Assessment of battery utilization and energy consumption in the large-scale development of urban electric vehicles.

Electrifying transportation in the form of the large-scale development of electric vehicles (EVs) plays a pivotal role in reducing urban atmospheric pollution and alleviating fossil fuel dependence. However, the rising scale of EV deployment is exposing problems that were previously hidden in small-scale EV applications, and the lack of large-scale EV operating data deters relevant explorations. Here, we report several issues related to the battery utilization and energy consumption of urban-scale EVs by connecting three unique datasets of real-world operating states of over 3 million Chinese EVs, operational data, and vehicle feature data. Meanwhile, by incorporating climatic data and EV data outside China, we extend our models to several metropolitan areas worldwide. We find that blindly increasing the battery energy of urban EVs could be detrimental to sustainable development. The impact of changes in the energy consumption of EVs would be exacerbated in large-scale EV utilization, especially during seasonal shifts. For instance, even with a constant monthly driving demand, the average energy consumption of Beijing light-duty EVs would change by up to 21% during winter-spring shifts. Our results may also prove useful for research on battery resources, urban power supply, environmental impacts, and policymaking.

Detection of Circulating Tumor Cells Using a Novel Immunomagnetic Bead Method in Lung Cancer Patients.

BACKGROUND: Circulating tumor cells (CTCs) are detectable in peripheral blood of metastatic lung cancer patients. In this article, we evaluate a new CTC separation method based on a combination of anti-EpCAM and immunomagnetic beads with the aim to detect CTCs more conveniently and specifically. METHODS: Lung cancer cells were magnetically labeled by anti-EpCAM magnetic beads, and subsequently captured by magnetic separation using our novel device. Isolated lung cancer cells were identified by pathomorphological by hematoxylin-eosin staining protocol. The system was used to detect CTCs in 2 ml blood. Blood samples of healthy donors spiked with lung cancer cell line A549 cells were used to determine the sensitivity and specificity of the method. Prevalence of CTCs was examined in samples from 56 patients with lung cancer. RESULTS: Regression analysis of number of recovered versus spiked A549 cells yielded a coefficient of determination of R(2) = 0.996 (P < 0.001). The average recovery was 68% or more at each spiking level. The coefficient of variation increased as the number of spiked cells decreased, ranging from 6.4% (1,000-cell spike) to 18.4% (50-cell spike). Forty-nine of the fifty-six patients (87.5%) were found to have CTCs in peripheral blood. None of the 2 ml peripheral blood samples of the 20 healthy subjects analyzed were found to have CTCs. CONCLUSIONS: This novel turbulence device provides a new tool allowing for feasible and specific detection of CTCs in lung cancer patients. It is likely clinically useful in diagnosis and monitoring of lung cancer and may have a role in clinical decision making.

Economic and environmental benefits of automated electric vehicle ride-hailing services in New York City.

A precise, scalable, and computationally efficient mathematical framework is proposed for region-wide autonomous electric vehicle (AEV) fleet management, sizing and infrastructure planning for urban ride-hailing services. A comprehensive techno-economic analysis in New York City is conducted not only to calculate the societal costs but also to quantify the environmental and health benefits resulting from reduced emissions. The results reveal that strategic fleet management can reduce fleet size and unnecessary cruising mileage by up to 40% and 70%, respectively. This alleviates traffic congestion, saves travel time, and further reduces fleet sizes. Besides, neither large-battery-size AEVs nor high-power charging infrastructure is necessary to achieve efficient service. This effectively alleviates financial and operational burdens on fleet operators and power systems. Moreover, the reduced travel time and emissions resulting from efficient fleet autonomy create an economic value that exceeds the total capital investment and operational costs of fleet services.

[Differential invasion and metastasis capacities of methotrexate enantiomer-resistant A549 cell lines].

OBJECTIVE: To study the differential in vitro motor and invasion capacities of methotrexate (MTX) enantiomer-resistant tumor cells. METHODS: The incremental concentrations and successive low-dose induction were employed to acquire the cell series resistant to 15 µmol/L MTX enantiomer, namely L-(+)-MTX/A549 and D-(-)-MTX/A549. Their drug-resistant indices were determined by MTT assay and their migration capacities by wound healing assay. Double soft-agar clone formation was used to detect the colony efficiency and size. And Transwell was employed to detect the in vitro movement and invasion capacity of three cell types. RESULTS: The resistance indices of L-(+)-MTX/A549 and D-(-)-MTX/A549 were (6.1 ± 1.0) and (20.3 ± 1.8) respectively. At 72 hours after wound healing assay, the number of L-(+)-MTX/A549 entering scratch zone was fewer than that of D-(-)-MTX/A549; The numbers of colony formation in D-(-)-MTX/A549, L-(+)-MTX/A549 and parental cells were (50 ± 7), (44 ± 6), (52 ± 7) and the rates of colony formation (1.68% ± 0.23%), (1.49% ± 0.18%), (1.73% ± 0.23%) respectively. And there was no significant significance among three groups (P > 0.05). But the size of D-(-)-MTX/A549 was larger than that of L-(+)-MTX/A549. Transwell detected infiltration and invasion through artificial basement membrane Matrigel. The numbers of D-(-)-MTX/A549, L-(+)-MTX/A549 and parent cells were (267 ± 30), (106 ± 16) and (134 ± 16) respectively. The data were significant between D-(-)-MTX/A549 cells and L-(+)-MTX/A549 or parent cells (P < 0.05) but not significant between L-(+)-MTX/A549 and parent cells (P > 0.05). CONCLUSION: The D-(-)-MTX-induced NSCLC A549 cells have greater motor and invasion capacities than those of L-(+)-MTX-induced ones. It suggests that MTX enantiomer has different capacities of tumor invasion and metastasis after acquiring resistance.

[Differential gene expression of folylpolyglutamate synthetase in cytoplasm and mitochondria in acquired methotrexate enantiomers resistant to lung cancer A549 cell lines].

OBJECTIVE: To investigate the relationship between the resistance of methotrexate (MTX) enantiomer and the gene expression levels of folylpolyglutamate synthetase (FPGS). METHODS: The cell lines of MTX enantiomer resistance from 15 - 55 µmol/L were obtained when the A549 cell lines were exposed intermittently and progressively to an incremental dose of each MTX enantiomer. The resistant index of MTX resistance cell lines were detected by MTT. The gene expressions of FPGS in cytoplasm and mitochondria were detected by real-time quantitative polymerase chain reaction (PCR). RESULTS: The resistance indice of D-(-)-MTX resistant cell lines were higher than those of L-(+)-MTX resistant cells (32.7 ± 9.3 vs 11.5 ± 2.9, P < 0.05). The resistant indice of L-(+)-MTX/A549 were from 5 to 15, which mean the middle resistance. The resistant indice of D-(-)-MTX/A549 were more than 15, which mean the severe resistance. The expression of mFPGS had difference between resistant cell lines of L-(+) and D-(-)-MTX except at 15 µmol/L MTX (at 25 µmol/L, 1.3 ± 0.7 vs. 2.3 ± 0.9; at 35 µmol/L, 1.1 ± 0.9 vs. 2.6 ± 0.3; at 45 µmol/L, 1.0 ± 1.0 vs. 1.4 ± 0.8; at 55 µmol/L, 0.2 ± 0.1 vs. 1.0 ± 0.2; all P < 0.05). The expressions of cFPGS had no difference between resistant cell lines of L-(+) and D-(-)-MTX at 15 µmol/L MTX, while at 25 - 55 µmol/L, the cFPGS levels and resistance indice of D-(-)-MTX/A549 resistant cell lines showed a highly negative correlation (r = -0.95, P < 0.05). CONCLUSION: There may be a different mechanism between the first time treatment with 15 µmol/L dosage and the continual treatment with more than 25 µmol/L dosage in A549 cell lines. There had higher resistant index in D-(-)-MTX/A549 cell line than in L-(+)-MTX/A549 cell line. The results indicated that the difference in chirality should be considered in clinical treatment with MTX.

Optimizing and evaluating PCR-based pooled screening during COVID-19 pandemics.

Population screening played a substantial role in safely reopening the economy and avoiding new outbreaks of COVID-19. PCR-based pooled screening makes it possible to test the population with limited resources by pooling multiple individual samples. Our study compared different population-wide screening methods as transmission-mitigating interventions, including pooled PCR, individual PCR, and antigen screening. Incorporating testing-isolation process and individual-level viral load trajectories into an epidemic model, we further studied the impacts of testing-isolation on test sensitivities. Results show that the testing-isolation process could maintain a stable test sensitivity during the outbreak by removing most infected individuals, especially during the epidemic decline. Moreover, we compared the efficiency, accuracy, and cost of different screening methods during the pandemic. Our results show that PCR-based pooled screening is cost-effective in reversing the pandemic at low prevalence. When the prevalence is high, PCR-based pooled screening may not stop the outbreak. In contrast, antigen screening with sufficient frequency could reverse the epidemic, despite the high cost and the large numbers of false positives in the screening process.

High-performance capillary electrophoretic method for the quantification of global DNA methylation: application to methotrexate-resistant cells.

Global DNA hypomethylation in tumor tissue is a common characteristic in a variety of malignancies such as breast, colon, oral, lung, and blood cancers. A rapid and sensitive method has been developed for the determination of global DNA methylation in cells. Five substances--2'-deoxycytidine (dC), 5-methyl 2'-deoxycytidine (mdC), 2'-deoxyadenosine (dA), 2'-deoxythymidine (dT), and 2'-deoxyguanosine (dG)--were completely separated by high-performance capillary electrophoresis in 10 min. Intraday coefficient of variation was less than 1%, and interday coefficient of variation was less than 2%. The minimal detection limit was 1 microM. Acquired drug resistance to methotrexate (MTX) is one of the most serious problems in cancer chemotherapy. Under optimal conditions, we analyzed global DNA methylation levels in A549 and A549/MTX cells, and only 10(5) cells are needed to obtain reliable results. The percentage of 5-methyl-2'-deoxycytidine (5-mC) was 4.80+/-0.52% in A549 cells, and this decreased to 4.20+/-0.44% in A549/MTX cells. It was considered as statistically significant. This demonstrated that the mechanisms of acquired drug resistance to MTX might be concerned with DNA methylation.

[Chiral selectivity in differentiation of lung cancer A549 cell to vascular endothelial cells after drug resistance induced by D-or L-methotrexate enantiomers].

OBJECTIVE: To study the chiral selectivity in vascular endothelial differentiation in drug resistant lung cancer cells induced by high-dose L- or D-methotrexate (MTX) enantiomer. METHODS: Human lung cancer cells of the line A549 were co-cultured with high-dose (15 micromol/L) L- or D-MTX enantiomer so as to develop cancer cells resistant to MTX. MTT method was used to detect the drug resistant index. Flow cytometry was used to detect the expression of CD44, a transmembrane glycoprotein reflecting the migration ability of cells, CD31, a marker of vascular endothelium, and P-170 protein. Fifteen BALB/c nude mice were inoculated with the parent A549 cells, L-MTX-resistant A549 cells induced by L-MTX enantiomer, and D-MTX-resistant A549 cells induced by D-MTX enantiomer. Four weeks later the mice were killed to take out the tumor masses. Immunohistochemistry with CD34 staining was used to detect the microvascular density (MVD). RESULTS: The drug resistant index of the D-MTX induced drug resistant A549 cells was 20.1 +/- 2.3, significantly higher than that of the L-MTX-induced cells (12.4 +/- 1.2, P = 0.000). The CD44 positive rate of the D-MTX induced A549 cells was 97.0% +/- 0.9%, not significantly different from that of the L-MTX-induced A549 cells (96.7% +/- 1.4%, P = 0.544). The CD31 positive rate of the D-MTX induced A549 cells was 91.9% +/- 3.2%, significantly higher than that of the L-MTX-induced A549 cells (32.9% +/- 8.0%, P = 0.000). The P-170 protein positive rate of the parent cells was 85.5% +/- 4.6%, and the P-170 protein positive rate of the D-MTX-induced A549 cells was 87.0% +/- 8.9%, significantly higher than that of the L-MTX-induced cells (71.5% +/- 8.2%, P = 0.002). The MVD of the D-MTX-induced cells was 55.9 +/- 11.9, significantly higher than that of the L-MTX-induced cells (7.2 +/- 1.7, P = 0.000). MVD was significantly positively correlated with the CD31 level (r = 0.462, P = 0.007), and not correlated with P-170 protein and CD34 levels. CONCLUSION: The MTX enantiomers have different chiral selectivity on human lung cancer cell, D-MTX resistant cells shows a potential of differentiation from cancer cells to vascular endothelial cells. D-MTX is not be regarded just as a pollutant in the drug MTX, MTX with single enantiomer (L-MTX) should be selected clinically so as to decrease the side effects of D-MTX.

A novel assay method for theanine synthetase activity by capillary electrophoresis.

The determination of theanine has been performed by micellar electrokinetic capillary chromatography (MECC) using 2,4-dinitrofluorobenzene (DNFB) as a derivative reagent. To achieve the separation, a fused-silica capillary column was used with a borax buffer at 0.03 mol/L pH 9.8 (containing Brij35 and isopropanol) at 17 degrees C with detection wave length at 360 nm. The factors affecting the efficiency of the sample separation were examined simultaneously. A 40-min reaction at 35 degrees C between l-glutamate and ethylamine (with Tris-HCl buffer, pH 7.5) was investigated using the theanine synthetase from budding tea seeds. A novel method for the analysis of theanine synthetase activity based on MECC was established. The method shows mean recovery ranged from 87.1 to 105.3% and linearity ranged from 0.2 to 5.0 mmol/L.

A unified framework for mapping quantitative trait loci in bivalent tetraploids using single-dose restriction fragments: a case study from alfalfa.

The development of statistical methodologies for quantitative trait locus (QTL) mapping in polyploids is complicated by complex polysomic inheritance. In this article, we propose a statistical method for mapping QTL in tetraploids undergoing bivalent formation at meiosis by using single-dose restriction fragments. Our method is based on a unified framework, one that uses chromosome bivalent pairing configuration and gametic recombination to discern different mechanisms of gamete formation. Our bivalent polyploid model can not only provide a simultaneous estimation of the linkage and chromosome pairing configuration-a cytological parameter of evolutionary and systematic interest-but also enhances the precision of estimating QTL effects and position by correctly characterizing gene segregation during polyploid meiosis. By using our method and a linkage map constructed in a previous study, we successfully identify several QTL affecting winter hardiness in bivalent tetraploid alfalfa. Moreover, our results reveal significant preferential chromosome pairing at meiosis in an F1 hybrid population, which indicates the importance of reassessing the traditional view of random chromosome segregation in alfalfa.