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The Ångström–Prescott formula is commonly used in climatological calculation methods of solar radiation simulation. Aiming at the characteristics of a vast area, few meteorological stations, and uneven distribution in the tropical regions of China, in order to obtain the optimal parameters of the global solar radiation calculation model, this study proposes a suitable monthly global solar radiation model based on the single-station approach and the between-groups linkage of the A–P model, which utilizes monthly measured meteorological data from 80 meteorological stations spanning the period from 1996 to 2016 in the tropical zone of China, considering the similarity in changes of monthly sunshine percentage between stations. The applicability and accuracy of the correction parameters (a and b coefficients) were tested and evaluated, and then the modified parameters were extended to conventional meteorological stations through Thiessen polygons. Finally, the spatial distribution of solar radiation in the tropical region of China was simulated by kriging, IDW, and spline interpolation techniques. The results show the following: (1) The single-station model exhibited the highest accuracy in simulating the average annual global solar radiation, followed by the model based on the between-groups linkage. After optimizing the a and b coefficients, the simulation accuracy of the average annual global solar radiation increased by 5.3%, 8.1%, and 4.4% for the whole year, dry season, and wet season, respectively. (2) Through cross-validation, the most suitable spatial interpolation methods for the whole year, dry season, and wet season in the tropical zone of China were IDW, Kriging, and Spline, respectively. This research has positive implications for improving the accuracy of solar radiation prediction and guiding regional agricultural production. [ABSTRACT FROM AUTHOR]

The NAC gene family has transcription factors specific to plants, which are involved in development and stress response and adaptation. In this study, ZmNAC89, an NAC gene in maize that plays a role in saline–alkaline tolerance, was isolated and characterized. ZmNAC89 was localized in the nucleus and had transcriptional activation activity during in vitro experiments. The expression of ZmNAC89 was strongly upregulated under saline–alkaline, drought and ABA treatments. Overexpression of the ZmNAC89 gene in transgenic Arabidopsis and maize enhanced salt tolerance at the seedling stage. Differentially expressed genes (DEGs) were then confirmed via RNA-sequencing analysis with the transgenic maize line. GO analyses showed that oxidation–reduction process-regulated genes were involved in ZmNAC89-mediated salt–alkaline stress. ZmNAC89 may regulate maize saline–alkali tolerance through the REDOX pathway and ABA signal transduction pathway. From 140 inbred maize lines, 20 haplotypes and 16 SNPs were found in the coding region of the ZmNAC89 gene, including the excellent haplotype HAP20. These results contribute to a better understanding of the response mechanism of maize to salt–alkali stress and marker-assisted selection during maize breeding. [ABSTRACT FROM AUTHOR]

The growth simulation of urban underground space (UUS) under the consideration of ecological constraints can effectively reveal the characteristics and trends of UUS changes, and provide a basis for planning the construction of sustainable and livable ecological cities. Therefore, this study considers urban ecological space as a constraint mechanism for UUS development and conducts a simulation study of the dynamic and complex UUS growth process, with a view toward guiding UUS planning under a long-term overall vision. In this study, a patch-based cellular automaton (CA) model is constructed to simulate the dynamic and complex growth process of UUS, subject to the ecological constraints generated by the agent-based land allocation optimization model. The spatial drivers of UUS growth simulation are determined based on the Random Forest (RF) algorithm. The results of the research case in Tianfu New District, Chengdu City, demonstrate that UUS expansion with ecological constraints exhibits sustainable characteristics. However, the growth rate of the UUS development scale is significantly lower when ecological constraints are present compared to when they are not. This study's results contribute to urban management by finding a balance between UUS development and ecological space conservation, and providing theoretical support for rational UUS planning and decision making in the construction of low-carbon cities. [ABSTRACT FROM AUTHOR]

Lung adenocarcinoma (LUAD) is a prevalent type of thoracic cancer with a poor prognosis and high mortality rate. However, the exact pathogenesis of this cancer is still not fully understood. One potential factor that can contribute to the development of lung adenocarcinoma is DNA methylation, which can cause changes in chromosome structure and potentially lead to the formation of tumors. The baculoviral IAP repeat containing the 5 (BIRC5) gene encodes the Survivin protein, which is a multifunctional gene involved in cell proliferation, migration, and invasion of tumor cells. This gene is elevated in various solid tumors, but its specific role and mechanism in lung adenocarcinoma are not well-known. To identify the potential biomarkers associated with lung adenocarcinoma, we screened the methylation-regulated differentially expressed genes (MeDEGs) of LUAD via bioinformatics analysis. Gene ontology (GO) process and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were applied to investigate the biological function and pathway of MeDEGs. A protein–protein interaction (PPI) network was employed to explore the key module and screen hub genes. We screened out eight hub genes whose products are aberrantly expressed, and whose DNA methylation modification level is significantly changed in lung adenocarcinoma. BIRC5 is a bona fide marker which was remarkably up-regulated in tumor tissues. Flow cytometry analysis, lactate dehydrogenase release (LDH) assay and Micro-PET imaging were performed in A549 cells and a mouse xenograft tumor to explore the function of BIRC5 in cell death of lung adenocarcinoma. We found that BIRC5 was up-regulated and related to a high mortality rate in lung adenocarcinoma patients. Mechanically, the knockdown of BIRC5 inhibited the proliferation of A549 cells and induced pyroptosis via caspase3/GSDME signaling. Our findings have unraveled that BIRC5 holds promise as a novel biomarker and therapeutic target for lung adenocarcinoma. Additionally, we have discovered a novel pathway in which BIRC5 inhibition can induce pyroptosis through the caspase3-GSDME pathway in lung adenocarcinoma cells. [ABSTRACT FROM AUTHOR]

Diabetic cardiomyopathy (DCM) is widely recognized as a major contributing factor to the development of heart failure in patients with diabetes. Previous studies have demonstrated the potential benefits of traditional herbal medicine for alleviating the symptoms of cardiomyopathy. We have chemically designed and synthesized a novel compound called aloe-emodin derivative (AED), which belongs to the aloe-emodin (AE) family of compounds. AED was formed by covalent binding of monomethyl succinate to the anthraquinone mother nucleus of AE using chemical synthesis techniques. The purpose of this study was to investigate the effects and mechanisms of AED in treating DCM. We induced type 2 diabetes in Sprague–Dawley (SD) rats by administering a high-fat diet and streptozotocin (STZ) injections. The rats were randomly divided into six groups: control, DCM, AED low concentration (50 mg/kg/day), AED high concentration (100 mg/kg/day), AE (100 mg/kg/day), and positive control (glyburide, 2 mg/kg/day) groups. There were eight rats in each group. The rats that attained fasting blood glucose of ˃16.7 mmol/L were considered successful models. We observed significant improvements in cardiac function in the DCM rats with both AED and AE following four weeks of intragastric treatment. However, AED had a more pronounced therapeutic effect on DCM compared to AE. AED exhibited an inhibitory effect on the inflammatory response in the hearts of DCM rats and high-glucose-treated H9C2 cells by suppressing the pyroptosis pathway mediated by the nucleotide-binding oligomerization domain (NOD)-like receptor pyrin domain 3 (NLRP3) inflammasome. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of differentially expressed genes showed a significant enrichment in the NOD-like receptor signaling pathway compared to the high-glucose group. Furthermore, overexpression of NLRP3 effectively reversed the anti-pyroptosis effects of AED in high-glucose-treated H9C2 cells. This study is the first to demonstrate that AED possesses the ability to inhibit myocardial pyroptosis in DCM. Targeting the pyroptosis pathway mediated by the NLRP3 inflammasome could provide a promising therapeutic strategy to enhance our understanding and treatment of DCM. [ABSTRACT FROM AUTHOR]

This study aimed to explore the pharmacokinetics (PK) and safety of oral (PO) and intravenous (IV) lefamulin in healthy Chinese subjects and to evaluate the efficacy of the intravenous administration regimen using pharmacokinetic/pharmacodynamic (PK/PD) analysis. This study was a randomized, open-label, single- and multiple-dose, intravenous and oral administration study. PK parameters were calculated, and the probability of target attainment (PTA) and the cumulative fraction of response (CFR) after IV administration of lefamulin 150 mg 1 h q12 h were analyzed with Monte Carlo simulations. Lefamulin exhibited extensive distribution. The mean steady-state AUC0–24 h of 150 mg lefamulin IV and 600 mg lefamulin PO were 10.03 and 13.96 μg·h/mL, respectively. For Streptococcus pneumoniae and Staphylococcus aureus, based on the free-drug AUC over MIC ratio (fAUC/MIC) target of 1-log10 cfu reduction, the PK/PD breakpoints were 0.25 and 0.125 mg/L, respectively. The CFR was over 90% for both types of strains with 95% protein binding rate, suggesting that the regimen was microbiologically effective. Lefamulin was safe and well-tolerated. The PK of lefamulin in healthy Chinese subjects were consistent with that in foreign countries. Lefamulin demonstrated the microbiological effectiveness against Streptococcus pneumoniae and Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

This paper generalizes the structural Markov properties for undirected decomposable graphs to arbitrary ones. This helps us to exploit the conditional independence properties of joint prior laws to analyze and compare multiple graphical structures, while being able to take advantage of the common conditional independence constraints. This work provides a theoretical support for full Bayesian posterior updating about the structure of a graph using data from a certain distribution. We further investigate the ratio of graph law so as to simplify the acceptance probability of the Metropolis–Hastings sampling algorithms. [ABSTRACT FROM AUTHOR]

Objective: Anxiety symptoms are persistent in Parkinson's disease (PD), but the underlying neural substrates are still unclear. In the current study, we aimed to explore the underlying neural mechanisms in PD patients with anxiety symptoms. Methods: 42 PD-A patients, 41 PD patients without anxiety symptoms (PD-NA), and 40 healthy controls (HCs) were recruited in the present study. All the subjects performed 3.0T fMRI scans. The fractional amplitude of low-frequency fluctuation (fALFF) analysis was used to investigate the alterations in neural activity among the three groups. A Pearson correlation analysis was performed between the altered fALFF value of the PD-A group and anxiety scores. Results: Compared with HCs, PD-A patients had higher fALFF values in the left cerebellum, cerebellum posterior lobe, bilateral temporal cortex, and brainstem and lower fALFF values in the bilateral inferior gyrus, bilateral basal ganglia areas, and left inferior parietal lobule. Moreover, between the two PD groups, PD-A patients showed higher fALFF values in the right precuneus and lower fALFF values in the bilateral inferior gyrus, bilateral basal ganglia areas, left inferior parietal lobule, and left occipital lobe. Furthermore, Pearson's correlation analysis demonstrated that the right precuneus and left caudate were correlated with the Hamilton Anxiety Rating Scale scores. Conclusion: Our study found that anxiety symptoms in PD patients may be related to alterations of neurological activities in multiple brain regions. Furthermore, these may be critical radiological biomarkers for PD-A patients. Therefore, these findings can improve our understanding of the pathophysiological mechanisms underlying PD-A. [ABSTRACT FROM AUTHOR]

This paper aims to find out the optimal mileage of battery electric vehicles (BEVs) by considering the trade-off between range anxiety and charging times, since frequent charging is a customary way to ease range anxiety for BEV drivers in practice, but declines the life cycle of battery and increases the charging cost. We propose a power function to measure the range anxiety and then solve two types of optimal mileages. The results show that the increment of BEVs' cruising range increases the optimal absolute mileage but decreases the optimal relative mileage, while the improvement of the driver's tolerance to range anxiety increases both. It is concluded that improving the driver's tolerance, such as by expanding charging infrastructures and raising drivers' practical experience with BEVs, is more effective than the increment of BEVs' cruising range. The findings help to understand the optimal mileage of EVs and provide recommendations on the design of BEVs' cruising range. [ABSTRACT FROM AUTHOR]

Variations of precipitation type can exert substantial impacts on hydrological processes, yet few studies have quantified the impacts of precipitation type variations on runoff changes in high−altitude regions. In this study, we attempted to examine the potential impacts of precipitation type variations induced by the warming climate on the runoff changes of the source regions of the Yangtze River and Yellow River basins from 1979 to 2018, where the mean elevation is over 4000 m. A modified precipitation type identification method using the wet-bulb temperature, and a runoff change attribution method based on a modified Budyko framework has been applied. Results showed that fluctuations of precipitation contributed to the majority of the runoff variations in the source regions of the Yangtze River basin, which accounted for 51.64%. However, the changes of characteristic parameter n, which indicates the impacts of the underlying surface, explained 56.22% of the runoff changes in the source regions of the Yellow River. It was shown that the trend of shifting from snowfall to rainfall due to a warming climate could result in runoff decreasing, which contributed to 24.06% and 11.29% of the runoff changes in the two source regions, comparatively. [ABSTRACT FROM AUTHOR]

The 2-m temperature is one of the important meteorological elements, and improving the accuracy of medium- and long-term forecasts of the 2-m temperature is important. The similarity forecasting method is widely used as a calibration technique in the statistical postprocessing of numerical weather prediction (NWP). In this study, the analogue ensemble averaging method is used to correct the deterministic forecast of the 2-m temperature with a forecast lead time from 180 h to 348 h using the CMA-GEPS model. The bias, mean absolute error (MAE), and root mean square error (RMSE) are used as the evaluation metrics. In comparison with NWP, the systematic error of the model for 2-m temperature is effectively reduced during each forecast period when using the analogue ensemble averaging method. In addition, the differences in forecast errors between regions are reduced, and the accuracy of 2-m temperature forecasts over complex terrain, especially in Southwest China, Northwest China, and North China, is improved using this method. In the future, there is certainly potential to apply the analogue ensemble averaging method to the bias correction of medium- and long-term forecasts of more meteorological elements. [ABSTRACT FROM AUTHOR]

Idiopathic pulmonary fibrosis (IPF) is an age-related interstitial lung disease with a high incidence in the elderly. Although many reports have shown that senescence can initiate pulmonary fibrosis, the relationship between aging and pulmonary fibrosis has not been explained systematically. In our study, young and old rats were intratracheally instilled with bleomycin (1 mg/kg), and the basic pathological indexes were determined using a commercial kit, hematoxylin, and eosin (H&E) and Masson's Trichrome staining, immunohistochemistry, immunohistofluorescence, and q-PCR. Then, the lung tissues of rats were sequenced by next-generation sequencing for transcriptome analysis. Bioinformatics was performed to analyze the possible differences in the mechanism of pulmonary fibrosis between aged and young rats. Finally, the related cytokines were determined by q-PCR and ELISA. The results indicate that pulmonary fibrosis in old rats is more serious than that in young rats under the same conditions. Additionally, transcriptomic and bioinformatics analysis with experimental validation indicate that the differences in pulmonary fibrosis between old and young rats are mainly related to the differential expression of cytokines, extracellular matrix (ECM), and other important signaling pathways. In conclusion, aging mainly affects pulmonary fibrosis through the ECM–receptor interaction, immune response, and chemokines. [ABSTRACT FROM AUTHOR]

Tourism is emerging as an important contributor sector to carbon emissions. As inbound tourism is the main component of tourism activities, measuring and evaluating the carbon footprint of inbound tourism can help achieve low-carbon development of the global tourism industry. Based on the carbon footprint theory, this study describes the distribution and transfer path of China's inbound tourism carbon footprint by using the China multi regional input-output model embedded in the inbound tourism satellite account. The results reveal that embodied carbon emissions (ECE) of inbound tourism is higher than direct carbon emissions, and carbon emissions intensity is close to the average economic. Therefore, it is difficult for inbound tourism to achieve the dual goals of stimulating economic growth and emission mitigation. The ECE of inbound tourism has obvious inter-provincial transfer characteristics. Inner Mongolia and Guangdong are the largest provinces with net outflows/inflows of ECE, with net outflows of 1.47 million tons and inflows of 2.66 million tons. Besides, the ECE mainly flows from the northeast and northwest regions to the southern and eastern regions. From the perspective of industry transfer, 72.2% of ECE of inbound tourism comes from the power sector. [ABSTRACT FROM AUTHOR]

China and G7 countries contribute 70% global GDP and 55% global carbon emissions. The carbon leakage between China and G7 is a crucial issue in achieving the synergetic emission abatement globally. The motivation of this study is to evaluate the embodied carbon transfer between China and G7 in the trade between 2000 and 2014, and investigate the driving factors that impact the embodied carbon trend. A multiregional input–output (MRIO) model based on the WIOD database is constructed, and a structural decomposition analysis (SDA) is employed. The results indicate that China plays the role of net exporter of embodied carbon in trade with G7, which mainly flows to the US (5825.67 Mt), Japan (3170.36 Mt) and Germany (1409.93 Mt). However, China's embodied carbon exports to the G7 show an inverted U-shaped trend with a turning point after financial crisis, while the G7's embodied carbon exports to China continue to rise. The conclusion is that to achieve the climate goal of carbon neutrality, it is not enough to rely solely on the low-carbon transition on the production side, the demand side should also be adjusted. [ABSTRACT FROM AUTHOR]

Betel palms and mango plantations are two crucial commercial crops in tropical agricultural areas. Accurate spatial distributions of these two crops are essential in tropical agricultural regional planning and management. However, the characteristics of small patches, scattering, and perennation make it challenging to map betel palms and mango plantations in complex tropical agricultural regions. Furthermore, the excessive features of very-high-resolution (VHR) imaging might lead to a reduction in classification accuracy and an increase in computation times. To address these challenges, we selected five feature selection (FS) methods (random forest means a decrease in accuracy (RFMDA), ReliefF, random forest-recursive feature elimination (RFE), aggregated boosted tree (ABT), and logistic regression (LR)) and four machine learning algorithms (random forest (RF), support vector machine (SVM), classification and regression tree (CART), and adaptive boosting (AdaBoost)). Then, the optimal combinations of FS and machine learning algorithms suited for object-oriented classification of betel palms and mango plantations were explored using VHR Gaofen-2 imagery. In terms of overall accuracy, all optimal classification schemes exceeded 80%, and the classifiers using selected features increased the overall accuracy between 1% and 4% compared with classification without FS methods. Specifically, LR was appropriate to RF and SVM classifiers, which produced the highest classification accuracy (89.1% and 89.88% for RF and SVM, respectively). In contrast, ABT and ReliefF were found to be suitable FS methods for CART and AdaBoost classifiers, respectively. Overall, all four optimal combinations of FS methods and classifiers could precisely recognize mango plantations, whereas betel palms were best depicted by using the RF-LR method with 26 features. The results indicated that combination of feature selection and machine learning algorithms contributed to the object-oriented classification of complex tropical crops using Gaofen-2 imagery, which provide a useful methodological reference for precisely recognizing small tropical agricultural patterns. [ABSTRACT FROM AUTHOR]

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure. [ABSTRACT FROM AUTHOR]

In order to improve the general problem of irregular coating morphology and low mechanical strength of the coating layer in existing coating desensitization technology, nano-cyclotrimethylene trinitramine/melamine-urea-formaldehyde (RDX/MUF) composite energetic microspheres were prepared by an improved emulsion polymerization, taking the MUF as the binder and RDX as the main explosive. In order to judge whether RDX/MUF possessed good stability, the combination of differential scanning calorimetry (DSC) and molecular dynamics (MD) simulation was used to determine the level of binding binding energy between urea-formaldehyde resin binder (UF) and RDX. In addition, to investigate the optimal reaction temperature for the preparation of MUF/RDX, the binding energy between UF and RDX at different temperatures was simulated. And then the morphology and thermal properties of the as-prepared composite energetic microspheres were analyzed by scanning electron microscopy (SEM) and DSC, the impact sensitivity and friction sensitivity of the resultant samples were tested as well. Moreover, RDX/MUF with the same MUF content was prepared by physical mixing for comparative analysis. MD simulation demonstrated that UF and RDX possessed good binding ability at 298 K. The DSC method indicatec that UF and RDX had good compatibility, and the comprehensive performance of RDX after coating was not significantly deteriorated; The optimal binding temperature between UF and RDX was 60~70 °C which is consistent with the experimental results. The experimental results showed that the optimum process conditions for the preparation of RDX/MUF could be listed as follows: the temperature for preparing RDX/MUF composite energetic microspheres by the improved emulsion polymerization was 70 °C the optimal pH value of the urea-formaldehyde resin prepolymer solution was 3, and the optimal melamine-urea molar ratio was 0.4. [ABSTRACT FROM AUTHOR]

In this work, a novel strategy was developed to fabricate prevascularized cell-layer blood vessels in thick tissues and small-diameter blood vessel substitutes using three-dimensional (3D) bioprinting technology. These thick vascularized tissues were comprised of cells, a decellularized extracellular matrix (dECM), and a vasculature of multilevel sizes and multibranch architectures. Pluronic F127 (PF 127) was used as a sacrificial material for the formation of the vasculature through a multi-nozzle 3D bioprinting system. After printing, Pluronic F127 was removed to obtain multilevel hollow channels for the attachment of human umbilical vein endothelial cells (HUVECs). To reconstruct functional small-diameter blood vessel substitutes, a supporting scaffold (SE1700) with a double-layer circular structure was first bioprinted. Human aortic vascular smooth muscle cells (HA-VSMCs), HUVECs, and human dermal fibroblasts–neonatal (HDF-n) were separately used to form the media, intima, and adventitia through perfusion into the corresponding location of the supporting scaffold. In particular, the dECM was used as the matrix of the small-diameter blood vessel substitutes. After culture in vitro for 48 h, fluorescent images revealed that cells maintained their viability and that the samples maintained structural integrity. In addition, we analyzed the mechanical properties of the printed scaffold and found that its elastic modulus approximated that of the natural aorta. These findings demonstrate the feasibility of fabricating different kinds of vessels to imitate the structure and function of the human vascular system using 3D bioprinting technology. [ABSTRACT FROM AUTHOR]

A light-up fluorescent probe for the detection of adenosine was constructed with an AIE (aggregation-induced emission) molecule and a DNA aptamer. The AIE molecule was used as a signal generator, and the DNA aptamer was used as a recognition element for adenosine. The emission of the AIE molecule was due to its intramolecular rotation restriction induced by the aptamer upon binding of adenosine. The optimal component ratio of the probe was AIE molecule / DNA aptamer = 100 (μM/μM). The calibration curve of adenosine detection showed a linear range of 10 pM to 0.5 μM with an R² of 0.996, and the detection limit of the probe was 10 pM. The probe exhibited a good selectivity to adenosine against its analogs (uridine, guanosine, and cytidine). The probe was used to detect adenosine in urine samples, a recovery from 86.8% to 90.0% for the spiked concentrations of adenosine (0.01, 0.05, 0.1 μM). The relative standard deviation from 1.2% to 2.0% was obtained. The intra-day and inter-day tests also showed good precisions, with measurement RSD values of 2.3% and 2.1%, respectively., Competing Interests: The authors declare no conflict of interest.

The use of α-glucosidase inhibitors is considered to be an effective strategy in the treatment of diabetes. Using a bioassay-guided fractionation technique, five Bacillus stearothermophilus α-glucosidase inhibitors were isolated from the flowers of Musa spp. (Baxijiao). Using NMR spectroscopy analysis they were identified as vanillic acid (1), ferulic acid (2), β-sitosterol (3), daucosterol (4) and 9-(4'-hydroxyphenyl)-2-methoxyphenalen-1-one (5). The half maximal inhibitory concentration (IC50) values of compounds 1-5 were 2004.58, 1258.35, 283.67, 247.35 and 3.86 mg/L, respectively. Compared to a known α-glucosidase inhibitor (acarbose, IC50=999.31 mg/L), compounds 3, 4 and 5 showed a strong α-glucosidase inhibitory effect. A Lineweaver-Burk plot indicated that compound 5 is a mixed-competitive inhibitor, while compounds 3 and 4 are competitive inhibitors. The inhibition constants (Ki) of compounds 3, 4 and 5 were 20.09, 2.34 and 4.40 mg/L, respectively. Taken together, these data show that the compounds 3, 4 and 5 are potent α-glucosidase inhibitors.