary biochar could not effectively adsorb EFOC and its addition inhibited microbial growth and CO2 fixation. In Transwell culture, BC-LR promoted microbial growth by 190% and CO2 fixation by 29%, and exhibited better economic advantage, when compared with granular activated carbon. These findings provide a novel insight into the interaction between biochar and autotrophic microbial metabolism, offering an economically feasible approach to mitigate feedback inhibition of metabolites and promoting biological CO2 fixation.

The relationship of dietary flavonoids and periodontitis in US population: a cross-sectional NHANES analysis.

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.

The association of severely worn dentition resulting from betel nut chewing with temporomandibular disorders: a cross-sectional study.

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.

Association of severely damaged endodontically infected tooth with carotid plaque and abnormal carotid intima-media thickness: a retrospective analysis.

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.

Association of congenitally missing teeth with adult temporomandibular disorders in the urban health checkup population.

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.

Prevalence of recurrent aphthous stomatitis, oral submucosal fibrosis and oral leukoplakia in doctor/nurse and police officer population.

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.

Dynamic Calibration of a Thin-Film Heat-Flux Sensor in Time and Frequency Domains.

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.

Lightweight and efficient neural network with SPSA attention for wheat ear detection.

Advancements in deep neural networks have made remarkable leap-forwards in crop detection. However, the detection of wheat ears is an important yet challenging task due to the complex background, dense targets, and overlaps between wheat ears. Currently, many detectors have made significant progress in improving detection accuracy. However, some of them are not able to make a good balance between computational cost and precision to meet the needs of deployment in real world. To address these issues, a lightweight and efficient wheat ear detector with Shuffle Polarized Self-Attention (SPSA) is proposed in this paper. Specifically, we first utilize a lightweight backbone network with asymmetric convolution for effective feature extraction. Next, SPSA attention is given to adaptively select focused positions and produce a more discriminative representation of the features. This strategy introduces polarized self-attention to spatial dimension and channel dimension and adopts Shuffle Units to combine those two types of attention mechanisms effectively. Finally, the TanhExp activation function is adopted to accelerate the inference speed and reduce the training time, and CIOU loss is used as the border regression loss function to enhance the detection ability of occlusion and overlaps between targets. Experimental results on the Global Wheat Head Detection dataset show that our method achieves superior detection performance compared with other state-of-the-art approaches.

Design of Medical Image Detail Enhancement Algorithm for Ankle Joint Talar Osteochondral Injury.

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.

A High-Sensitivity SPR Refractive Index Sensor Based on No-Core Fiber with Ag-Cu Composite Films.

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.

High-sensitivity plasmonic temperature sensor based on gold-coated D-shaped photonic crystal fiber.

A high-sensitivity temperature sensor based on gold-coated D-shaped photonic crystal fiber is proposed in this paper. To enhance the sensing performances, gold as the surface plasmon resonance material is coated on the polishing surface. The thermosensitive liquid consists of ethanol and chloroform, and it is placed on the outer layer of the photonic crystal fiber. As the phase-matching condition is satisfied, the core mode couples to the surface plasmon polariton mode, and energy transfer occurs. The influences of the structural parameters on the sensing characteristics were studied using the finite element method. The numerical results show the average sensitivity can reach up to 10.61 nm/°C, and the linearity R2=0.99341 for the temperature sensing ranges of 0-60°C. Moreover, a good spectral shape can be realized by the proposed fiber. Compared with some previously reported temperature sensors, the proposed temperature sensor shows excellent performances in terms of the sensitivity, detection range, and fabrication.

Broadband single-polarization filter of D-shaped photonic crystal fiber with a micro-opening based on surface plasmon resonance.

In this paper, a D-shaped photonic crystal fiber is designed to achieve a single-polarization filter that has a broadband filtering property. The D-shaped structure is a triangular array of air holes, forming a micro-opening on the side-polished surface and plating a gold layer thereon. The investigation of the polarization filter is based on the finite element method; its principle is surface plasmon resonance. The single-polarization filter in the y direction is realized by adjusting parameters such as the apertures of the fiber, the thickness of the gold layer, and the polishing depth. The confinement loss of the core mode in y polarization reaches to a high value of 376.31 dB/cm at 1.55 µm, and that of the x polarization is 0.17 dB/cm; the former is 2225.35 times the latter. When the fiber length L is 1 mm, the crosstalk reaches a peak value of 326.7 dB at 1.55 µm, and the bandwidth of crosstalk higher than 20 dB is 480 nm. In addition, the external gold coating operation is more conducive to application in the manufacturing process. This filter will be an effective application of the optical communication window near 1.55 µm.

Ultrahigh sensitivity refractive index sensor of a D-shaped PCF based on surface plasmon resonance.

We propose a D-shaped photonic crystal fiber (PCF) refractive index sensor with ultrahigh sensitivity and a wide detection range. The gold layer is deposited on the polished surface, avoiding filling or coating inside the air holes of the PCF. The influences of the gold layer thickness and the diameter of the larger air holes are investigated. The sensing characteristics of the proposed sensor are analyzed by the finite element method. The maximum sensitivity can reach 31,000 nm/RIU, and the refractive index detection range is from 1.32 to 1.40. Our proposed PCF has excellent sensing characteristics and is competitive in sensing devices.

ß2-Adrenergic signal transduction plays a detrimental role in subchondral bone loss of temporomandibular joint in osteoarthritis.

The present study tested whether activation of the sympathetic tone by aberrant joint loading elicits abnormal subchondral bone remodeling in temporomandibular joint (TMJ) osteoarthritis. Abnormal dental occlusion was created in experimental rats, which were then intraperitoneally injected by saline, propranolol or isoproterenol. The norepinephrine contents, distribution of sympathetic nerve fibers, expression of ß-adrenergic receptors (ß-ARs) and remodeling parameters in the condylar subchondral bone were investigated. Mesenchymal stem cells (MSCs) from condylar subchondral bones were harvested for comparison of their ß-ARs, pro-osteoclastic gene expressions and pro-osteoclastic function. Increases in norepinephrine level, sympathetic nerve fiber distribution and ß2-AR expression were observed in the condylar subchondral bone of experimental rats, together with subchondral bone loss and increased osteoclast activity. ß-antagonist (propranolol) suppressed subchondral bone loss and osteoclast hyperfunction while ß-agonist (isoproterenol) exacerbated those responses. MSCs from experimental condylar subchondral bone expressed higher levels of ß2-AR and RANKL; norepinephrine stimulation further increased their RANKL expression and pro-osteoclastic function. These effects were blocked by inhibition of ß2-AR or the PKA pathway. RANKL expression by MSCs decreased after propranolol administration and increased after isoproterenol administration. It is concluded that ß2-AR signal-mediated subchondral bone loss in TMJ osteoarthritisis associated with increased RANKL secretion by MSCs.

[The significance of serum N-terminal pro-brain natriuretic peptide levels for prognosis of patients in intensive care unit].

OBJECTIVE: To assess the significance of elevated serum N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in predicting 30-day mortality rate for patients in intensive care unit (ICU). METHODS: A retrospective study was conducted. The clinical data of 480 patients admitted to ICU in Tianjin First Center Hospital from June 2012 to October 2013 were studied. The characteristics of patients were recorded, the acute physiology and chronic health evaluationII ( APACHEII) score was calculated, and the routine blood tests, blood biochemistry, and serum NT-proBNP level within 24 hours after admission were determined. Patients were divided into non-survival and survival groups according to 30-day outcome, and the characteristics and clinical parameters were compared between two groups, and single factor analysis affecting prognosis was analyzed. All patients were divided into four groups according to four percentile method as NT-proBNP<280 ng/L (group Q1), 280 ng/L≤NT-proBNP<1 200 ng/L (group Q2), 1 200 ng/L≤NT-proBNP<1 990 ng/L (group Q3), 1 990 ng/L≤NT-proBNP<4 700 ng/L (group Q4). A Cox regression analysis was used to test the independence of the predictors. A receiver operator characteristic curve (ROC curve) was plotted to compare the power of APACHEII score and NT-proBNP in predicting the outcome. Kaplan-Meier analysis was used to assess survival rate among different NT-proBNP patients. RESULTS: By single factor analysis it was shown that age, APACHEII score, creatinine, NT-proBNP and severe infection were those influencing the outcome. NT-proBNP 1 200-4 700 ng/L (groups Q3 and Q4) and APACHEII score>20 were independent risk factors for predicting outcome [relative risk (RR) for group Q3 was 3.624, 95% credibility interval (95%CI) was 1.258-10.138; RR for group Q4 was 5.059, 95%CI was 3.202-9.993; RR for APACHEII score>20 was 2.987, 95%CI was 1.345-5.823]. The area under the ROC curve (AUC) for APACHEII score and serum NT-proBNP was similar, and it was 0.831 (95%CI 0.778-0.884) and 0.876 (95%CI 0.827-0.925), respectively. The cut-off value of NT-proBNP for predicting mortality was 1 250 ng/L. Kaplan-Meier analysis showed that groups of Q2, Q3 and Q4 had lower cumulative survival rate compared with group Q1 (26.5%, 25.4%, 16.2% vs. 29.6%), and group Q4 showed most significant extent of lowering of survival rate (χ(2)=122.920, P<0.05). CONCLUSIONS: Elevated NT-proBNP level in ICU patients signify severity of the disease, and it is an independent predictor of death of ICU patients.

Fractal scaling of particle size distribution and relationships with topsoil properties affected by biological soil crusts.

BACKGROUND: Biological soil crusts are common components of desert ecosystem; they cover ground surface and interact with topsoil that contribute to desertification control and degraded land restoration in arid and semiarid regions. METHODOLOGY/PRINCIPAL FINDINGS: To distinguish the changes in topsoil affected by biological soil crusts, we compared topsoil properties across three types of successional biological soil crusts (algae, lichens, and mosses crust), as well as the referenced sandland in the Mu Us Desert, Northern China. Relationships between fractal dimensions of soil particle size distribution and selected soil properties were discussed as well. The results indicated that biological soil crusts had significant positive effects on soil physical structure (P<0.05); and soil organic carbon and nutrients showed an upward trend across the successional stages of biological soil crusts. Fractal dimensions ranged from 2.1477 to 2.3032, and significantly linear correlated with selected soil properties (R(2) = 0.494∼0.955, P<0.01). CONCLUSIONS/SIGNIFICANCE: Biological soil crusts cause an important increase in soil fertility, and are beneficial to sand fixation, although the process is rather slow. Fractal dimension proves to be a sensitive and useful index for quantifying changes in soil properties that additionally implies desertification. This study will be essential to provide a firm basis for future policy-making on optimal solutions regarding desertification control and assessment, as well as degraded ecosystem restoration in arid and semiarid regions.