Diopter detection method based on optical imaging.

The peripheral retinal refractive state plays an important role in eye growth and development and is closely related to the development of myopia. Existing methods for measuring the peripheral retinal refractive state are cumbersome and can only detect in a limited range. To address the above shortcomings, this paper proposes a retinal refractive state detection method using optical refractive compensation imaging. First, a series of defocus images is captured using an optical system, and then the images are enhanced and filtered. Subsequently, the Sobel function is applied to calculate sharpness, and the asymmetric Gaussian (AG) model is employed for peak fitting, allowing for the determination of the fundus retina's overall refractive compensation value. We performed consistency analysis on the central and peripheral diopters with autorefractor KR-8900 (Topcon, Japan) and WAM-5500 (Grand Seiko, Japan), respectively. The intraclass correlation coefficients (ICCs) are all greater than 0.9, showing good consistency. This is a promising alternative to the current techniques for assessing the refraction of the peripheral retina.

Mechanism of wound repair in diabetic rats using nanosilver-free alginate dressing.

OBJECTIVE: Nanosilver-alginate dressing can effectively promote the healing of diabetic wounds in rats. However, due to the potential toxicity of nanosilver, its widespread application in hard-to-heal wound healing is limited. In the present study, the role and potential mechanism of nanosilver-free alginate gel (NSFAG) in the healing process of diabetic wounds were explored. METHOD: A diabetic rat skin wound model was established, and wounds were treated with saline (NC group), nanosilver gel (NSG group) or nanosilver-free alginate gel (NSFAG group) for seven consecutive days. RESULTS: NSFAG significantly promoted wound healing and increased the content of protein and hydroxyproline in granulation tissues, and was superior to NSG (p<0.05). Immunohistochemical analyses revealed that the skin wound tissue structure of the NSFAG group was intact, and the number of skin appendages in the dermis layer was significantly higher compared with the NC group and the NSG group (p<0.05). Western blot analysis found that the protein expression of the epidermal stem cell marker molecules CK19 and CK14 as well the proliferation marker of keratinocytes Ki67 in the NSFAG group was significantly higher compared with the NC group or NSG group (p<0.05). Additionally, the proliferation marker of keratinocytes Ki67 in the NSFAG group was significantly higher compared with the NC or NSG group (p<0.05). Immunofluorescence staining analyses indicated that the CK19- and CK14-positive cells were mainly distributed around the epidermis and the newly formed appendages in the NSFAG group, and this result was not observed in the NC or NSG groups. CONCLUSION: The present findings demonstrate that NSFAG can effectively accelerate wound healing in diabetic rats by promoting epidermal stem cell proliferation and differentiation into skin cells, as well as formation of granulation tissue, suggesting that it can be a potential dressing for diabetic wounds.

Downregulation of hsa-miR-203 in peripheral blood and wound margin tissue by negative pressure wound therapy contributes to wound healing of diabetic foot ulcers.

Negative pressure wound therapy (NPWT) has been widely used in the treatment of chronic wounds, including diabetic foot ulcers (DFU) as the severe manifestation of diabetic foot. Hsa-miR-203 is proven to be correlated with the severity of DFU. To investigate whether NPWT influences hsa-miR-203 levels in persons with DFU, we detected hsa-miR-203 levels in peripheral plasma and wound margin tissue from the following patients: type 2 diabetic (T2D) patients with DFU (DFU group), T2D patients without DFU (NDFU group), patients with chronic skin ulcer and normal glucose tolerance (SUC group), and healthy volunteers with normal glucose tolerance (NC group). All patients in SUC group received NPWT. As contrast, some of patients in DFU group received NPWT (NPWT group) while others chose routine dressing therapy (non-NPWT group). In vitro experiments were also performed to determine influences of negative pressure on cell proliferation and migration of HaCaT cells (human keratinocytes). Results showed that before NPWT, levels of hsa-miR-203 in peripheral plasma (P-miR-203) and wound margin tissue (T-miR-203) of DFU group were obviously increased compared to SUC group while expression of P-miR-203 decreased in NDFU group compared with NC group. After NPWT, levels of P-miR-203 and T-miR-203 in DFU and SUC group were significantly lower than before. Changes of P-miR-203 and T-miR-203 after NPWT were positively correlated with 4-week ulcer healing rate in NPWT and SUC group. In vitro, negative pressure lowered the expression of hsa-miR-203, enhancing cell proliferation and migration in HaCaT cells via up-regulation of p63 protein. Meanwhile, the effects of negative pressure on cells were remarkable reduced by high-glucose intervention. Our study suggests that NPWT promotes DFU healing by reducing the expression of hsa-miR-203 in peripheral blood and wound tissue. The changes of hsa-miR-203 in peripheral blood and wound tissue may be related to the therapeutic effect of NPWT.

Temporary Actuation of Bilayer Polymer Hydrogels Mediated by the Enzymatic Reaction.

Most soft actuators have the ability of monotonic responsiveness. That is, there is only one response action after being stimulated once. In this work, a temporarily responsive bilayer hydrogel actuator is designed and fabricated by combining a tertiary amine-containing pH-responsive layer and a urease-containing non-responsive layer. The hydrogel actuator can achieve programed deformation and recovery driven by chemical fuels (i.e., acidic urea solutions), which is essentially regulated by rapid acidification and slow enzymatic production of ammonia for recovering the pH of the system. The actuation extent and duration can be simply controlled by the fuel levels, and the repeated actuations are also possible via refueling. Furthermore, we fabricate several hydrogel devices that can display specific patterns or lift an item. This enzymatic method shows new possibilities to control the temporary actuation of polymer hydrogels potentially useful in many fields such as soft robotics, biomimetic devices, and environmental sensing.

Spatiotemporal changes in aerosols over Bangladesh using 18 years of MODIS and reanalysis data.

In this study, combined Dark Target and Deep Blue (DTB) aerosol optical depth at 550 nm (AOD550 nm) data the Moderate Resolution Imaging Spectroradiometer (MODIS) flying on the Terra and Aqua satellites during the years 2003-2020 are used as a reference to assess the performance of the Copernicus Atmosphere Monitoring Services (CAMS) and the second version of Modern-Era Retrospective analysis for Research and Applications (MERRA-2) AOD over Bangladesh. The study also investigates long-term spatiotemporal variations and trends in AOD, and determines the relative contributions from different aerosol species (black carbon: BC, dust, organic carbon: OC, sea salt: SS, and sulfate) and anthropogenic emissions to the total AOD. As the evaluations suggest higher accuracy for CAMS than for MERRA-2, CAMS is used for further analysis of AOD over Bangladesh. The annual mean AOD from both CAMS and MODIS DTB is high (>0.60) over most parts of Bangladesh except for the eastern areas of Chattogram and Sylhet. Higher AOD is observed in spring and winter than in summer and autumn, which is mainly due to higher local anthropogenic emissions during the winter to spring season. Annual trends from 2003-2020 show a significant increase in AOD (by 0.006-0.014 year-1) over Bangladesh, and this increase in AOD was more evident in winter and spring than in summer and autumn. The increasing total AOD is caused by rising anthropogenic emissions and accompanied by changes in aerosol species (with increased OC, sulfate, and BC). Overall, this study improves understanding of aerosol pollution in Bangladesh and can be considered as a supportive document for Bangladesh to improve air quality by reducing anthropogenic emissions.

Development of a non-invasive method for skin cholesterol detection: pre-clinical assessment in atherosclerosis screening.

BACKGROUND: Establishing a high-accuracy and non-invasive method is essential for evaluating cardiovascular disease. Skin cholesterol is a novel marker for assessing the risk of atherosclerosis and can be used as an independent risk factor of early assessment of atherosclerotic risk. METHODS: We propose a non-invasive skin cholesterol detection method based on absorption spectroscopy. Detection reagents specifically bind to skin cholesterol and react with indicator to produce colored products, the skin cholesterol content can be obtained through absorption spectrum information on colored products detected by non-invasive technology. Gas chromatography is used to measure cholesterol extracted from the skin to verify the accuracy and reliability of the non-invasive test method. A total of 342 subjects were divided into normal group (n = 115), disease group (n = 110) and risk group (n = 117). All subjects underwent non-invasive skin cholesterol test. The diagnostic accuracy of the measured value was analyzed by receiver-operating characteristic (ROC) curve. RESULTS: The proposed method is able to identify porcine skin containing gradient concentration of cholesterol. The values measured by non-invasive detection method were significantly correlated with gas chromatography measured results (r = 0.9074, n = 73, p < 0.001). Bland-Altman bias was - 72.78 ± 20.03 with 95% limits of agreement - 112.05 to - 33.51, falling within the prespecified clinically non-significant range. We further evaluated the method of patients with atherosclerosis and risk population as well as normal group, patients and risk atherosclerosis group exhibited higher skin cholesterol content than normal group (all P < 0.001). The area under the ROC curve for distinguishing Normal/Disease group was 0.8642 (95% confidence interval, 0.8138 to 0.9146), meanwhile, the area under the ROC curve for distinguishing Normal/Risk group was 0.8534 (95% confidence interval, 0.8034 to 0.9034). CONCLUSIONS: The method demonstrated its capability of detecting different concentration of skin cholesterol. This non-invasive skin cholesterol detection system may potentially be used as a risk assessment tool for atherosclerosis screening, especially for a large population.

Assessment the reliability of ultrasonography in the imaging of the plantar fascia: a comparative study.

BACKGROUND: Imaging methods for the plantar fascia have included radiography, ultrasound and magnetic resonance imaging (MRI), all of which have provided valuable information. This study assessed the reliability of ultrasonography examinations of the plantar fascia using a comparative study. METHODS: Fifty healthy adult volunteers (25 males and 25 females, mean age 31.6 ± 3.5 years) were included in this study. Images of the plantar fascia from 100 ft were acquired with ultrasonography, CT and MRI. Ultrasound was used to measure the thickness of the plantar fascia. Imaging data from CT and MRI in a DICOM format were transformed into the Materialise Mimics Innovation Suite 16.0 software for digital analysis. SPSS software (SPSS, USA) was used for statistical analysis. The reliability was established by a t-test. Moreover, 42 patients with unilateral plantar fasciitis were examined by ultrasonography. RESULTS: There were no significant differences between the three imaging modalities for patients of the same sex (P > 0.05). There were no statistically significant differences between the left and right sides for patients of the same sex (P > 0.05), but the difference between males and females was statistically significant (P < 0.01). There were no significant differences between US, CT and MRI in the normal group, but there were significant differences in the plantar fasciitis group evaluated with ultrasound. The plantar fascii of normal male subjects are significantly thicker than those of the normal female. CONCLUSION: Ultrasonography can be a relatively simple and reliable method for the measurement of plantar fascia thickness.

Rapid Invasion of Spartina Alterniflora in the Coastal Zone of Mainland China: Spatiotemporal Patterns and Human Prevention.

Given the extensive spread and ecological consequences of exotic Spartina alterniflora (S. alterniflora) over the coast of mainland China, monitoring its spatiotemporal invasion patterns is important for the sake of coastal ecosystem management and ecological security. In this study, Landsat series images from 1990 to 2015 were used to establish multi-temporal datasets for documenting the temporal dynamics of S. alterniflora invasion. Our observations revealed that S. alterniflora had a continuous expansion with the area increasing by 50,204 ha during the considered 25 years. The largest expansion was identified in Jiangsu Province during the period of 1990-2000, and in Zhejiang Province during the periods 2000-2010 and 2010-2015. Three noticeable hotspots for S. alterniflora invasion were Yancheng of Jiangsu, Chongming of Shanghai, and Ningbo of Zhejiang, and each had a net area increase larger than 5000 ha. Moreover, an obvious shrinkage of S. alterniflora was identified in three coastal cities including the city of Cangzhou of Hebei, Dongguan, and Jiangmen of Guangdong. S. alterniflora invaded mostly into mudflats (>93%) and shrank primarily due to aquaculture (55.5%). This study sheds light on the historical spatial patterns in S. alterniflora distribution and thus is helpful for understanding its invasion mechanism and invasive species management.

Island soil quality assessment and the relationship between soil quality and land-use type/topography.

Information about the soil quality of different land-use types and topographies is essential for the sustainable development, utilization, and protection of soil resource in coastal areas. In this study, representative topsoil samples were collected from Liandao Island, China, and soil water content (SWC), soil bulk density (BD), total nitrogen (TN), soil organic matter (SOM), ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3--N), available phosphorus (AP), available potassium (AK), soil salt content (SSC), and pH were recorded. The suitable minimum soil data set (MDS) was computed by principal component analysis (PCA) and the soil quality index (SQI) was then determined. The spatial distribution of the SQI was analyzed using ordinary kriging interpolation. The effects of topographical parameters (digital elevation model [DEM], slope, and aspect) and land-use types (vegetation [V], water resource conservancy land [WRC], sandy land [SL], unused land [UL], and built-up land [BL]) on SQI were then analyzed in detail. The parameters included in the MDS were TN, pH, and BD, which together accounted for 84.371% of the variation in soil quality. The SQI varied from 0.189 to 0.772 in the study area. The correlation coefficients between SQI and DEM, slope, and aspect were 0.498, 0.294, and 0.137, respectively (p < 0.01). The highest SQI score was found at an elevation of 110 m, with a slope of 68.2° and an aspect of 246.6, in the vegetation land-use type. Soil quality differed significantly (p = 0.0000) among the land-use types, with the following ranking: V > UL > SL > BL. Our results provide land managers with an important reference for the development, utilization, and protection of soil resource in coastal zones such as Liandao Island, China.

[Spectral Feature and Mg Number (Fo#) Analysis of Olivine in Sinus Iridium].

The research on the distribution and component of olivine is one of great significance to evaluate the geologic evolution of igneous planetary bodies such as the Moon. In this paper, the Sinus Iidium, as the survey region, was explored by Chang's serial satellite. Here we present an olivine survey of the Sinus Iridium by using Spectral Feature Fitting (SFF) method based on the M3 data. The exposures of olivine were located in the northern crater wall and at the foot of Montes Jura, which were associated with plagioclase and little anorthosite. The stratigraphic units of the located formation were the interior crater slopes and debris ejected from the impact-formed Iridium crater, and the geological age was relatively older. The Mg number of the lunar olivine samples was dependent variables, and the band center of the lunar olivine spectrums were independent, which derived from the fitting analysis using Modified Gaussian Model (MGM). The quantitative inversion models of Mg number (Fo#) of the lunar olivine is established with multiple linear regression analysis. On this basis, the Mg number of the olivine rich point in the Sinus Iridium are calculated with quantitative inversion models of Mg number (Fo#). The result shows that, the Fo# of olivine in the Sinus Iridium are relatively high. The mean value of Fo# is Fo~80.84. As mantle olivine would be expected to be quite Mg-rich, it is suggested that at the vast majority of the olivine detected in the Sinus Iridium come from upper mantle of the Moon.

[Tissue Intrinsic Fluorescence Spectrum Recovering Based on Diffusion Theory].

Tissue intrinsic fluorescence spectrum refers to the fluorescence that is not impaired by tissue absorption and scattering which has the ability to reflect tissue biochemical properties. In order to reduce the influence of tissue absorption and scattering properties on tissue fluorescence spectrum, and then recover tissue intrinsic fluorescence spectrum, a tissue spectrum detection system based on fiber-optic probe was developed for the measurement of tissue fluorescence spectrum and diffusion reflectance spectrum at the same place. On the other hand, diffusion theory was introduced to extract the tissue physiological parameters from the measurement tissue diffusion reflectance spectrum, which included blood volume fraction, oxyhemoglobin saturation, melanin content, reduce scattering coefficient at 500 nm and the ratio of rayleigh scattering and the total scattering. Then tissue optical parameters in visible wavelengths were calculated. According to the tissue optical parameters and measured tissue diffusion spectrum, the intrinsic fluorescence spectrum was recovered from the measured fluorescence. Based on this, clinical trials were conducted to measure human skin fluorescence spectrum and diffusion reflectance spectrum, and then to recover skin intrinsic fluorescence spectrum. Finally, the accumulation of Advanced Glycation End products (AGE) in human skin was evaluated and the probability of diabetes mellitus was predicted. The result shows that the sensitivity and specificity were 69% and 0.75% respectively, when the measured fluorescent was used to screening diabetes mellitus. At the same specificity, the sensitivity was 90% when the recovered intrinsic fluorescence was employed to screening diabetes mellitus.

Synthesis, resolution and biological evaluation of cyclopropyl analogs of abscisic acid.

cis-2,3-Cyclopropanated abscisic acid (cis-CpABA) has high photostability and good ABA-like activity. To further investigate its activity and action mechanism, 2S,3S-2,3-cyclopropanated ABA (3a) and 2R,3R-2,3-cyclopropanated ABA (3b) were synthesized. Bioassay showed that 3a displayed higher inhibitory activity in germination than that of 3b and ABA at the concentration of 3.0 µM, but 3a and 3b had much weaker inhibitory activity in inhibition seedling growth compared to ABA. The study of photostability revealed that 3a and 3b showed high stability under UV light exposure, which were 4 times and 3 times greater than (±)-ABA, respectively. Action mechanism study showed that 3a presented higher inhibition on phosphatase activity of HAB1 than 3b, although they all inferior to ABA. Molecular docking studies of 3a, 3b and ABA receptor PYL10 were agreement with the bioassay data and confirmed the importance of the configuration of the 2,3-cyclopropyl ABA analogs for their bioactivity in somewhat. This study provides a new approach for the design of ABA analogs, and the results validated structure-based design for this target class.

Particle size distribution of river-suspended sediments determined by in situ measured remote-sensing reflectance.

Suspended sediments in water bodies are classified into organic and inorganic matter and have been investigated by remote-sensing technology for years. Focusing on inorganic matter, however, detailed information such as the grain size of this matter has not been provided yet. In this study, we present a new solution for estimating inorganic suspended sediments' size distribution in highly complex Case 2 waters by using a simple spectrometer sensor rather than a backscattering sensor. An experiment was carried out in the Pearl River Estuary (PRE) in the dry season to collect the remote-sensing reflectance (Rrs) and particle size distribution (PSD) of inorganic suspended sediments. Based on Mie theory, PSDs in the PRE waters were retrieved by Rrs, colored dissolved organic matter, and phytoplankton. The retrieved median diameters in 12 stations show good agreement with those of laboratory analysis at root mean square error of 2.604 µm (27.63%), bias of 1.924 µm (20.42%), and mean absolute error of 2.298 µm (24.37%). The retrieved PSDs and previous PSDs were compared, and the features of PSDs in the PRE waters were concluded.

Development of noninvasive prenatal diagnosis of trisomy 21 by RT-MLPA with a new set of SNP markers.

INTRODUCTION: Placental mRNA can now be detected in maternal whole blood, raising the possibility of using maternal blood for noninvasive prenatal diagnosis (NIPD) of trisomy 21. We aimed to identify new mRNA-single nucleotide polymorphism (mRNA-SNP) markers suitable for use in reverse-transcriptase multiplex ligation-dependent probe amplification (RT-MLPA) to develop a more reliable diagnostic method for trisomy 21 in Chinese subjects. MATERIALS AND METHODS: Using sequencing, we determined the status of SNPs in genes expressed in the placenta and calculated their heterozygote frequencies to determine which loci were suitable for use in RT-MLPA. Cell-free fetal RNA was extracted from peripheral blood samples of 246 women at 12-24 weeks of pregnancy, and the SNP loci selected were analyzed by RT-MLPA, followed by capillary electrophoresis. Karyotype analyses were used to confirm the diagnosis of trisomy 21. RESULTS: As compared with karyotype analysis, the diagnostic sensitivity and specificity of RT-MLPA were excellent (95 and 100% in different gestational weeks). CONCLUSION: The RT-MLPA technique is a suitable and reliable method for the diagnosis of trisomy 21. Use of RT-MLPA with the SNP markers described here shows good specificity, high sensitivity, and high throughput potential, making this technique suitable for NIPD in clinical practice.

[Research on noninvasive risk evaluation of diabetes mellitus based on neural network pattern recognition].

Advanced glycation end products (AGEs) are highly associated with hyperglycemia in human skin tissue, and they also have the autofluorescence characteristic. A self-developed optical noninvasive detection device was used to measure the autofluorescence in human skin tissue, and then a neural network pattern recognition model was used to assess the risk of diabetes mellitus of the subject under survey. After the fluorescence spectra were acquired and processed with principal component analysis, four of the leading principal components were chosen to represent a whole spectrum. The established neural network pattern recognition model has 4 input nodes, 6 hidden nodes and 1 output node. A dataset consisting of 487 cases collected in Anhui Provincial Hospital was used to train the model. Seventy percent cases were used as the training set, 15% as the validation set and 15% as the test set. The model can output subject's risk of diabetes mellitus, or a dichotomous judgment. Receiver operating characteristic curve can be drawn with the area under curve of 0. 81, with standard error of 0. 02. When using 0. 5 as the threshold between diabetes mellitus and non-diabetes mellitus, the sensitivity and specificity of this model is 72. 4% and 77. 6% respectively, and the overall accuracy is 74. 9%. The method using human skin autofluorescence spectrum combined with neural network pattern recognition model is proposed for the first time, and the results show that this method has a better screening effect compared with currently used fasting plasma glucose and HbAlc.

Noninvasive detection of diabetes mellitus based on skin fluorescence and diffuse reflectance spectroscopy.

There is an urgent need for a mass population screening tool for diabetes. Skin tissue contains a large number of endogenous fluorophores and physiological parameter markers related to diabetes. We built an excitation-emission spectrum measurement system with the excited light sources of 365, 395, 415, 430, and 455 nm to extract skin characteristics. The modeling experiment was carried out to design and verify the accuracy of the recovery of tissue intrinsic discrete three-dimensional fluorescence spectrum. Blood oxygen modeling experiment results indicated the accuracy of the physiological parameter extraction algorithm based on the diffuse reflectance spectrum. A community population cohort study was carried out. The tissue-reduced scattering coefficient and scattering power of the diabetes were significantly higher than normal control groups. The Gaussian multi-peak fitting was performed on each excitation-emission spectrum of the subject. A total of 63 fluorescence features containing information such as Gaussian spectral curve intensity, central wavelength position, and variance were obtained from each person. Logistic regression was used to construct the diabetes screening model. The results showed that the area under the receiver operating characteristic curve of the model for predicting diabetes was 0.816, indicating a high diagnostic value. As a rapid and non-invasive detection method, it is expected to have high clinical value.

Improving performance of medical image alignment through super-resolution.

Medical image alignment is an important tool for tracking patient conditions, but the quality of alignment is influenced by the effectiveness of low-dose Cone-beam CT (CBCT) imaging and patient characteristics. To address these two issues, we propose an unsupervised alignment method that incorporates a preprocessing super-resolution process. We constructed the model based on a private clinical dataset and validated the enhancement of the super-resolution on alignment using clinical and public data. Through all three experiments, we demonstrate that higher resolution data yields better results in the alignment process. To fully constrain similarity and structure, a new loss function is proposed; Pearson correlation coefficient combined with regional mutual information. In all test samples, the newly proposed loss function obtains higher results than the common loss function and improve alignment accuracy. Subsequent experiments verified that, combined with the newly proposed loss function, the super-resolution processed data boosts alignment, can reaching up to 9.58%. Moreover, this boost is not limited to a single model, but is effective in different alignment models. These experiments demonstrate that the unsupervised alignment method with super-resolution preprocessing proposed in this study effectively improved alignment and plays an important role in tracking different patient conditions over time.

Trace elements in surface sediments from Xinyanggang River of Jiangsu Province, China: Spatial distribution, risk assessment and source appointment.

The Xinyanggang River in Yancheng City, one of the essential rivers entering the Yellow sea, has imported abundant pollutants to the coast of Jiangsu Province. Trace elements (Cr, Ni, Cu, Zn, As, Rb, Sr, Mo, Pb, Th, U, Sc, Ga, Se, Zr, Nb, and Sn) in surface sediments in the Xinyanggang River were measured to analyze the spatial distribution, risk assessment, and source appointment. The results showed that the parts of 17 trace elements presented high average values in river sediments, such as Zr (309.19 mg/kg), Sr (182.72 mg/kg), Zn (77.67 mg/kg), and Cr (70.63 mg/kg). Compared with some coastal rivers, the Xinyanggang River was polluted by certain trace elements, such as Cr, Zn, and As. Based on the analysis of the enrichment factor (EF), the contamination factor (CF), the pollution load index (PLI), and the geoaccumulation index (Igeo), trace elements in sediments showed unpolluted to moderate contamination and mild to moderate enrichment. Among them, Zn, Pb, and Sn were highly polluted. The multivariate analysis, the principal component analysis-multiple linear regression (APCS-MLR) model, and the Unmix model identified four contributing trace element sources. Cr, Th, U, Se, Zr, and Nb originated from manufacturing industries and hydrodynamic transport erosion. Ni, Rb, Sc, and Ga were attributed to natural source. Cu, Zn, Mo, Pb, and Sn were contributed from mixed sources including industrial wastewater and transportation emissions. As and Sr were associated mainly with mixed sources of agriculture and combustion. These four sources of metals accounted for 22.5 %, 5.7 %, 15.3 %, and 11.1 % by using the APCS-MLR model, whereas 22.9 %, 39.7 %, 17.5 %, and 19.9 % by using the Unmix model, respectively.

Enhancement of cone beam CT image registration by super-resolution pre-processing algorithm.

In order to enhance cone-beam computed tomography (CBCT) image information and improve the registration accuracy for image-guided radiation therapy, we propose a super-resolution (SR) image enhancement method. This method uses super-resolution techniques to pre-process the CBCT prior to registration. Three rigid registration methods (rigid transformation, affine transformation, and similarity transformation) and a deep learning deformed registration (DLDR) method with and without SR were compared. The five evaluation indices, the mean squared error (MSE), mutual information, Pearson correlation coefficient (PCC), structural similarity index (SSIM), and PCC + SSIM, were used to validate the results of registration with SR. Moreover, the proposed method SR-DLDR was also compared with the VoxelMorph (VM) method. In rigid registration with SR, the registration accuracy improved by up to 6% in the PCC metric. In DLDR with SR, the registration accuracy was improved by up to 5% in PCC + SSIM. When taking the MSE as the loss function, the accuracy of SR-DLDR is equivalent to that of the VM method. In addition, when taking the SSIM as the loss function, the registration accuracy of SR-DLDR is 6% higher than that of VM. SR is a feasible method to be used in medical image registration for planning CT (pCT) and CBCT. The experimental results show that the SR algorithm can improve the accuracy and efficiency of CBCT image alignment regardless of which alignment algorithm is used.

Exploration of 2D and 2.5D Conformational Designs Applied on Epoxide/Collagen-Based Integrative Biointerfaces with Device/Tissue Heterogeneous Affinity.

Collagen and multifunctional epoxides, which are respectively the common constituents of natural and polymer interfaces, were combined to fabricate integrative biointerfaces with device/tissue heterogeneous affinity. Further, the traditional 2D and advanced 2.5D conformational designs were achieved on collagen-based biointerfaces. The 2D conformational biointerfaces were formed by the self-entanglement of collagen molecules based on extensive hydrogen bonds among molecules, and the lamellar structures of 2D conformational biointerfaces could act as barriers to protect both biointerfaces and substrates from enzymes and corrosion. The unique stacking structures of 2.5D conformational biointerfaces were formed by cross-linking microaggregates that were established and connected by epoxy cross-linking bonds and provided the extra 0.5D degree of freedom on structure design and functional specialization through artificially manipulating the constituents and density of microaggregates. Besides, the intersecting channels among microaggregates gave 2.5D biointerfaces diffusion behaviors, which further brought good wettability and biodegradability. The integrative biointerfaces behaved well on cell viability and enhanced the cell adhesion strength in vitro, which could be attributed to the collaborations of collagen and epoxy groups. The subcutaneous implant model in rats was utilized to investigate soft tissue response, and the results demonstrated that the tissues around implantation areas healed well and without calcification or infection. The coating of integrative biointerfaces alleviated the fibrosis around implantation areas, and the inflammatory responses and foreign body reactions were improved.