RESUMO
Assessing the quality of corn seeds necessitates evaluating their water, fat, protein, and starch content. This study integrates hyperspectral imaging technology with chemometric analysis techniques to achieve non-invasive and rapid detection of multiple key components in corn seeds. Hyperspectral images of the embryo surface of maize seeds were collected within the wavelength range of 1100~2498 nm. Subsequently, image segmentation techniques were applied to extract the germ structure of the corn seeds as the region of interest. Seven spectral data preprocessing algorithms were employed, and the Detrending Transformation (DT) algorithm was identified as the optimal preprocessing method through comparative analysis using the Partial Least Squares Regression (PLSR) model. To reduce spectral redundancy and streamline the prediction model, three algorithms were employed for characteristic wavelength extraction: Successive Projections Algorithm (SPA), Competitive Adaptive Reweighted Sampling (CARS), and Uninformative Variable Elimination (UVE). Using the original spectra and extracted characteristic wavelengths, PLSR, BP, RBF, and LSSVM models were constructed to detect the content of four components. The analysis indicated that the CARS-LSSVM algorithm had the best prediction performance. The PSO algorithm was employed to further optimize the parameters of the LSSVM model, thereby improving the model's prediction performance. The R values for the four components in the test set were 0.9884, 0.9490, 0.9864, and 0.9687, respectively. This indicates that hyperspectral technology combined with the DT-CARS-PSO-LSSVM algorithm can effectively detect the main component content of corn seeds. This study not only provides a scientific basis for the evaluation of corn seed quality but also opens up new avenues for the development of non-destructive testing technology in related fields.
Assuntos
Algoritmos , Sementes , Zea mays , Zea mays/química , Análise dos Mínimos Quadrados , Sementes/química , Imageamento Hiperespectral/métodos , Processamento de Imagem Assistida por Computador/métodos , Análise Espectral/métodosRESUMO
When the workpiece surface exhibits strong reflectivity, it becomes challenging to obtain accurate key measurements using non-contact, visual measurement techniques due to poor image quality. In this paper, we propose a high-precision measurement method shaft diameter based on an enhanced quality stripe image. By capturing two stripe images with different exposure times, we leverage their different characteristics. The results extracted from the low-exposure image are used to perform grayscale correction on the high-exposure image, improving the distribution of stripe grayscale and resulting in more accurate extraction results for the center points. The incorporation of different measurement positions and angles further enhanced measurement precision and robustness. Additionally, ellipse fitting is employed to derive shaft diameter. This method was applied to the profiles of different cross-sections and angles within the same shaft segment. To reduce the shape error of the shaft measurement, the average of these measurements was taken as the estimate of the average diameter for the shaft segment. In the experiments, the average shaft diameters determined by averaging elliptical estimations were compared with shaft diameters obtained using a coordinate measuring machine (CMM) the maximum error and the minimum error were respectively 18 µm and 7 µm; the average error was 11 µm; and the root mean squared error of the multiple measurement results was 10.98 µm. The measurement accuracy achieved is six times higher than that obtained from the unprocessed stripe images.
RESUMO
The moisture content of corn seeds is a crucial indicator for evaluating seed quality and is also a fundamental aspect of grain testing. In this experiment, 80 corn samples of various varieties were selected and their moisture content was determined using the direct drying method. The hyperspectral imaging system was employed to capture the spectral images of corn seeds within the wavelength range of 1100-2498 nm. By utilizing seven preprocessing techniques, including moving average, S-G smoothing, baseline, normalization, SNV, MSC, and detrending, we preprocessed the spectral data and then established a PLSR model for comparison. The results show that the model established using the normalization preprocessing method has the best prediction performance. To remove spectral redundancy and simplify the prediction model, we utilized SPA, CASR, and UVE algorithms to extract feature wavelengths. Based on three algorithms (PLSR, PCR, and SVM), we constructed 12 predictive models. Upon evaluating these models, it was determined that the normalization-SPA-PLSR algorithm produced the most accurate prediction. This model boasts high RC2 and RP2 values of 0.9917 and 0.9914, respectively, along with low RMSEP and RMSECV values of 0.0343 and 0.0257, respectively, indicating its exceptional stability and predictive capabilities. This suggests that the model can precisely estimate the moisture content of maize seeds. The results showed that hyperspectral imaging technology provides technical support for rapid and non-destructive prediction of corn seed moisture content and new methods in seed quality evaluation.
Assuntos
Imageamento Hiperespectral , Zea mays , Sementes , Algoritmos , Grão ComestívelRESUMO
The thermal deformation fitting result of an optical surface is an important factor that affects the reliability of optical-mechanical-thermal integrated analysis. The traditional numerical methods are challenging to balance fitting accuracy and efficiency, especially the insufficient ability to deal with high-order Zernike polynomials. In this Letter, we innovatively proposed an opto-thermal deformation fitting method based on a neural network and a transfer learning to overcome shortcomings of numerical methods. The one-dimensional convolutional neural network (1D-CNN) model, which can represent deformation of the optical surface, is trained with Zernike polynomials as the input and the optical surface sag change as the output, and the corresponding Zernike coefficients are predicted by the identity matrix. Meanwhile, the trained 1D-CNN is further combined with the transfer learning to efficiently fit all thermal deformations of the same optical surface at different temperature conditions and avoids repeated training of the network. We performed thermal analysis on the main mirror of an aerial camera to verify the proposed method. The regression analysis of 1D-CNN training results showed that the determination coefficient is greater than 99.9%. The distributions of Zernike coefficients predicted by 1D-CNN and transfer learning are consistent. We conducted an error analysis on the fitting results, and the average values of the peak-valley, root mean square, and mean relative errors of the proposed method are 51.56%, 60.51, and 45.14% of the least square method, respectively. The results indicate that the proposed method significantly improves the fitting accuracy and efficiency of thermal deformations, making the optical-mechanical-thermal integrated analysis more reliable.
RESUMO
BACKGROUND: The kidney has the highest level of selenium (Se) in the body, but the role of plasma Se in chronic kidney disease is uncertain. OBJECTIVE: We aimed to investigate the longitudinal association between baseline plasma Se and renal function decline in adults with hypertension and to explore possible effect modifiers. METHODS: This was a post hoc analysis of 935 men and women with hypertension aged 40 to 75 years from a folic-acid intervention trial (the China Stroke Primary Prevention Trial) in China. The baseline plasma Se was analyzed both as a continuous variable and as tertiles. The primary outcome was a rapid decline in renal function, defined as a mean decline in the estimated glomerular filtration rate of ≥ 5 mL/(min × 1.73 m2) per year. RESULTS: The median follow-up duration from baseline to outcome was 4.4 years. After multivariate adjustment, there was an inverse association between plasma Se and a rapid decline in renal function (per 10-unit increment; OR: 0.85; 95% CI: 0.73, 0.99). When the baseline plasma Se was assessed as tertiles, compared to the lowest tertile (<74.5 µg/L), a lower trend of the primary outcome was found in the second tertile (74.5 to < 89.4 µg/L; OR: 0.60; 95% CI: 0.34, 1.07) and the highest tertile (89.4 to <150 µg/L; OR: 0.42; 95% CI: 0.22, 0.80; Ptrend = 0.006). Furthermore, the Se-renal association was more pronounced among participants with folic acid treatment or with a higher baseline folate concentration (both Pinteraction values < 0.05). CONCLUSIONS: In this sample of Chinese adults with hypertension, baseline plasma Se concentrations were inversely associated with the risk of renal function decline. The China Stroke Primary Prevention Trial was registered at clinicaltrials.gov as NCT00794885.
Assuntos
Hipertensão , Selênio , Acidente Vascular Cerebral , Adulto , Feminino , Humanos , Masculino , China , Ácido Fólico , Taxa de Filtração Glomerular , Rim/fisiologia , Fatores de Risco , Acidente Vascular Cerebral/prevenção & controleRESUMO
BACKGROUND: The association between changes in estimated glomerular filtration rate (eGFR) over time and the risk of stroke remains inconclusive. We aimed to evaluate the relation of eGFR change during the China Stroke Primary Prevention Trial (CSPPT) with the risk of first stroke during the subsequent post-trial follow-up. METHODS: A total of 11,742 hypertensive participants with two eGFR measurements (median measure interval, 4.4; interquartile range, 4.2-4.6 years) and without a history of stroke from the CSPPT were included in this analysis. RESULTS: Over a median post-trial follow-up of 4.4 years, 729 first strokes were identified, of which 635 were ischemic, 88 were hemorrhagic, and 6 were uncertain types of strokes. Compared with those with 1 to <2% per year increase in eGFR (with the lowest stroke risk), those with an increase in eGFR of ≥4% per year had significantly increased risks of first stroke (adjusted hazard ratio [HR] 1.96; 95% confidence interval [CI], 1.10-3.50) and first ischemic stroke (adjusted HR 2.14; 95% CI, 1.17-3.90). Similarly, those with a decline in eGFR of ≥5% per year also had significantly increased first stroke (adjusted HR 2.13; 95% CI, 1.37-3.31) and first ischemic stroke (adjusted HR 1.89; 95% CI, 1.19-3.02) risk. However, there was no significant association between eGFR change and first hemorrhagic stroke. A similar result was found when the change in eGFR was quantified as an absolute annual change. CONCLUSION: In Chinese hypertensive patients, both the decline and increase of eGFR levels were independently associated with the risks of first stroke or first ischemic stroke.
Assuntos
Hipertensão , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Taxa de Filtração Glomerular , Hipertensão/epidemiologia , AVC Isquêmico/complicações , Japão , Fatores de Risco , Acidente Vascular Cerebral/epidemiologiaRESUMO
PURPOSE: We investigated the association between albuminuria and hypertensive retinopathy (HR) in hypertensive adults. METHODS: This was a cross-sectional subgroup analysis of data from the China Stroke Primary Prevention Trial. We enrolled 2,964 hypertensive adults in this study. Keith-Wagener-Barker stages was used to assess HR. The urinary albumin to creatinine ratio (UACR) was calculated to evaluate albuminuria. RESULTS: HR was found in 76.6% (n = 2, 271) of the participants, albuminuria was found in 11.1% (n = 330). The UACR levels were significantly higher in subjects with HR than in those without HR (grade 1, ß = 1.42, 95% confidence intervals [CI]: -0.12, 2.95, p = 0.070; grade 2, ß = 2.62, 95% CI: 0.56, 4.67, p = 0.013; grade 3, ß = 5.17, 95% CI: 1.13, 9.20, p = 0.012). In the subgroup analyses, the association between HR and UACR was stronger in current smokers (p for interaction = 0.014). The correlation between HR grades 1 and 2 and UACR was stronger in subjects with higher triglyceride levels (≥ 1.7 mmol/L), but for grade 3 HR, this correlation was stronger in subjects with lower triglycerides levels (< 1.7 mmol/L, p for interaction = 0.023). The odds of albuminuria were significantly higher in subjects with HR than in those without HR (grade 1, odds ratio [OR] = 1.57, 95% CI: 1.08, 2.29, p = 0.019; grade 2, OR = 2.02, 95% CI: 1.28, 3.18, p = 0.002; grade 3, OR = 2.12, 95% CI: 0.99, 4.55, p = 0.053). In the subgroup analyses, the association between HR grades 1 and 2 and albuminuria was stronger in subjects with higher triglycerides levels (≥ 1.7 mmol/L), but for grade 3 HR, this correlation was stronger in subjects with lower triglyceride levels (< 1.7 mmol/L, p for interaction = 0.014). CONCLUSION: HR was positively correlated with albuminuria in hypertensive Chinese adults. This correlation was more remarkable when the population was stratified by triglycerides levels and smoking status. HR can be used as an indicator of early renal injury.
Assuntos
Hipertensão , Retinopatia Hipertensiva , Humanos , Adulto , Albuminúria/epidemiologia , Estudos Transversais , Hipertensão/complicações , Hipertensão/epidemiologia , TriglicerídeosRESUMO
Aiming to solve the problem of color distortion and loss of detail information in most dehazing algorithms, an end-to-end image dehazing network based on multi-scale feature enhancement is proposed. Firstly, the feature extraction enhancement module is used to capture the detailed information of hazy images and expand the receptive field. Secondly, the channel attention mechanism and pixel attention mechanism of the feature fusion enhancement module are used to dynamically adjust the weights of different channels and pixels. Thirdly, the context enhancement module is used to enhance the context semantic information, suppress redundant information, and obtain the haze density image with higher detail. Finally, our method removes haze, preserves image color, and ensures image details. The proposed method achieved a PSNR score of 33.74, SSIM scores of 0.9843 and LPIPS distance of 0.0040 on the SOTS-outdoor dataset. Compared with representative dehazing methods, it demonstrates better dehazing performance and proves the advantages of the proposed method on synthetic hazy images. Combined with dehazing experiments on real hazy images, the results show that our method can effectively improve dehazing performance while preserving more image details and achieving color fidelity.
RESUMO
The Aquila Optimizer (AO) is a new bio-inspired meta-heuristic algorithm inspired by Aquila's hunting behavior. Adaptive Aquila Optimizer Combining Niche Thought with Dispersed Chaotic Swarm (NCAAO) is proposed to address the problem that although the Aquila Optimizer (AO) has a strong global exploration capability, it has an insufficient local exploitation capability and a slow convergence rate. First, to improve the diversity of populations in the algorithm and the uniformity of distribution in the search space, DLCS chaotic mapping is used to generate the initial populations so that the algorithm is in a better exploration state. Then, to improve the search accuracy of the algorithm, an adaptive adjustment strategy of de-searching preferences is proposed. The exploration and development phases of the NCAAO algorithm are effectively balanced by changing the search threshold and introducing the position weight parameter to adaptively adjust the search process. Finally, the idea of small habitats is effectively used to promote the exchange of information between groups and accelerate the rapid convergence of groups to the optimal solution. To verify the optimization performance of the NCAAO algorithm, the improved algorithm was tested on 15 standard benchmark functions, the Wilcoxon rank sum test, and engineering optimization problems to test the optimization-seeking ability of the improved algorithm. The experimental results show that the NCAAO algorithm has better search performance and faster convergence speed compared with other intelligent algorithms.
Assuntos
Águias , Animais , Algoritmos , Benchmarking , Engenharia , HeurísticaRESUMO
BACKGROUND: This study aimed to evaluate the association of serum L-carnitine with first stroke and explore potential effect modifiers. METHODS: This is a nested, case-control study drawn from the China Stroke Primary Prevention Trial among rural Chinese adults with hypertension, including 557 first stroke cases and 557 age-matched, sex-matched, treatment group-matched, and residence-matched controls. Serum L-carnitine was measured by liquid chromatography with tandem quadrupole mass spectrometry. Multiple conditional logistic regression models were used to evaluate the association between L-carnitine and first stroke. RESULTS: The mean level of serum L-carnitine in the stroke population was 4.7 µg/mL, which was significantly lower than that of the control group (5.7 µg/mL). When L-carnitine was assessed as quintiles, compared with the reference group (quintile 1, <3.3 µg/mL), the odds of stroke were 0.62 (95% CI, 0.39-1.00) in quintile 2, 0.66 (95% CI, 0.40-1.10) in quintile 3, 0.47 (95% CI, 0.28-0.81) in quintile 4, and 0.50 (95% CI, 0.30-0.84) in quintile 5. The trend test was significant (P=0.01). When quintiles 2 to 5 were combined, the adjusted odds ratio of first stroke was 0.58 (95% CI, 0.38-0.87) compared with quintile 1. Similar associations were found for ischemic stroke and hemorrhagic stroke. In subgroup analysis, a significant L-carnitine-stroke association was only observed in the normal folate group (P interaction, 0.039) and in the MTHFR CC genotype group (P interaction, 0.047). CONCLUSIONS: In this study of rural Chinese adults with hypertension, serum L-carnitine had an inverse but nonlinear association with first stroke. Folate status and the MTHFR C677T variant were significant effect modifiers of the association.
Assuntos
Hipertensão , Acidente Vascular Cerebral , Adulto , Carnitina , Estudos de Casos e Controles , China/epidemiologia , Ácido Fólico , Genótipo , Humanos , Hipertensão/complicações , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Acidente Vascular Cerebral/prevenção & controleRESUMO
OBJECTIVE: We aimed to investigate the prospective association between self-perceived psychological stress and first stroke, and to examine possible effect modifiers among adults with hypertension. METHODS: A total of 20,688 hypertensive adults with information on self-perceived psychological stress at baseline were included from the China Stroke Primary Prevention Trial. Participants were randomly assigned to a double-blind treatment of receiving a single tablet daily with either 10 mg enalapril and 0.8 mg folic acid or 10 mg enalapril alone. Follow-up visits occurred every 3 months after randomization. Psychological stress was measured with a one-item 3-point rating scale. The primary outcome was first stroke (fatal or nonfatal). RESULTS: The median treatment period was 4.5 years. Compared with participants with low levels of psychological stress, those with high psychological stress had a significantly higher risk of first stroke (adjusted hazard ratio = 1.40, 95% confidence interval = 1.01 to 1.94) or first ischemic stroke (adjusted hazard ratio = 1.45; 95% confidence interval = 1.01 to 2.09). Moreover, a stronger positive relationship between psychological stress and first stroke was found in participants with time-averaged mean arterial pressure <101 mm Hg (median; p-interaction = .004) during the treatment period. However, our study did not find a significant association between psychological stress and first hemorrhagic stroke. CONCLUSIONS: Higher psychological stress was associated with an increased risk of first stroke among treated hypertensive patients, especially in those with lower mean arterial pressure during the treatment period.
Assuntos
Hipertensão , Acidente Vascular Cerebral , Adulto , Anti-Hipertensivos/uso terapêutico , China , Método Duplo-Cego , Enalapril , Humanos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Hipertensão/epidemiologia , Estresse Psicológico/complicações , Acidente Vascular Cerebral/etiologiaRESUMO
BACKGROUND: Evidence on the association between phylloquinone status and cardiovascular diseases is scarce and conflicting. These inconsistencies may be due to differences in individual characteristics of the study populations, which may modify the association. OBJECTIVE: This study aimed to evaluate the association between plasma phylloquinone and the risk of first total stroke and its subtypes, and to examine potential effect modifications by BMI in patients with hypertension. METHODS: We performed a nested case-control study including 604 first stroke cases and 604 matched controls. The mean age was 62.2 y (range, 45 to 75). Lower BMI was defined as <25 kg/m2 and higher BMI was defined as ≥25 kg/m2. The risks of the first stroke were estimated by ORs and 95% CIs using conditional logistic regression. The primary outcome was total stroke or ischemic stroke. RESULTS: The relation between log-transformed phylloquinone concentration and stroke or ischemic stroke was modified by BMI. Higher phylloquinone concentrations were associated with lower stroke risk in those with a higher BMI. When plasma phylloquinone was assessed as tertiles, the adjusted ORs of first stroke and ischemic stroke for participants with a high BMI in tertile 2-3 were 0.70 (95% CI: 0.46, 1.08) and 0.57 (95% CI: 0.35, 0.92) compared with those in tertile 1, respectively. However, there was no significant association between plasma phylloquinone and risk of first total stroke or ischemic stroke for those with a lower BMI. Patients with a higher BMI and lower phylloquinone concentrations had the highest risk of ischemic stroke and showed a statistically significant difference compared with the reference group with a lower BMI and higher phylloquinone (OR = 1.80, 95% CI: 1.06, 3.10; P-interaction: 0.017). CONCLUSIONS: In Chinese patients with hypertension, there was an inverse association between baseline plasma phylloquinone and risk of first ischemic stroke among those with a higher BMI. This trial was registered at clinicaltrials.gov as NCT00794885.
Assuntos
Hipertensão , AVC Isquêmico , Acidente Vascular Cerebral , Adulto , Índice de Massa Corporal , Estudos de Casos e Controles , China , Humanos , Hipertensão/complicações , Pessoa de Meia-Idade , Fatores de Risco , Vitamina K 1RESUMO
BACKGROUND: Associations between vitamin D and stroke remain inconsistent. One major risk factor for stroke is high blood glucose, but the role it plays in this association is not well studied. OBJECTIVES: We aimed to evaluate the individual association between plasma 25-hydroxyvitamin D [25(OH)D] and risk of first stroke stratified by fasting blood glucose (FBG), and the joint associations between plasma 25(OH)D, glycemic status, and first stroke in hypertensive adults. METHODS: This study was a nested, case-control design utilizing data from the China Stroke Primary Prevention Trial (CSPPT). This analysis included 591 first stroke cases (of which 475 were ischemic stroke, 114 were hemorrhagic stroke, and 2 were uncertain type) and 591 matched controls. The age range of the study population was 45-75 y. The normal FBG (NFG) group had FBG <5.6 mmol/L, and the impaired FBG (IFG) group had FBG ≥5.6 mmol/L and <7.0 mmol/L. Diabetes was defined as participants with FBG ≥7 mmol/L or who were receiving treatment with hypoglycemic agents. ORs (95% CIs) were calculated using unconditional logistic regression models. RESULTS: Multivariable adjusted models revealed an inverse association between quartiles of 25(OH)D and risk of first stroke among participants with NFG, but the opposite trend was observed for those with IFG or diabetes. The largest ORs (>2) were observed among patients with diabetes, compared with the reference group of NFG and high 25(OH)D. Those with NFG and low 25(OH)D (OR = 1.73, 95% CI: 1.22 to 2.44) or those with IFG and high 25(OH)D (OR = 1.74, 95% CI: 1.14 to 2.67) both had a higher risk of total stroke. There was a significant interaction between 25(OH)D and a combined group of IFG and diabetes (P = 0.001). Similar results were observed for ischemic stroke. CONCLUSIONS: In a hypertensive population, the relation between plasma 25(OH)D and risk of first stroke was significantly modified by FBG. This trial was registered at https://www.clinicaltrials.gov as NCT00794885.
Assuntos
Hipertensão , Acidente Vascular Cerebral , Adulto , Glicemia , China/epidemiologia , Humanos , Hipertensão/epidemiologia , Prevenção Primária , Fatores de Risco , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/prevenção & controle , Vitamina D/análogos & derivadosRESUMO
Multiple-glycosylated glycosides are a major source of bioactive leads. However, most of the currently reported glycosyltransferases (GTases) mainly catalyze glycosylation of aglycones without sugar group substitution. GTases accepting diverse glycosides as substrates are rarely reported. In this article, a new GTase UGT71BD1 was identified from Cistanche tubulosa, a desert herb plant abundant with various phenylethanoid glycosides (PhGs). Interestingly, UGT71BD1 showed no activity toward the aglycone of PhGs. Instead, it could catalyze the further glycosylation of PhG compounds to produce new phenylethanoid multiglycosylated glycosides, including the natural rarely separated tetraglycoside PhGs. Extensive assays found the unprecedented substrate promiscuity of UGT71BD1 toward diverse glycosides including flavonoid glycosides, stilbene glycosides, and coumarin glycosides, performing further mono- or diglycosylation with efficient conversion rates. Using UGT71BD1, six multiglycosylated glycosides were prepared and structurally identified by NMR spectroscopy. These products showed enhanced pharmacological activities compared with the substrates. Docking, dynamic simulation, and mutagenesis studies identified key residues for UGT71BD1's activity and revealed that the sugar modules in glycosides play crucial roles in substrate recognition, thus partly illuminating the unusual substrate preference of UGT71BD1 toward diverse glycosides. UGT71BD1 could be a potential enzyme tool for glycosylation of diverse glycosides.
Assuntos
Cistanche , Cistanche/química , Cistanche/metabolismo , Glicosídeos/química , Glicosilação , Glicosiltransferases/metabolismo , AçúcaresRESUMO
BACKGROUND AND AIMS: Uncertainty remains regarding the association between the risk of stroke and plasma copper levels in population with copper mostly in normal range due to limited data. We examined the association between baseline plasma copper and risk of first stroke in Chinese community-dwelling population. METHODS: We conducted a nested case control study from 'H-type Hypertension and Stroke Prevention and Control Project'. A total of 1255 first stroke cases and 1255 controls matched for age, sex and study site were included in the analysis. Conditional logistic regression analyses were performed to evaluate the association between plasma copper and first stroke. RESULTS: The overall mean of copper was 15.90 (2.66) µmol/L. In total, 94.26% participants' copper concentration was in the normal range by Mayo Clinic laboratory reference values. Smoothing curve showed that the associations of plasma copper with first stroke and its subtypes were linear. Each standard deviation (SD) increment of plasma copper was independently and positively associated with risk of first stroke [odds ratio (OR): 1.17, 95% confidence interval (CI): 1.07-1.28]. The multivariable ORs with 95% CIs for total stroke, ischemic stroke and hemorrhagic stroke in the highest versus the lowest quartile of plasma copper were 1.49 (1.16-1.90; P-trend = 0.001), 1.46 (1.12-1.92; P-trend = 0.004) and 2.05 (0.95-4.38; P-trend = 0.050), respectively. CONCLUSIONS: Baseline plasma copper was positively associated with risk of first ischemic stroke in an approximately linear fashion among Chinese community population (80.32% hypertensives), although their copper levels were mostly within the normal range according to current reference values. Our findings warrant additional investigation.
Assuntos
Hipertensão , AVC Isquêmico , Acidente Vascular Cerebral , Estudos de Casos e Controles , Cobre , Humanos , Razão de Chances , Fatores de Risco , Acidente Vascular Cerebral/complicaçõesRESUMO
The catadioptric panoramic imaging system may provide 360° panoramic imaging by employing the convex surface of a quadric surface with rotational symmetry as the reflector, which effectively compensates for the disadvantages of the narrow field of view in typical camera systems. First, this paper proposes a theodolite-based catadioptric camera image model based on the rotational symmetry of a catadioptric camera mirror, which simplifies the 2D modeling problem to a 1D problem. Simultaneously, the equivalence of the theodolite imaging model and the standard spherical imaging model also is demonstrated in this work. Second, this paper presents a method to calibrate the theodolite model parameters using only a single view and explains the calculation of model parameter initialization and iterative optimization steps in detail. Then, this paper demonstrates how to calibrate the theodolite model parameters using only a single view, as well as how to calculate the model parameter initialization and iterative optimization steps. Finally, simulation experiments and actual experiments have confirmed the correctness and stability of the method. The experimental results show that the average and standard deviation of the back-projection error are, respectively, 0.1983125 pixels and 0.0006153 pixels, in this model. We believe the theodolite model suggested in this paper offers a viable approach to catadioptric camera image modeling.
RESUMO
PURPOSE: Visceral adiposity index (VAI) is a reliable indicator for the distribution and function of adipose tissue in the body. The relation of VAI with new-onset type 2 diabetes and new-onset impaired fasting glucose (IFG) remains uncertain. We aimed to investigate the prospective relation of VAI with new-onset type 2 diabetes and new-onset IFG in Chinese hypertensive adults. METHODS: A total of 14,838 hypertensive adults free of type 2 diabetes at baseline were included from the China Stroke Primary Prevention Trial. The primary outcome was new-onset type 2 diabetes, defined as physician-diagnosed diabetes or use of glucose-lowering drugs during follow-up, or fasting glucose ≥ 7.0 mmol/L at the exit visit. The secondary outcome was new-onset IFG, defined as fasting glucose < 6.1 mmol/L at baseline, while fasting glucose ≥ 6.1 mmol/L and < 7.0 mmol/L at the exit visit. RESULTS: Over a median of 4.5 years' follow-up, 1612 (10.9%) participants developed type 2 diabetes. When VAI was categorized into quartiles, compared with participants in quartile 1-3 (< 2.80), significantly higher risk of new-onset type 2 diabetes (OR 1.30; 95% CI 1.08-1.56) and new-onset IFG (OR 1.28; 95% CI 1.08-1.52) was found in those in quartile 4 (≥ 2.80). Moreover, the positive associations were consistent in participants with or without single abnormal VAI components, including general obesity, abdominal obesity, elevated triglycerides and low high-density lipoprotein cholesterol (HDL-C) levels; or with different numbers of abnormal VAI components (all P interactions > 0.05). CONCLUSION: Our study suggested a positive relation of VAI with the risk of new-onset type 2 diabetes and new-onset IFG in Chinese hypertensive patients, independent of its components. LEVEL OF EVIDENCE: Level III, a well-designed cohort.
Assuntos
Diabetes Mellitus Tipo 2 , Obesidade Abdominal , Adiposidade , Adulto , Glicemia , Diabetes Mellitus Tipo 2/complicações , Jejum , Glucose , Humanos , Obesidade Abdominal/complicações , Estudos Prospectivos , Fatores de RiscoRESUMO
We aimed to examine whether baseline neutrophil counts affected the risk of new-onset proteinuria in hypertensive patients, and, if so, whether folic acid treatment is particularly effective in proteinuria prevention in such a setting. A total of 8208 eligible participants without proteinuria at baseline were analysed from the renal substudy of the China Stroke Primary Prevention Trial. Participants were randomised to receive a double-blind daily treatment of 10 mg of enalapril and 0·8 mg of folic acid (n 4101) or 10 mg of enalapril only (n 4107). The primary outcome was new-onset proteinuria, defined as a urine dipstick reading of ≥1+ at the exit visit. The mean age of the participants was 59·5 (sd, 7·4) years, 3088 (37·6 %) of the participants were male. The median treatment duration was 4·4 years. In the enalapril-only group, a significantly higher risk of new-onset proteinuria was found among participants with higher neutrophil counts (quintile 5; ≥4·8 × 109/l, OR 1·44; 95 % CI 1·00, 2·06), compared with those in quintiles 1-4. For those with enalapril and folic acid treatment, compared with the enalapril-only group, the new-onset proteinuria risk was reduced from 5·2 to 2·8 % (OR 0·49; 95 % CI 0·29, 0·82) among participants with higher neutrophil counts (≥4·8 × 109/l), whereas there was no significant effect among those with neutrophil counts <4·8 × 109/l. In summary, among hypertensive patients, those with higher neutrophil counts had increased risk of new-onset proteinuria, and this risk was reduced by 51 % with folic acid treatment.
Assuntos
Enalapril , Ácido Fólico , Hipertensão , Neutrófilos/citologia , Proteinúria/prevenção & controle , Idoso , Anti-Hipertensivos/uso terapêutico , Método Duplo-Cego , Enalapril/uso terapêutico , Feminino , Ácido Fólico/uso terapêutico , Humanos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Contagem de Leucócitos , Masculino , Pessoa de Meia-IdadeRESUMO
We propose a compact dual-channel panoramic annular lens (PAL) with a large aperture and high resolution to solve three major shortcomings of conventional PAL systems: resolution, imaging quality, and compactness. Using polarization technology, the system integrates two optical channels to eliminate the central blind area. Using our PAL aperture ray-tracing model, the large aperture PAL system with a low F-number of 2.5 and a diameter ratio of 1.5 is realized. The field of view (FoV) of the front channel is 360∘×(0∘-45∘), and the FoV of the side channel is 360∘×(45∘-100∘). Both channels apply Q-type aspheres. The Airy radii of the front channel and the side channel are 1.801 and 1.798 µm, respectively. It indicates that they match the 1.8 µm pixel sensor and can form a great image on the same sensor. The modulation transfer function at 157 lp/mm is greater than 0.4 over the entire FoV. The F-θ distortion is less than 5%, and the relative illuminance is higher than 0.78 in the two channels. The excellent imaging results prove the feasibility of our PAL design method and the advantages of the compact dual-channel PAL system for space-constrained scenes.
RESUMO
BACKGROUND: According to the Global Burden of Disease Study 2017, smoking is one of the leading four risk factors contributing to deaths in China. We aimed to evaluate the associations of smoking with all-cause mortality in a Chinese rural population. METHODS: Male participants over age 45 (n = 5367) from a large familial aggregation study in rural China, were included in the current analyses. A total of 528 former smokers and 3849 current smokers accounted for 10 and 71.7% of the cohort, respectively. Generalized Estimating Equations were used to evaluate the association between baseline smoking status and mortality, adjusting for pertinent covariates. RESULTS: There were 579 recorded deaths during the 15-year follow-up. Current smokers (odds ratio [OR],1.60; 95% CI,1.23-2.08) had higher all-cause mortality risks than nonsmokers. Relative to nonsmokers, current smokers of more than 40 pack-years ([OR],1.85; 95% CI,1.33-2.56) had a higher all-cause mortality risk. Compared to nonsmokers, current smokers who started smoking before age 20 ([OR],1.91; 95% CI,1.43-2.54) had a higher all-cause mortality risk, and former smokers in the lower pack-year group who quit after age 41 (median) ([OR],3.19; 95% CI,1.83-5.56) also had a higher risk of death after adjustment. Furthermore, former smokers who were also former drinkers had the highest significant risk of mortality than never smokers or drinkers. (P for interaction = 0.034). CONCLUSIONS: This study provides evidence that current smokers and former smokers have a higher mortality risk than nonsmokers and would benefit from cessation at a younger age.