Accuracy Assessment of Geometric-Distortion Identification Methods for Sentinel-1 Synthetic Aperture Radar Imagery in Highland Mountainous Regions.

SAR imagery plays a crucial role in geological and environmental monitoring, particularly in highland mountainous regions. However, inherent geometric distortions in SAR images often undermine the precision of remote sensing analyses. Accurately identifying and classifying these distortions is key to analyzing their origins and enhancing the quality and accuracy of monitoring efforts. While the layover and shadow map (LSM) approach is commonly utilized to identify distortions, it falls short in classifying subtle ones. This study introduces a novel LSM ground-range slope (LG) method, tailored for the refined identification of minor distortions to augment the LSM approach. We implemented the LG method on Sentinel-1 SAR imagery from the tri-junction area where the Xiaojiang, Pudu, and Jinsha rivers converge at the Yunnan-Sichuan border. By comparing effective monitoring-point densities, we evaluated and validated traditional methods-LSM, R-Index, and P-NG-against the LG method. The LG method demonstrates superior performance in discriminating subtle distortions within complex terrains through its secondary classification process, which allows for precise and comprehensive recognition of geometric distortions. Furthermore, our research examines the impact of varying slope parameters during the classification process on the accuracy of distortion identification. This study addresses significant gaps in recognizing geometric distortions and lays a foundation for more precise SAR imagery analysis in complex geographic settings.

Risk assessment and prevention of urolithiasis in urban areas of Baoding, China.

Urolithiasis, or the formation of calculi in the urinary system, represents a prevalent urological condition frequently encountered among individuals aged 30 to 55 years. An in-depth analysis of the composition of these calculi holds significant promise in shedding light on the underlying etiological and pathogenic factors contributing to this ailment. The primary objective of this study was to delineate the principal components comprising urinary system calculi within a cohort of patients who sought medical intervention at a tertiary grade A hospital located in Baoding City. Furthermore, our investigation entailed a comprehensive examination of the physical and morphological characteristics exhibited by these calculi. In this study, a total of 2307 individuals afflicted with urinary system calculi were recruited as participants, and a corresponding number of 2307 calculous specimens were subjected to thorough examination. The specimens were examined using infrared spectroscopy. We collected and examined patient data including gender, age, location of the calculi, employment status, residential area, and other factors. The middle-aged demographic exhibited a conspicuous predilection for urinary system calculi, wherein a notable gender disparity was observed, with a male-to-female ratio of 1.63 to 1. Among the enrolled patients, kidney calculi were prevalent in 1270 cases, ureteral calculi were documented in 983 cases, and bladder calculi were encountered in 46 instances. Notably, the principal components comprising these calculi were identified as calcium oxalate and apatite, while uric acid and ammonium magnesium phosphate were comparatively less frequently encountered. Furthermore, the analysis of calculus composition across patients residing in distinct geographical regions did not reveal any statistically significant variations. The identification of components within upper urinary tract calculi plays a pivotal role in elucidating the root causes of calculus formation. This valuable information empowers healthcare professionals, particularly nursing staff, to provide personalized dietary and health guidance to patients, thereby enhancing the quality of care and promoting more effective management of this condition.

Stability and ecological risk assessment of nickel (Ni) in phytoremediation-derived biochar.

Improper treatment of heavy metal-enriched biomass generated after phytoremediation might cause secondary pollution in soil and water. At present, the pyrolysis process is an effective method for the treatment of phytoremediation residue. In this study, Ni-enriched biomass was prepared using hydroponics method and further pyrolyzed at different temperatures (300-700 °C). At low pyrolysis temperatures (below 500 °C), carbonate precipitation was the main reason of Ni stabilization in biochar. Nevertheless, the formed phosphate and aluminosilicate were important factors for immobilizing Ni in biochar at high pyrolysis temperatures (above 500 °C). Moreover, the oxidizable (F3) and residual (F4) components of Ni in biochar increased with increasing pyrolysis temperature, which indicated that higher pyrolysis temperature could effectively reduce the bioavailability of Ni in biochar. The results of deionized water, acidification, oxidation, and toxic characteristic leaching procedure (TCLP) experiments showed that pyrolysis temperature was the dominant factor for Ni stabilization in biochar. The ecological risk assessments further proved that pyrolyzed Ni-enriched biochar could reduce the environmental toxicity and potential ecological risks of Ni. In the soil simulated experiment, the soil microenvironment gradually promoted the transformation of Ni in BCNiX from bioavailable fraction to stable fraction. Overall, this study would expose more reasonable reference for the long-term storage of phytoremediation residues.

Coupling coordination relationship between geology-geomorphology and ecology in Northeast China.

Northeast China is an important ecological barrier and commodity grain base in China. The coupling coordination relationship between geology-geomorphology and ecology has become a critical background condition for ecosystem protection and sustainable development. Taking Northeast China as a case (accounting for about 13% of China's land area), 9 divisions are divided according to the characteristics of regional ecology and geology-geomorphology, and 17 indicators are selected to build an evaluation index system. Methods of analytic hierarchy process, entropy weight and game theory are used to determine the index weights. Based on the coupling coordination degree (CCD) model, the spatial coupling coordination characteristics of geology-geomorphology and ecology are studied. The variation characteristics of the Normalized Difference Vegetation Index (NDVI) are evaluated by Sen+Mann-Kendall (Sen+MK) method. Our results are as follows. (1) The coupling between geology-geomorphology and ecology is strong, but the spatial differentiation of CCD is obvious. Nine divisions are evaluated as two high-level, three medium-level and three low-level coordination types and one mild imbalance type. (2) The plain divisions Ⅰ and Ⅳ where the typical black soil belt is located are high coordination types. Restricted by geology-geomorphological conditions or ecological conditions, mountain divisions Ⅲ and Ⅶ and plain division Ⅴ are moderate coordination types, mountain divisions Ⅱ and Ⅷ and plateau division Ⅸ are low coordination types, and mountain division Ⅵ is mild imbalance type. (3) The variation trend of NDVI shows a significant increase in divisions Ⅲ, Ⅴ, Ⅰ, Ⅱ and Ⅶ. it shows a significant decrease in part of divisions Ⅳ, Ⅵ, Ⅷ and Ⅸ, and ecological management and construction should be strengthened in these divisions. The research shows that the CCD model method is feasible for evaluating the relationship between geology-geomorphology and ecology and can provide eco-geological background information for Northeast China.

Electric field-induced chiral d + id superconductivity in AA-stacked bilayer graphene: a quantum Monte Carlo study.

Using the constrained-path quantum Monte Carlo method, we systematically study the half-filled Hubbard model on AA-stacked honeycomb lattice. Our simulations demonstrate that a dominant chiral d + id wave superconductivity can be induced by a perpendicular electric field. At a fixed electric field, the effective pairing interaction of chiral d + id superconductivity exhibits an increasing behavior with increasing the on-site Coulomb interaction. We attribute the electric field-induced d + id superconductivity to an increased density of states near the Fermi energy and robust antiferromagnetic spin correlation upon turning on electric field. Our results strongly suggest that the AA-stacked graphene system is a good candidate for chiral d + id superconductor.

Accurate, rapid and low-cost diagnosis of Mycoplasma pneumoniae via fast narrow-thermal-cycling denaturation bubble-mediated strand exchange amplification.

Mycoplasma pneumoniae is a strong infectious pathogen that may cause severe respiratory infections. Since this pathogen may possess a latent period after infection, which sometimes leads to misdiagnosis by traditional diagnosis methods, the establishment of a rapid and sensitive diagnostic method is crucial for transmission prevention and timely treatment. Herein, a novel detection method was established for M. pneumoniae detection. The method, which improves upon a denaturation bubble-mediated strand exchange amplification (SEA) that we developed in 2016, is called accelerated SEA (ASEA). The established ASEA achieved detection of 1% M. pneumoniae genomic DNA in a DNA mixture from multiple pathogens, and the limit of detection (LOD) of ASEA was as low as 1.0 × 10-17 M (approximately 6.0 × 103 copies/mL). Considering that the threshold of an asymptomatic carriage is normally recommended as 1.0 × 104 copies/mL, this method was able to satisfy the requirement for practical diagnosis of M. pneumoniae. Moreover, the detection process was finished within 20.4 min, significantly shorter than real-time PCR and SEA. Furthermore, ASEA exhibited excellent performance in clinical specimen analysis, with sensitivity and specificity of 96.2% and 100%, respectively, compared with the "gold standard" real-time PCR. More importantly, similar to real-time PCR, ASEA requires only one pair of primers and ordinary commercial polymerase, and can be carried out using a conventional fluorescence real-time PCR instrument, which makes this method low-cost and easy to accomplish. Therefore, ASEA has the potential for wide use in the rapid detection of M. pneumoniae or other pathogens in large numbers of specimens. Graphical abstract.

Integrated silica membrane-based nucleic acid purification, amplification, and visualization platform for low-cost, rapid detection of foodborne pathogens.

Real-time fluorescence detection of nucleic acid exhibit excellent performance in analytical and diagnostic applications. However, the requirement of laboratory-based instrument and complex nucleic acid extraction greatly limits their application in point-of-care testing (POCT). Herein, a novel integrated silica membrane-based platform incorporating nucleic acid purification, amplification, and detection steps was developed. A universal and portable visualization platform was fabricated by incorporating denaturation bubble-mediated strand exchange amplification (SEA) reaction with silica membrane. The fluorescence signal of SYBR Green I with amplification products was visualized by the naked eye using a simple ultraviolet light on the silica membrane, and significant discrimination between the positive and negative samples could be easily and visually obtained. Besides, chitooligosaccharide-modified silica membrane allows the purification of nucleic acid in a totally aqueous system and enables in situ SEA. With the proposed integrated platform, 102-108 cfu/mL Vibrio parahaemolyticus could be successfully detected and excellent performance was also revealed for gram-positive pathogens. The detection limit of the method for artificially spiked oysters was 103 cfu/g and reached 100 cfu/g after 12 h enrichment. This proof-of-concept method could also be applied to a variety of nucleic acid amplification methods. We believe that the proposed silica membrane-based platform has great potential for the rapid and low-cost detection of nucleic acids especially in low-resource settings. Graphical abstract.

Lab in a Pasteur pipette: low-cost, rapid and visual detection of Bacillus cereu using denaturation bubble-mediated strand exchange amplification.

Driven by a bright prospect for rapid, portable and cost-effective point-of-care testing, an assembled Pasteur pipette device to integrate nucleic acid extraction, amplification and detection was developed to detect B. cereus in a sample-to-answer format. Denaturation Bubble-mediated Strand Exchange Amplification (SEA) was chosen to perform isothermal amplification because it requires only a pair of primers and one Bst DNA polymerase. The established SEA can detect as low as 1.0 × 10-13 M genomic DNA of B. cereus, which was comparable with the previously reported method for B. cereus detection. The assembled Pasteur pipette allows sample-to-answer diagnostic in a simple, low-cost, portable, and disposable format. The inherent function of Pasteur pipette enables direct liquid handling without the need of extra pipettes, syringes or pumps. Visual readout was achieved by using a pH sensitive dye, further simplifying result judgment process. The detection limit for B. cereus is 1.0 × 104 CFU/mL in pure cultures, while the detection limit in artificially contaminated milk is 1.0 × 105 CFU/mL without enrichment and 1.0 × 100 CFU/mL following 12 h enrichment. Considering that typical cell counts in food samples associated to food poisoning are 1.0 × 105 to 1.0 × 108 CFU per gram/milliliter B. cereus, our Pasteur pipette is enough sensitive for answer-to-sample diagnosis of B. cereus even directly from foods without enrichment. The whole diagnostic procedure could be completed within 50 min, dramatically decreasing the detection time. In a word, the assembled Pasteur pipette device, combined with a homemade metal bath, possesses great potential for sample-to-answer application in resource-limited settings.

Using health insurance reimbursement data to identify incident cancer cases.

OBJECTIVES: The objective of this study was to establish an optimal population-level follow-up strategy for identifying incident cancers using health insurance reimbursement data in rural China. STUDY DESIGN AND SETTING: We compared active follow-up and passive linkage with claims data for identification of incident cancer cases. Claims data were derived from the New Rural Cooperative Medical Scheme (NCMS). Follow-up data from subject enrollment to December 31, 2016, regarding 33,948 subjects in a large-scale randomized controlled trial were used in this study. RESULTS: The overall sensitivity of passive linkage with NCMS claims data was significantly higher than that of active follow-up (95.6% vs. 54.9%, P < 0.001). Of 12 cases missed by the NCMS data set, seven were treated on an outpatient basis and there were therefore no records in the NCMS system, and five were diagnosed at primary (township-level) health facilities and excluded from the quality control process. Of the 123 cases missed by active follow-up, 54 were reported as negative, 69 were reported as positive but had inaccurate information regarding the site of cancer, or exceeded the 6-month limitation from the date of diagnosis. CONCLUSION: Passive linkage with NCMS claims data is an efficient approach for identifying incident cancers in areas without cancer registries in rural China.

Estimation of Cost for Endoscopic Screening for Esophageal Cancer in a High-Risk Population in Rural China: Results from a Population-Level Randomized Controlled Trial.

BACKGROUND AND OBJECTIVE: Population-level endoscopic screening for esophageal cancer has been conducted in China for years. In this study, we aim to provide an updated and precise cost estimation for esophageal cancer screening based on a randomized controlled trial in a high-risk area in China. METHODS: We estimated the cost of esophageal cancer screening with chromoendoscopy using a micro-costing approach based on primary data of the ESECC (Endoscopic Screening for Esophageal Cancer in China) randomized controlled trial (NCT01688908) from a health sector perspective. Unit costs and quantities of resources were collected to obtain annual screening costs. The screening project was then theoretically expanded to a 10-year period to explore long-term trends of costs. Costs were adjusted to US dollars for the year 2018. RESULTS: In the ESECC trial, screening cost per endoscopy with a valid pathologic diagnosis was $196, accounting for 3.82% of the gross domestic product per capita in Hua County, and the costs for detecting one esophageal cancer and one early-stage esophageal cancer were $26,347 and $37,687, respectively. In conventional screening in which protocol-driven costs were excluded, costs as above were $134, $18,074, and $25,853. The cost for detecting one gastric cardia cancer or stomach cancer was nine times higher than detecting one esophageal cancer owing to low prevalences of the two cancers. In a simulated 10-year screening project, annual cost decreased notably over time. CONCLUSIONS: Despite the relatively low absolute cost, population-level endoscopic screening will still be a heavy burden on local government considering the socioeconomic conditions. Long-lasting programs would be less costly and population-level screening would make little sense in non-high-risk regions.

[Pollution Characteristic and Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Groundwater of Shen-Fu New City in the Hunhe River Basin].

To protect the safety of water used by the residents in Shen-Fu New City, which is undergoing the process of urbanization, 49 groundwater samples were collected along the Hunhe River Basin and 16 US EPA priority control polycyclic aromatic hydrocarbons (PAHs) were analyzed. The occurrence, distribution characteristics, sources, and potential health risk of drinking the groundwater were also assessed in this study. The results show that PAHs were detected in all samples. The concentration of PAHs ranges from 4.38 to 2005.02 ng·L-1, with an average value of (414.64±526.13) ng·L-1. Based on the comparison of the concentration level with that of other regions, the results in this study indicate a higher pollution level. The 3-4 ring PAHs are dominant; the average value was (190.93±238.96) ng·L-1 and (140.01±234.69) ng·L-1, respectively, accounting for 80% of the total PAHs. The distribution of PAHs in the groundwater is affected by the land use types. The concentration of PAHs is higher when the land use type is cultivated land, while it is lower when it is forest land. The source of PAHs was identified using Principal Component Analysis-Multiple Linear Regression (PCA-MLR). It was revealed that 36.26% of the PAHs are due to incomplete combustion of petroleum and gas, 32.72% are due to coal combustion, 28.17% originate from petroleum spills, and 2.87% are due to traffic emissions. The cancer risk levels releated to drinking the groundwater range from 5.55×10-10 to 5.65×10-6 and 13.60% of the values is in the range of 10-6-10-4. The levels are higher than the baseline of the acceptable risk, indicating the potential cancer risk. More attention should be paid to the quality of the groundwater.

[Sources and Risk Assessment of Polycyclic Aromatic Hydrocarbons from the Urbanization Process of Topsoil].

To study the effects of urbanization on concentration, sources, and health risks of polycyclic aromatic hydrocarbons (PAHs), 95 topsoil samples were collected from Liaoning Province. For this assessment, 21 PAHs were analyzed via gas chromatography-mass spectrometry and discussed. The results show the total concentrations of the 21 PAHs in background, Shen-Fu, Shen-Yang, and Fu-Shun were 1496.76 µg·kg-1, 3000.50 µg·kg-1, 8705.11 µg·kg-1, and 8178.90 µg·kg-1, respectively, which is positively correlated with the urbanization levels. Diagnostic ratios and PMF modal analysis indicate that the sources of the PAHs in soils were most likely coal combustion and traffic combustion (petroleum combustion). The main sources of PAHs in the four areas were petrochemical combustion (41.0%), coal combustion (64.4%), traffic combustion (67.5%), and traffic combustion (62.0%), that is, with the urbanization process, human activity (mainly traffic combustion) gradually become the major contributor of PAHs to the environment. Health risk assessment showed that the risk of cancer exposure through soil digestion and skin exposure was higher. There is a higher health risk from PAHs in urban soils, and the health risks associated with children and adolescents are greater than with other residents, requiring more attention.

Application and microbial preparation of D-valine.

D-Valine is an important organic chiral source and has extensive industrial application, which is used as intermediate for the synthesis of agricultural pesticides, semi-synthetic veterinary antibiotics and pharmaceutical drugs. Its derivatives have shown great activity in clinical use, such as penicillamine for the treatment of immune-deficiency diseases, and actinomycin D for antitumor therapy. Fluvalinate, a pyrethroid pesticide made from D-valine, is a broad-spectrum insecticide with low mammalian toxicity. Valnemulin, a semi-synthetic pleuromutilin derivative synthesized from D-valine, is an antibiotic for animals. Moreover, D-valine is also used in cell culture for selectively inhibiting fibroblasts proliferation. Due to its widespread application, D-valine is gaining more and more attention and some approaches for D-valine preparation have been investigated. In comparison with other approaches, microbial preparation of D-valine is more competitive and promising because of its high stereo selectivity, mild reaction conditions and environmental friendly process. So far, microbial preparation of D-valine can be mainly classified into three categories: microbial asymmetric degradation of DL-valine, microbial stereoselective hydrolysis of N-acyl-DL-valine by D-aminoacylase, and microbial specific hydrolysis of DL-5-isopropylhydantoin by D-hydantoinase coupled with D-carbamoylase. In this paper, the industrial application of D-valine and its microbial preparation are reviewed.

An improved chloroplast DNA extraction procedure for whole plastid genome sequencing.

BACKGROUND: Chloroplast genomes supply valuable genetic information for evolutionary and functional studies in plants. The past five years have witnessed a dramatic increase in the number of completely sequenced chloroplast genomes with the application of second-generation sequencing technology in plastid genome sequencing projects. However, cost-effective high-throughput chloroplast DNA (cpDNA) extraction becomes a major bottleneck restricting the application, as conventional methods are difficult to make a balance between the quality and yield of cpDNAs. METHODOLOGY/PRINCIPAL FINDINGS: We first tested two traditional methods to isolate cpDNA from the three species, Oryza brachyantha, Leersia japonica and Prinsepia utihis. Both of them failed to obtain properly defined cpDNA bands. However, we developed a simple but efficient method based on sucrose gradients and found that the modified protocol worked efficiently to isolate the cpDNA from the same three plant species. We sequenced the isolated DNA samples with Illumina (Solexa) sequencing technology to test cpDNA purity according to aligning sequence reads to the reference chloroplast genomes, showing that the reference genome was properly covered. We show that 40-50% cpDNA purity is achieved with our method. CONCLUSION: Here we provide an improved method used to isolate cpDNA from angiosperms. The Illumina sequencing results suggest that the isolated cpDNA has reached enough yield and sufficient purity to perform subsequent genome assembly. The cpDNA isolation protocol thus will be widely applicable to the plant chloroplast genome sequencing projects.

[Clinical value of CEA and CYFRA21-1 as an assessment indicator of therapeutic efficacy in advanced non-small cell lung cancer patients].

OBJECTIVE: To investigate the value of carcinoembryonic antigen (CEA) or cytokeratin 19 fragment (CYFRA21-1) as an assessment indicator of therapeutic efficacy in advanced non-small cell lung cancer (NSCLC) patients. METHODS: 228 cases of advanced NSCLC with chemotherapy were enrolled into this retrospective study. The serum CEA or CYFRA21-1 levels of all patients were above the cut-off limit before treatment. The relationship between changes of tumor markers (TMs) and imaging therapeutic efficacy or progression-free survival (PFS) was analyzed, and the value of TMs in therapeutic efficacy assessment was evaluated. RESULTS: According to RECIST criteria, partial response (PR) occurred in 40 cases, stable disease (SD) in 151 and PD (progressive disease) in 37. The cut-off values of the changes of TMs between pre- and post-treatment were determined according to the above mentioned criteria. The CEA down (D), stable (S), above (A) groups were 90, 49 and 66 cases, respectively. CYFRA21-1 down (D), stable (S), above (A) groups were 84, 26 and 37 cases, respectively. PR groups were 68.4% and 88.9% in CEA and cyfra21-1 down groups, respectively, 7.9% and 5.6% in the above groups, respectively. PD groups were 59.4% and 76.2% in CEA and CYFRA21-1 above groups, respectively. No PD cases were in the down groups. The changes of TMs in SD group were between them. Statistically significant correlations were observed between changes of TMs and imaging therapeutic efficacy (r(CEA) = 0.45, P = 0.00; r(CYFRA21-1) = 0.44, P = 0.00). PFS among different TMs groups were significantly different (all P < 0.05), which can be used to further distinguish the prognosis among SD subgroups. CONCLUSION: Changes of TMs can be used to predict the imaging therapeutic effect and PFS of the patients, and if the SD group is divided into subgroups according to different therapeutic efficacy and prognosis, it may help the patients to receive individualized treatment.

Molecular fiber sensors based on surface enhanced Raman scattering (SERS).

Molecular sensors based on surface enhanced Raman scattering (SERS) and optical fibers have been widely used in biological, environmental and chemical detection procedures due to their unique advantages, such as molecular specificity, high sensitivity and flexibility. In this paper, we review the development and highlight some of the important milestones of SERS fiber sensor development with emphasis on recent work to improve the sensitivity of the fiber sensors. In particular in the area to increase the sensitivity, we've reviewed various methods of sample preparation as well as different fiber SERS sensors. One way is to strengthen the field enhancement around the surface of the probe tip and the other is to increase the number of the interacting particles during the SERS process. These techniques are known as the double substrate "sandwich" structure (DSSS) and the liquid core photonic crystal fiber (LCPCF), and in both cases the sensitivities are significantly improved. These fiber sensors were tested with Rhodamine 6G, human insulin and tryptophan and showed excellent performance.