Channel Complex Research Articles

Multi-Stimuli-Responsive and Mechano-Actuated Biomimetic Membrane Nanopores Self-Assembled from DNA.

In bioinspired design, biological templates are mimicked in structure and function by highly controllable synthetic means. Of interest are static barrel-like nanopores that enable molecular transport across membranes for use in biosensing, sequencing, and biotechnology. However, biological ion channels offer additional functions such as dynamic changes of the entire pore shape between open and closed states, and triggering of dynamic processes with biochemical and physical stimuli. To better capture this complexity, this report presents multi-stimuli and mechano-responsive biomimetic nanopores which are created with DNA nanotechnology. The nanopores switch between open and closed states, whereby specific binding of DNA and protein molecules as stimuli locks the pores in the open state. Furthermore, the physical stimulus of high transmembrane voltage switches the pores into a closed state. In addition, the pore diameters are larger and more tunable than those of natural templates. These multi-stimuli-responsive and mechanically actuated nanopores mimic several aspects of complex biological channels yet offer easier control over pore size, shape and stimulus response. The designer pores are expected to be applied in biosensing and synthetic biology.

Three-dimensional coking simulation of endothermic hydrocarbon fuels in rectangular cooling channels

Coking deposition is a critical phenomenon for endothermal hydrocarbon fuel cooling that can significantly affect the performance of a regenerative cooling system. Because of the complicated interactions between fluid flow, heat transfer, fuel cracking, and precursor coking kinetics, previous numerical studies have been limited to simplified two-dimensional circular channels, which cannot reveal the actual spatial distribution with consideration of buoyancy effect in rectangular cooling channels. This work proposes a novel framework for shrinking motion with an O-type hybrid mesh, permitting the direct three-dimensional simulation of coke deposition in complex channels and the visualization of both the axial and circumferential deposition distributions. The concept is tested in a rectangular channel using n-decane as an example, combining a detailed pyrolysis kinetic model with the MC-II coking model, and predictive results have been obtained. Results indicate two locations with heavy deposition rates. The buoyancy effect is weakened due to the acceleration resulting from the reduced cross-sectional area of the channel by the coke layer. The coupling of the flow and pyrolysis is discussed in terms of the dimensionless Damköhler number. The maximum temperature after coking can be 138 K higher than the initial. However, the conversion of n-decane at outlet is decreased due to the reduced flow residence time. The decreased total heat sink per temperature increment and the higher pressure drop are also the penalties from coking. The new framework for the direct three-dimensional simulations of coking is significant for the comprehensive investigation of the efficiency of regenerative cooling.

Cloning and functional characterization of a TMC-like channel gene and protein in the crayfish Astacus leptodactylus (Eschscholtz, 1823) (Decapoda: Astacidea: Astacidae)

Abstract Ion channels gated selectively by mechanical stimulus are the key elements of mechanosensation. Several genes have been associated with putative mechanosensitive ion channels or mechanosensitive channel complexes. Transmembrane channel (TMC)-like protein is one of those candidate proteins that have been explored in mammals and several invertebrates. The presence and possible function of TMC related genes has not been investigated yet in crustaceans. In the present work an mRNA coding TMC-like protein was firstly cloned in Astacus leptodactylus (Eschscholtz, 1823) (Decapoda: Astacidea: Astacidae) and expressed in HEK293T cells. Three-dimensional structural calculations of the protein predicted a channel. Functional studies, however, indicated that the mechanosensitivity of the transfected HEK293T cells is similar to that in the control cells. It was concluded that a TMC-like protein is present in the crayfish but future studies are necessary to define its function.

New insights into the depositional facies of the Early Eocene Rus Formation, Bahrain

Detailed geological field measurements combined with petrographic and mineralogical analyses of the Horse Racing Club outcrop, Bahrain, revealed new insights into the composition, facies distribution, and depositional settings of the Early Eocene Rus Formation, which is poorly constrained in Bahrain. The mineralogical analysis revealed that the rock-forming units are dominated by dolomite, dolomitic marl, claystone, and minor evaporites. The integration of field data and lab measurements resulted in the identification of thirteen facies that are grouped into five facies associations comprising i) lagoonal complexes, ii) sabkha complexes, iii) transgressive lag, iv) peritidal channel complexes, and v) barrier island and washover complexes. Combined paleocurrent analysis of field-observed clinoformal structures, lateral accretion surfaces, and trough cross-bedding indicate a NNW–SSE paleoshoreline trend with tidal channels trending dominantly towards NE–SW and NW–SE directions. The depositional facies model developed for the Rus Formation in Bahrain and within the surrounding region suggests that during the Early Eocene, two landmasses existed to the north and south of Bahrain, restricting the Neo-Tethys Ocean flow through a relatively narrow strait that was influenced by periodic storms. The results of this paper challenge the role of the Rus Formation as an effective regional hydrocarbon seal and, as such, highlight the need for a critical evaluation of the associated petroleum system potential in Bahrain and neighboring countries.

Plio-Pleistocene sedimentation and palaeogeographic reconstruction in the Poso Depression, Central Sulawesi, Indonesia: from a sea channel to a land bridge

The Poso Depression provides a record of Plio-Pleistocene environments and palaeogeography of Central Sulawesi. Outcrop-based sedimentological and provenance studies suggest that during the Pliocene the Poso Depression was a sea channel connecting Gorontalo and Bone bays formed in an asymmetric half-graben. The Pliocene history began with deposition of the Puna Formation with fan deltas at the eastern basin margin and channel complexes in the deep-water basin further east. Analyses of light and heavy minerals indicate the main sediment source was ultrabasic rocks in East Sulawesi with minor and intermittent magmatic and metamorphic input from West Sulawesi. Later, in the Middle to Late Pliocene, carbonates of the Poso Formation accumulated on the eastern basin margin. They are unconformably overlain by shallow marine glaucophane-rich siliciclastics of the Pleistocene Lage Formation that are associated with the rapid exhumation and uplift of the Pompangeo metamorphic complex. This uplift led to the development of a land bridge connecting western and eastern Sulawesi. The terrane evolution favoured increasing the area of exposed land due to rapid tectonic uplift, which when combined with the tropical climate, contributed to faunal speciation and dispersal in Sulawesi.

Enhancing heat dissipation and mass transfer of oxygen gas flow channel in a proton exchange membrane fuel cell using multiobjective topology optimization

To enhance the heat dissipation and mass transfer from a proton exchange membrane fuel cell (PEMFC) stack, a multi-objective topology optimization model considering structural deformation, heat transfer, mass diffusion, and gas flow process is proposed herein. The average molar concentration of oxygen and average temperature in the cathode catalyst layer (CL) are considered as the optimization objectives, and the mechanical, mass transfer, and gas flow properties are treated as constraints. The results reveal that compared with a straight gas channel, the topology-optimized configuration leads to an improvement in oxygen molar concentration by 10.36% and reduction in average temperature by 2.26 K. A higher power-dissipation constraint leads to a more complex three-dimensional channel structure with more branches. A larger structural displacement constraint results in a wider and flatter flow channel topology. The average oxygen molar concentration of topologically optimized configurations increases ranging from 5.18 to 14.96%, and the average temperature in the CL decreases about 2.2 K, compared with that of straight gas channel configurations, when the velocity at inlet varies from 0.05 to 0.3 m/s. These findings can aid in the design of PEMFCs.

Basal NAD(H) redox state permits hydrogen peroxide-induced mesenteric artery dilatation.

Smooth muscle voltage-gated K+ (Kv) channels in resistance arteries control vascular tone and contribute to the coupling of blood flow with local metabolic activity. Members of the Kv1 family are expressed in vascular smooth muscle and are modulated upon physiological elevation of local metabolites, including the glycolytic end-product l-lactate and superoxide-derived hydrogen peroxide (H2 O2 ). Here, we show that l-lactate elicits vasodilatation of small-diameter mesenteric arteries in a mechanism that requires lactate dehydrogenase (LDH). Using the inside-out configuration of the patch clamp technique, we show that increases in NADH that reflect LDH-mediated conversion of l-lactate to pyruvate directly stimulate the activity of single Kv1 channels and significantly enhance the sensitivity of Kv1 activity to H2 O2 . Consistent with these findings, H2 O2 -evoked vasodilatation was significantly greater in the presence of 10mM l-lactate relative to lactate-free conditions, yet was abolished in the presence of 10mM pyruvate, which shifts the LDH reaction towards the generation of NAD+ . Moreover, the enhancement of H2 O2 -induced vasodilatation was abolished in arteries from double transgenic mice with selective overexpression of the intracellular Kvβ1.1subunit in smooth muscle cells. Together, our results indicate that the Kvβ complex of native vascular Kv1 channels serves as a nodal effector for multiple redox signals to precisely control channel activity and vascular tone in the face of dynamic tissue-derived metabolic cues. KEY POINTS: Vasodilatation of mesenteric arteries by elevated external l-lactate requires its conversion by lactate dehydrogenase. Application of either NADH or H2 O2 potentiates single Kv channel currents in excised membrane patches from mesenteric artery smooth muscle cells. The binding of NADH enhances the stimulatory effects of H2 O2 on single Kv channel activity. The vasodilatory response to H2 O2 is differentially modified upon elevation of external l-lactate or pyruvate. The presence of l-lactate enhances the vasodilatory response to H2 O2 via the Kvβ subunit complex in smooth muscle.

A new neurodevelopmental disorder linked to heterozygous variants in UNC79

PurposeThe “NALCN channelosome” is an ion channel complex that consists of multiple proteins, including NALCN, UNC79, UNC80, and FAM155A. Only a small number of individuals with a neurodevelopmental syndrome have been reported with disease causing variants in NALCN and UNC80. However, no pathogenic UNC79 variants have been reported, and in vivo function of UNC79 in humans is largely unknown. MethodsWe used international gene-matching efforts to identify patients harboring ultrarare heterozygous loss-of-function UNC79 variants and no other putative responsible genes. We used genetic manipulations in Drosophila and mice to test potential causal relationships between UNC79 variants and the pathology. ResultsWe found 6 unrelated and affected patients with UNC79 variants. Five patients presented with overlapping neurodevelopmental features, including mild to moderate intellectual disability and a mild developmental delay, whereas a single patient reportedly had normal cognitive and motor development but was diagnosed with epilepsy and autistic features. All displayed behavioral issues and 4 patients had epilepsy. Drosophila with UNC79 knocked down displayed induced seizure-like phenotype. Mice with a heterozygous loss-of-function variant have a developmental delay in body weight compared with wild type. In addition, they have impaired ability in learning and memory. ConclusionOur results demonstrate that heterozygous loss-of-function UNC79 variants are associated with neurologic pathologies.

Using association rules analysis to determine favorable mineralization sites in the Jiaojia gold belt, Jiaodong Peninsula, East China

Mesozoic orogenic gold deposits in the Jiaojia goldfield, Eastern China show the features of regular mineralization spatial distribution and have long been captivated the attention of geologists. This study integrates 3D modeling, model space analysis, and association rule analysis to extract the relationship between structural deformation and gold mineralization. The Apriori algorithm with spatial constraints is used to quantify the favorable mineralization sites in the Jiaojia gold field using different combinations of ore-controlling indicators. The first favorable mineralization site has a 44% probability of mineralization and is primarily located in segments of the fault footwall within 25 m of the fault buffer where the transition from steep to gentle occurs (∼1–24). Its uniform distribution indicates that the ore-bearing space near the main fault plane is relatively wide, and hydrothermal diffusion is relatively uniform. Site No. 2 has a 45% probability of mineralization and is located in convex segments (6–35 m) between 25 and 55 m of the fault footwall. The equidistant zonal distribution in this area indicates that secondary faults and fractures have facilitated the migration of hydrothermal fluids, resulting in the formation of extensive ore-bearing spaces. Site No. 3 sited in convex segments (∼0–6 m) distal to the fault footwall (∼55–515 m) of the fault buffer where the dip is gentle (∼30°–35°). The binary structure of differing dips formed by the intersection of steeply dipping orebodies and the slowly dipping orebodies in the central and southern parts of the Nanlü-Xinmu deposit exhibit the complex channel away from the main fault. In this study, the correlation between ore-controlling factors and mineralization in Jiaojia fold field is quantitatively expressed as favorable mineralization sites in the form of association rules, it would contribute to a deeper understanding of the underlying mechanisms governing the formation of structure-controlled orogenic gold deposits in the Jiaojia goldfield.

Molecular Mechanisms of Nuclear Transport of the Neuronal Voltage-gated Ca2+ Channel β3 Auxiliary Subunit

Previous studies have shown that in addition to its role within the voltage-gated calcium channel complex in the plasma membrane, the neuronal CaVβ subunit can translocate to the cell nucleus. However, little is known regarding the role this protein could play in the nucleus, nor the molecular mechanism used by CaVβ to enter this cell compartment. This report shows evidence that CaVβ3 has nuclear localization signals (NLS) that are not functional, suggesting that the protein does not use a classical nuclear import pathway. Instead, its entry into the nucleus could be associated with another protein that would function as a carrier, using a mechanism known as a piggyback. Mass spectrometry assays and bioinformatic analysis allowed the identification of proteins that could be participating in the entry of CaVβ3 into the nucleus. Likewise, through proximity ligation assays (PLA), it was found that members of the heterogeneous nuclear ribonucleoproteins (hnRNPs) and B56δ, a regulatory subunit of the protein phosphatase 2A (PP2A), could function as proteins that regulate this piggyback mechanism. On the other hand, bioinformatics and site-directed mutagenesis assays allowed the identification of a functional nuclear export signal (NES) that controls the exit of CaVβ3 from the nucleus, which would allow the completion of the nuclear transport cycle of the protein. These results reveal a novel mechanism for the nuclear transport cycle of the neuronal CaVβ3 subunit.

Active Zone Trafficking of CaV2/UNC-2 Channels Is Independent of β/CCB-1 and α2δ/UNC-36 Subunits.

The CaV2 voltage-gated calcium channel is the major conduit of calcium ions necessary for neurotransmitter release at presynaptic active zones (AZs). The CaV2 channel is a multimeric complex that consists of a pore-forming α1 subunit and two auxiliary β and α2δ subunits. Although auxiliary subunits are critical for channel function, whether they are required for α1 trafficking is unresolved. Using endogenously fluorescent protein-tagged CaV2 channel subunits in Caenorhabditis elegans, we show that UNC-2/α1 localizes to AZs even in the absence of CCB-1/β or UNC-36/α2δ, albeit at low levels. When UNC-2 is manipulated to be trapped in the endoplasmic reticulum (ER), CCB-1 and UNC-36 fail to colocalize with UNC-2 in the ER, indicating that they do not coassemble with UNC-2 in the ER. Moreover, blocking ER-associated degradation does not further increase presynaptic UNC-2 channels in ccb-1 or unc-36 mutants, indicating that UNC-2 levels are not regulated in the ER. An unc-2 mutant lacking C-terminal AZ protein interaction sites with intact auxiliary subunit binding sites displays persistent presynaptic UNC-2 localization and a prominent increase of UNC-2 channels in nonsynaptic axonal regions, underscoring a protective role of auxiliary subunits against UNC-2 degradation. In the absence of UNC-2, presynaptic CCB-1 and UNC-36 are profoundly diminished to barely detectable levels, indicating that UNC-2 is required for the presynaptic localization of CCB-1 and UNC-36. Together, our findings demonstrate that although the pore-forming subunit does not require auxiliary subunits for its trafficking and transport to AZs, it recruits auxiliary subunits to stabilize and expand calcium channel signalosomes.SIGNIFICANCE STATEMENT Synaptic transmission in the neuron hinges on the coupling of synaptic vesicle exocytosis with calcium influx. This calcium influx is mediated by CaV2 voltage-gated calcium channels. These channels consist of one pore-forming α1 subunit and two auxiliary β and α2δ subunits. The auxiliary subunits enhance channel function and regulate the overall level of channels at presynaptic terminals. However, it is not settled how these auxiliary subunits regulate the overall channel level. Our study in C. elegans finds that although the auxiliary subunits do not coassemble with α1 and aid trafficking, they are recruited to α1 and stabilize the channel complex at presynaptic terminals. Our study suggests that drugs that target the auxiliary subunits can directly destabilize and have an impact on CaV2 channels.

Modulation format recognition in a UVLC system based on reservoir computing with coordinate transformation and folding algorithm.

Modulation format recognition (MFR) is one of the key technologies in adaptive optical systems and widely used in both commercial and civil applications. With the rapid development of deep learning, MFR algorithm based on neural networks (NN) has achieved impressive success. Due to the high complexity of underwater channels, to gain better performance of MFR tasks in underwater visible light communication (UVLC), the NN tend to be designed with a complex structure, which is costly in computation and hinders fast allocation and real-time processing. In this paper, we propose a lightweight and efficient method based on reservoir computing (RC), whose trainable parameters are only 0.3% of common NN-based methods. To improve the performance of RC in MFR tasks, we propose powerful feature extraction algorithms including coordinate transformation and folding algorithm. The proposed RC-based methods are implemented for six modulation formats, including OOK, 4QAM, 8QAM-DIA, 8QAM-CIR, 16APSK, and 16QAM. The experimental results show that our RC-based methods take only a few seconds for training process and under different pin voltages of LED, the accuracy for almost all exceeds 90%, and the highest is close to 100%. Analysis on how to design a well-performed RC to strike a balance between accuracy and time cost is also investigated, providing a useful guide for RC implementations in MFR.

Sensitivity analysis of seismic attributes parametrization to reduce misinterpretations: Applications to deepwater channel complexes

Geoscientists apply algorithms such as seismic attributes to better interpret depositional systems that enhance various aspects of the seismic data. However, they are limited by the original seismic amplitude or frequency content, data quality, and algorithm parameters considered.Additionally, our capacity to interpret depositional system architecture is limited by seismic resolution, which results in potential misinterpretations associated with the correct position of stratigraphic features. Resolution also sets a minimum thickness that can be observed in seismic data. This is particularly important as mapping reservoir architecture (geobody size, shape, and stacking patterns) in the subsurface is critical for exploring and producing hydrocarbons, CO2 storage, and geothermal resource development since it can define connectivity or compartmentalization of flow zones.To address these concerns, we investigated five synthetic seismic volumes from low to high-dominant frequencies of 15 Hz, 30 Hz, 60 Hz, 90 Hz, and 180 Hz based on an architectural model of an outcropping deepwater channelized slope system in the Magallanes Basin, Chile. We analyzed 1) how seismic bandwidth affects the resolution of stacked stratigraphic features (i.e., deepwater channel elements and Mass Transport Deposits (MTDs)) and their subsequent seismic interpretation, and 2) the effect of different seismic attributes commonly employed in channel interpretation on our data to understand the “mixing” or “vertical smearing” of stratigraphic features by comparing the seismic with the true geological model 3) we explored how the attributes’ parametrization affects the imaging of differently sized features by modifying the analysis window in each case from ± 2ms to ± 50 ms. Finally, 4) we evaluated the effect of different noise levels in the sensitivity analysis. Resultsshow that the “mixing” of events occurs mainly as a result of 1) the seismic bandwidth, 2) the algorithm used for each seismic attribute calculation, 3) the attribute vertical analysis window, and 4) the signal-to-noise ratio of the data. Broadband, higher frequency data, and small analysis windows provide clearer images of the stacked channels. In contrast, low-frequency data and larger analysis windows result in more mixing or “composite” appearances, affecting interpretations and net-to-gross estimates, especially in small-size stratigraphic features such as individual channel elements and Mass Transport Deposits (MTDs). Our observations warn of potential misinterpretations in applying default attributes to actual seismic data, especially in geometrical attributes and window-dependent ones. Recognizing these misinterpretations is paramount for reconstructing deepwater architecture (this study), sedimentary and structural studies for drilling locations, reserves estimation, and overall uncertainty assessment.

PO-455617-2 UNRAVELLING THE ARRHYTHMOGENIC MECHANISMS OF SHORT QT SYNDROME TYPE 3 IN AN ANIMAL MODEL OF KIR2.1M301K GAIN-OF-FUNCTION MUTATION

Short QT Syndrome Type 3 (SQTS3) is an extremely rare, highly arrhythmogenic disease caused by gain-of-function mutations in the KCNJ2 gene coding the inward rectifier potassium channel Kir2.1. We investigated arrhythmogenic mechanisms associated with the mutation Kir2.1M301K in a patient presenting an extremely abbreviated QT interval, paroxysmal atrial fibrillation, and ventricular fibrillation inducibility. To study mechanisms of life-threatening arrhythmias produced by Kir2.1M301K. We tested the hypothesis that, in addition to abolishing IK1 rectification, Kir2.1M301K produces functional defects in Kir2.1 partner proteins, predisposing patients to an arrhythmogenic phenotype. We used intravenous cardiac-specific adeno-associated virus-mediated gene transfer to generate mice expressing wild-type (WT) and M301K mutant channel. We characterized the mice using molecular and cellular biology techniques, electrocardiograms (ECGs), intracardiac stimulation and patch-clamping. We confirmed Kir2.1WT or Kir2.1M301K gene expression specifically in the mouse heart. On ECG, the corrected QT (QTc) interval of Kir2.1M301K mice was significantly shorter than Kir2.1WT mice (p<0.0001), and the QRS complex was prolonged (p<0.01). On intracardiac stimulation, 7 out of 8 Kir2.1M301K mice had inducible ventricular tachycardia/fibrillation of >500ms duration, while none of 10 Kir2.1WT mice were inducible (p=0.0009). Compared with Kir2.1WT, the current/voltage relation of Kir2.1M301K cardiomyocytes showed increased outward IK1 at voltages positive to -80 mV (p<0.0001) with no inward-going rectification. However, inward IK1 was reduced at voltages negative to -80 mV (p=0.006). Unexpectedly, Kir2.1M301K cardiomyocytes had a reduced INa density (p<0.0001) with voltage shifted activation and inactivation. Membrane fractionation and western blot analysis revealed that, while 100% of NaV1.5 channels reached the membrane in Kir2.1WT cardiomyocytes, only 77% did in Kir2.1M301K cardiomyocytes. The Kir2.1M301K mouse recapitulates the arrhythmogenic phenotype of the SQTS3 patient. Kir2.1M301K mutation produces both Kir2.1 and NaV1.5 dysfunction, confirming the reciprocal modulation of these channels in macromolecular complexes. This is the first demonstration that a KCNJ2 gain-of-function mutation modifies NaV1.5 current, thus producing severe arrhythmias by both shortening QT interval and reducing ventricular excitability.

A Novel Maximum Distance Separable Coded OFDM-RIS for 6G Wireless Communications

The vision of the sixth generation mobile communication (6G) calls for extremely reliable data transmission over complex and diverse wireless channels. By combining the maximum distance separable (MDS) codes with the classic orthogonal frequency division multiplexing (OFDM), we present a new paradigm with the assistance of the reconfigurable intelligent surfaces (RIS). In our design, the RIS with limited phase shifts are adopted and the pairwise error probability (PEP) of the proposed system is first derived. Then, in order to further minimize the bit error rate (BER), we provide a novel method based on phase alignment to obtain the optimal solution for the discrete phase shifts. Our simulation results show that the proposed scheme provides considerable BER performance improvements compared to conventional OFDM systems. Moreover, the proposed discrete phase optimization algorithm is capable of achieving performance similar to that of the system with continuous phase shifts.

DOA Estimation of Underwater Acoustic Array Signal Based on Wavelet Transform With Double Branch Convolutional Neural Network

In underwater acoustic communications, a hydrophone array is often used to receive the underwater acoustic signals to improve the gain of the received signal. The direction of arrival (DOA) estimation is a basic task in underwater acoustic array signal processing. In underwater signal transmission, due to the channel complexity, a large signal transmission loss, and heavy noise interference, the received signal is seriously distorted, and the DOA estimation is poor. In order to improve the accuracy of DOA estimation for underwater acoustic array signals, in this work, we propose continuous wavelet transform with convolutional neural network (CWT-CNN) method. We use a linear factor to improve the calculation process of continuous wavelet transform. The characteristics of time-frequency fusion of signals are calculated by constructing time-frequency array model with modified wavelet factors. The fused features are then used to train the proposed double branch CNN. As compared with other DOA algorithms based on neural networks, the proposed algorithm shows a 5%–20% higher accuracy and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$0.479^{\circ }-1.172^{\circ }$</tex-math></inline-formula> lower RMSE at 7 different values of SNR. In addition, the proposed algorithm is less computationally complex.

The Role of RNA Methylation Modification Related Genes in Prognosis and Immunotherapy of Colorectal Cancer.

Researches showed RNA methylation genes can affect the prognosis of tumors. Thus, the study aimed to comprehensively analyze the effects of RNA methylation regulatory genes in prognosis and treatment of colorectal cancer (CRC). Prognostic signature associated with CRCs were constructed by differential expression analysis, Cox and Least Absolute Shrinkage and Selection Operator (LASSO) analyses. Receiver operating characteristic (ROC) and Kaplan-Meier survival analyses were used to validate the reliability of the developed model. Gene Ontology (GO), Gene set variation analysis (GSVA), and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed for functional annotation. Finally, normal and cancerous tissue were collected to validate gene by quantitative real-time PCR (qRT-PCR). A prognostic risk model based on leucine rich pentatricopeptide repeat containing (LRPPRC) and ubiquitin-like with PHD and ring finger domains 2 (UHRF2) was constructed and relevant to the overall survival (OS) of CRC. Functional enrichment analysis revealed that collagen fibrous tissue, ion channel complex and other pathways were significantly enriched, which might help explain the underlying molecular mechanisms. There were significant differences in ImmuneScore, StromalScore, ESTIMATEScore between high- and low-risk groups (p < 0.05). Ultimately, qRT-PCR validation showed that a significant upregulation in the expression of LRPPRC and UHRF2 in cancerous tissue, which verified the effectiveness of our signature. In conclusion, 2 prognostic genes (LRPPRC and UHRF2) related to RNA methylation were identified by bioinformatics analysis, which might supply a new insight into the treatment and evaluation of CRC.

Channel Tracking for RIS-Aided mmWave Communications Under High Mobility Scenarios

The emerging reconfigurable intelligent surface (RIS) technology is promising for applications in the millimeter wave (mmWave) communication systems to effectively compensate for propagation loss or tackle the blockage issue. Considering the high mobility of users in realistic scenarios, it is essential to adjust the phase shifts in real time to align the beam towards the mobile users, which requires to frequently estimate the channel state information. Hence, it is imperative to design efficient channel tracking schemes to avoid the complex channel estimation procedure. In this paper, we develop a novel channel tracking scheme with two advantages over conventional schemes. First, our tracking scheme is based on the cascaded angles at the RIS instead of the accurate angle values, which is more practical. Second, it can be employed under a more general setting where the noise can be non-Gaussian. Simulation results show the high tracking accuracy of our proposed scheme, and validate the superiority to the existing EKF-based tracking scheme.

System Performance Analysis of Sensor Networks for RF Energy Harvesting and Information Transmission

This paper investigates the problem of RF energy harvesting in wireless sensor networks, with the aim of finding a suitable communication protocol by comparing the performance of the system under different protocols. The network is made up of two parts: first, at the beginning of each timeslot, the sensor nodes harvest energy from the base station (BS) and then send packets to the BS using the harvested energy. For the energy-harvesting part of the wireless sensor network, we consider two methods: point-to-point and multi-point-to-point energy harvesting. For each method, we use two independent control protocols, namely head harvesting energy of each timeslot (HHT) and head harvesting energy of dedicated timeslot (HDT). Additionally, for complex channel states, we derive the cumulative distribution function (CDF) of packet transmission time using selective combining (SC) and maximum ratio combining (MRC) techniques. Analytical expressions for system reliability and packet timeout probability are obtained. At the same time, we also utilize the Monte Carlo simulation method to simulate our system and have analyzed both the numerical and simulation solutions. Results show that the performance of the HHT protocol is better than that of the HDT protocol, and the MRC technology outperforms the SC technology for the HHT protocol in terms of the energy-harvesting efficiency coefficient, sensor positions, transmit signal-to-noise ratio (SNR), and length of energy harvesting time.

All fabric and flexible wearable sensors for simultaneous sweat metabolite detection and high-efficiency collection

Wearable sweat electrochemical sensors have attracted wide attention due to their advantages of non-invasive, portable, real-time monitoring, etc. However, existing sensors still have some problems with efficient sweat collection. Microfluidic channel technology and electrospinning technology are commonly used to collect sweat efficiently, but there are some limitations such as complex channel design and multiple spinning parameters. Besides, existing sensors are mostly based on flexible polymers, such as, PET, PDMS, PI and PI, which have limited wearability and permeability. Based on the above, all fabric and dual-function flexible wearable sweat electrochemical sensor is proposed in this paper. This sensor uses fabric as the raw material to implement the directional transport of sweat and the multi-component integrated detection dual functions. Meanwhile, the high-efficiency collection of sweat is obtained by a Janus fabric, wherein one side of the selected silk is superhydrophobic graft treated and the other side is hydrophilic plasma treated. Therefore, the resulting Janus fabric can effectively transfer sweat from the skin side to the electrode, and the minimum sweat droplet can reach 0.2 μL to achieve micro-volume collection. Besides, the patterned sensor, made of silk-based carbon cloth, is fabricated using a simple laser engraving, which could detect Na+, pH, and glucose instantaneously. As a result, these proposed sensors can achieve good sensing performance and high-efficiency sweat collection dual functionality; moreover, it has good flexibility and comfortable wearability.