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On the basis of extensive reading of domestic and foreign literature and full investigation, this paper studies the theories related to mobile learning. Based on these theories, the resource service model of cloud education resources and the mode of mobile English learning are designed, which forms the problem of identification and confirmation with practitioners. Design models and solutions produce new theories of mobile learning. On the system architecture, the system is divided into four layers to improve the flexibility and scalability of system services. Considering the security of system services, a set of session caching system is designed and proposes a service interface encryption scheme based on Sessionid, Timestamp, and public Key. Finally, this paper realizes the mobile English client and background management platform. English mobile platform is used widely for teachers and students on campus, so the pressure-bearing capacity of the system service is tested and verified. The results show that the running stability of this system can reach about 96.03%. Its bearing capacity is strong, reaching the expected goal, which can provide some reference for related research.

Background: The aim of this study was to assess the association between pet ownership and threatened abortion (TA) in pregnant Chinese women. Materials and Methods: We enrolled pregnant women from 18 provinces and autonomous regions across China between November 2017 and December 2020. Participants were grouped based on the presence or absence of pet ownership. Pet owners were further sub-grouped based on the presence or absence of close contact with their pets. Pet species included cats, dogs, and both. Generalised linear mixed models, with province as a random effect, were used to estimate the associations between pet ownership and TA. Results: Pet ownership, whether or not one had close contact with pets, was associated with greater odds of TA (OR: 1.30, 95% CI: 1.21, 1.40). Keeping pet cats (OR: 1.24, 95% CI: 1.11, 1.40), dogs (OR: 1.29, 95% CI: 1.18, 1.41), or both cats and dogs (OR: 1.36, 95% CI: 1.04, 1.68) during pregnancy were all risk factors for TA. We observed significant group differences (p for difference < 0.05) in pre-pregnancy body mass index, education levels, and annual household income. Conclusions: Cat or dog ownership during pregnancy was associated with an increased risk of TA, especially among overweight, less educated, or lower-income participants.

In the process of evolution to the next generation network, wireless is an indispensable technology. Because of its Multi-Hop characteristics, the application value of Wireless Mesh Network in the next generation Internet has been proved. Because of Mesh peer-to-peer network topology, if a node fails, it will not affect the operation of the whole network, and can effectively avoid single point of failure. As a solution to provide high-speed internet services, Wireless Mesh Network can provide network access for mobile users in its coverage area, and it has evolved into an effective solution for broadband home networks, community networks, enterprise networks and other wireless access networks.

Flower recognition has important application value in the field of flower cultivation and planting. As a kind of fine-grained image recognition, the traditional flower recognition has the problem of low recognition accuracy. In order to solve these problems, this paper proposes a neural network algorithm of ResNet structure that integrates CBAM mechanism, and adds residual blocks of attention modules to the second layer to the fifth layer of the ResNet structure. Finally, the results are output through adaptive average pooling and full connection layer. Experimental results show that the recognition accuracy of the model is close to 98% even when the recognition is difficult and there are few training data. Compared with the traditional deep learning model, the model proposed in this paper significantly improves the recognition accuracy.

The first complete chloroplast genome (cpDNA) sequence of Caryodaphnopsis tonkinensis was determined from Illumina HiSeq pair-end sequencing data in this study. The cpDNA is 149,016 bp in length, c...

The first complete chloroplast genome (cpDNA) sequence of Cinnamomum longipetiolatum was determined from Illumina HiSeq pair-end sequencing data in this study. The cpDNA is 158,603 bp in length, contains a large single copy region (LSC) of 89,386 bp and a small single copy region (SSC) of 18,181 bp, which were separated by a pair of inverted repeats (IR) regions of 25,511 bp. The genome contains 129 genes, including 84 protein-coding genes, eight ribosomal RNA genes, and 37 transfer RNA genes. The overall GC content of the whole genome is 39.0%, and the corresponding values of the LSC, SSC, and IR regions are 37.7%, 33.9%, and 43.0%, respectively. Further phylogenomic analysis showed that C. longipetiolatum clustered in a clade in genus Cinnamomum.

Single-cell electrical properties (e.g., specific membrane capacitance (Cspecific membrane) and cytoplasm conductivity (σcytoplasm)) have been regarded as potential label-free biophysical markers for the evaluation of cellular status. However, whether there exist correlations between these biophysical markers and cellular status (e.g., membrane-associate protein expression) is still unknown. To further validate the utility of single-cell electrical properties in cell type classification, Cspecific membrane and σcytoplasm of single PC-3 cells with membrane staining and/or fixation were analyzed and compared in this study. Four subtypes of PC-3 cells were prepared: untreated PC-3 cells, PC-3 cells with anti-EpCAM staining, PC-3 cells with fixation, and fixed PC-3 cells with anti-EpCAM staining. In experiments, suspended single cells were aspirated through microfluidic constriction channels with raw impedance data quantified and translated to Cspecific membrane and σcytoplasm. As to experimental results, significant differences in Cspecific membrane were observed for both live and fixed PC-3 cells with and without membrane staining, indicating that membrane staining proteins can contribute to electrical properties of cellular membranes. In addition, a significant decrease in σcytoplasm was located for PC-3 cells with and without fixation, suggesting that cytoplasm protein crosslinking during the fixation process can alter the cytoplasm conductivity. Overall, we have demonstrated how to classify single cells based on cellular electrical properties.

This paper presents a microfluidic system enabling continuous characterization of instantaneous Young's modulus ( E instantaneous ) of single cells in suspension. In this study, cells were aspirated continuously through a constriction channel while cellular entry processes were monitored using a high-speed camera. Numerical simulations were conducted to model cellular entry process into the constriction channel where a visco-hyperelastic solid was used to model biological cells and the cellular friction with the constriction channel wall ( ƒ c ) was properly addressed. Both experimental observations and numerical simulations confirmed the two-stage cellular entry process into the constriction channel: an instantaneous jump into the channel quantified by instantaneous aspiration length ( L instantaneous ) followed by a creeping increase in aspiration length terminated by transitional aspiration length ( L transitional ). Numerical simulations reveal that L instantaneous and L transitional are reversely proportional to E instantaneous , which are affected by ƒ c regardless of other cellular viscoelastic parameters. By combining measured L instantaneous and L transitional with these obtained from numerical simulations, E instantaneous and ƒ c were quantified as 3.48 ± 0.86 kPa and 0.39 ± 0.11 for A549 cells ( n cell = 199) and 2.99 ± 0.38 kPa and 0.37 ± 0.02 for 95C cells ( n cell = 164). As a platform technology, this method can be used to characterize E instantaneous of various cell types in a continuous manner for cellular biophysical property characterization.

a b s t r a c t This study reports a microfluidic platform for clogging-free electrical property analysis of single cells. A pneumatically driven membrane-based active valve was integrated in this platform to unblock clogging events of constriction microchannels where pneumatic pressures were used to tune the deformation of a polydimethylsiloxan (PDMS) membrane serving as one wall of the constriction microchannel. The proposed platform was first tested to unblock trapped polystyrene beads at the entrance of constriction microchannels and then the characterization of the cellular electrical properties of lung cancer cells was successfully demonstrated. Results showed that the measured cytoplasm conductivity (0.74 ± 0.20 S/m) and specific membrane capacitance (2.17 ± 0.58 F/cm2) of cells were consistent with the results from the previous publications (0.73 ± 0.17 S/m, and 2.00 ± 0.60 F/cm 2 , respectively). Overall, this study has presented a microfluidic platform for single cell analysis with an enhanced function for unblocking cell aggregates at the entrance of microchannels.

This paper presents a microfluidics-based approach capable of continuously characterizing instantaneous Young's modulus (E(instantaneous)) and specific membrane capacitance (C(specific membrane)) of suspended single cells. In this method, cells were aspirated through a constriction channel while the cellular entry process into the constriction channel was recorded using a high speed camera and the impedance profiles at two frequencies (1 kHz and 100 kHz) were simultaneously measured by a lock-in amplifier. Numerical simulations were conducted to model cellular entry process into the constriction channel, focusing on two key parameters: instantaneous aspiration length (L(instantaneous)) and transitional aspiration length (L(transitional)), which was further translated to E(instantaneous). An equivalent distribution circuit model for a cell travelling in the constriction channel was used to determine C(specific membrane). A non-small-cell lung cancer cell line 95C (n = 354) was used to evaluate this technique, producing E(instantaneous) of 2.96 ± 0.40 kPa and Cspecific membrane of 1.59 ± 0.28 μF/cm2. As a platform for continuous and simultaneous characterization of cellular E(instantaneous) and C(specific membrane), this approach can facilitate a more comprehensive understanding of cellular biophysical properties.

This paper presents a microfluidic system enabling continuous characterization of specific membrane capacitance (Cspecific membrane) and cytoplasm conductivity (σcytoplasm) of single cells by aspirating cells continuously through a constriction channel with cell elongations and impedance profiles at two frequencies (1 kHz and 100 kHz) measured simultaneously. 1 kHz impedance data were used to evaluate cellular sealing properties and 100 kHz impedance data were used to quantify membrane capacitance and cytoplasm conductance, which were than translated to Cspecific membrane and σcytoplasm based on the proposed equivalent circuit model. Four cell lines were used to evaluate this technique, producing Cspecific membrane and σcytoplasm of 3.81±0.90 μF/cm2 and 0.49±0.07 S/m (CRL-5803, n=489), 4.28±1.05 μF/cm2 and 0.45±0.08 S/m (CCL-185, n=487), 3.67±1.00 μF/cm2 and 0.47±0.09 S/m (CRL-1932, n=302), as well as 4.53±1.51 μF/cm2 and 0.55±0.14 S/m (CRL-1999, n=216), respectively.

This paper presents a microfluidic system enabling cell type classification based on continuous characterization of size-independent electrical properties (e.g., specific membrane capacitance (C(specific membrane)) and cytoplasm conductivity (σ(cytoplasm)). In this study, cells were aspirated continuously through a constriction channel, while cell elongation and impedance profiles at two frequencies (1 kHz and 100 kHz) were measured simultaneously. Based on a proposed distributed equivalent circuit model, 1 kHz impedance data were used to evaluate cellular sealing properties with constriction channel walls and 100 kHz impedance data were translated to C(specific membrane) and σ(cytoplasm). Two lung cancer cell lines of CRL-5803 cells (n(cell) = 489) and CCL-185 cells (n(cell) = 487) were used to evaluate this technique, producing a C(specific membrane) of 1.63 ± 0.52 μF cm(-2) vs. 2.00 ± 0.60 μF cm(-2), and σ(cytoplasm) of 0.90 ± 0.19 S m(-1)vs. 0.73 ± 0.17 S m(-1). Neural network-based pattern recognition was used to classify CRL-5803 and CCL-185 cells, producing success rates of 65.4% (C(specific membrane)), 71.4% (σ(cytoplasm)), and 74.4% (C(specific membrane) and σ(cytoplasm)), suggesting that these two tumor cell lines can be classified based on their electrical properties.

This paper presents a microfluidic system enabling continuous characterization of specific membrane capacitance (Cspecific membrane) and cytoplasm conductivity (σcytoplasm) of single biological cells. In this study, cells were aspirated through a constriction channel while cell elongations and impedance profiles at 1 kHz and 100 kHz were measured simultaneously using microscopy imaging and a lock-in amplifier. Based on the proposed equivalent circuit model, raw data were translated to Cspecific membrane and σcytoplasm, which were 3.67±1.00 vs. 4.53±1.51 μF/cm2 and 0.47±0.09 vs. 0.55±0.14 S/m for the kidney tumor cell line of 786-O (n=302) and the vascular smooth muscle cell line of T2 (n=216), respectively.

This paper presents a microfluidic system enabling continuous characterization of specific membrane capacitance (Cspecific membrane) and cytoplasm conductivity (σcytoplasm) of single cells in suspension. In this study, cells were aspirated continuously through a constriction channel while cell elongations and impedance profiles at two frequencies (1kHz and 100kHz) were measured simultaneously using microscopy imaging and a lock-in amplifier. 1kHz impedance data were used to evaluate cellular sealing properties with constriction channel walls and 100kHz impedance data were translated to quantify equivalent membrane capacitance and cytoplasm resistance of single cells, which were further translated to Cspecific membrane and σcytoplasm. Two model cell lines (kidney tumor cell line of 786-O (n=302) and vascular smooth muscle cell line of T2 (n=216)) were used to evaluate this technique, producing Cspecific membrane of 3.67±1.00 and 4.53±1.51μF/cm(2) and σcytoplasm of 0.47±0.09 and 0.55±0.14S/m, respectively. Compared to previously reported techniques which can only collect Cspecific membrane and σcytoplasm from tens of cells, this new technique has a higher throughput, capable of collecting Cspecific membrane and σcytoplasm from hundreds of cells in 30min immediately after cell passage.