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The assembly of functional biomolecular condensates often involves liquid-liquid phase separation (LLPS) of proteins with multiple modular domains, which can be folded or conformationally disordered to various degrees. To understand the LLPS-driving domain-domain interactions, a fundamental question is how readily the interactions in the condensed phase can be inferred from inter-domain interactions in dilute solutions. In particular, are the interactions leading to LLPS exclusively those underlying the formation of discrete inter-domain complexes in homogeneous solutions? We address this question by developing a mean-field LLPS theory of two stoichiometrically constrained solute species. The theory is applied to the neuronal proteins SynGAP and PSD-95, whose complex coacervate serves as a rudimentary model for neuronal postsynaptic densities (PSDs). The predicted phase behaviors are compared with experiments. Previously, a three-SynGAP, two-PSD-95 ratio was determined for SynGAP/PSD-95 complexes in dilute solutions. However, when this 3:2 stoichiometry is uniformly imposed in our theory encompassing both dilute and condensed phases, the tie-line pattern of the predicted SynGAP/PSD-95 phase diagram differs drastically from that obtained experimentally. In contrast, theories embodying alternate scenarios postulating auxiliary SynGAP-PSD-95 as well as SynGAP-SynGAP and PSD-95-PSD-95 interactions in addition to those responsible for stoichiometric SynGAP/PSD-95 complexes produce tie-line patterns consistent with experiment. Hence, our combined theoretical-experimental analysis indicates that weaker interactions or higher-order complexes beyond the 3:2 stoichiometry, but not yet documented, are involved in the formation of SynGAP/PSD-95 condensates, imploring future efforts to ascertain the nature of these auxiliary interactions in PSD-like LLPS., Comment: 38 pages, 5 figures. Accepted for publication in Biophysical Journal

The urban–rural system is an economically, socially, and environmentally interlinked space, which requires the integration of industry, space, and population. To achieve sustainable and coordinated development between urban and rural systems, dynamic land use change within the urban–rural system and the ecological and social consequences need to be clarified. This study uses system resilience to evaluate such an impact and explores the impact of land use change, especially land conversion induced by urbanization on regional development through the lens of urban–rural resilience. The empirical case is based on the Beijing-Tianjin-Hebei Urban Agglomeration (BTHUA) in China from 2000 to 2020 when there was rapid urbanization in this region. The results show that along with urbanization in the BTHUA, urban–rural resilience is high in urban core areas and low in peripheral areas. From the urban core to the rural outskirts, there is a general trend that comprehensive resilience decreases with decreased social resilience and increased ecological resilience in this region. Specifically, at the city level, comprehensive resilience decreases sharply from the urban center to its 3–5 km buffer zone and then remains relatively stable in the rural regions. A similar trend goes for social resilience at the city level, while ecological resilience increases sharply from the urban center to its 1–3 km buffer zone, and then remains relatively stable in the rural regions in this region, except for cities in the west and south of Hebei. This study contributes to the conceptualization and measurement of urban–rural resilience in the urban–rural system with empirical findings revealing the impact of rapid urbanization on urban–rural resilience over the last twenty years in the BTHUA in China. In addition, the spatial heterogeneity results could be used for policy reference to make targeted resilience strategies in the study region.

This work investigates the security issue of the energy-constrained untrusted relay network with imperfect channel reciprocity, where the relay without the built-in power supply can only scavenge energy from radio-frequency signals radiated by the source and destination. A hybrid power-splitting (PS)- and time-switching (TS)-based relaying (HPTR) protocol is presented to improve the degraded secrecy performance due to the incomplete self-interference cancellation at the destination. To evaluate the secrecy throughput (ST) of the studied system, the analytical expression of the secrecy outage probability under the delay-limited transmission mode and the closed-form lower bound of the ergodic secrecy capacity under delay-tolerant transmission mode are derived. Both linear and nonlinear models for the energy harvester at the relay are compared. The optimal PS and TS ratios are evaluated numerically. The theoretical derivations are validated by numerical results, revealing that the residual jamming has a negative effect on the secrecy performance of untrusted relay networks, which can be alleviated by the HPTR protocol. Besides, we compare the ST performance of the HPTR protocol with that of the PS and TS relaying schemes, and the results show that the HPTR protocol outperforms both PS and TS relaying protocols in terms of the ST.

Spermatogenesis is a highly coordinated process that initiates shortly after birth and continues throughout the lifespan of male animals. Foxo1 is a transcription factor and is involved in many biological processes. It has been reported that the inactivation of Foxo1 in gonocytes during the embryonic stage causes the defects of spermatogenesis. In the present study, we found that the inactivation of Foxo1 in spermatogonia after birth also caused germ cell loss and male infertility. We found that the initiation of meiosis was not affected; however, the germ cell development was arrested after meiosis and lack of mature spermatozoa in the cauda epididymis. We also found that the proliferation of Foxo1-deficient spermatogonia stem cells was significantly reduced under in vitro conditions. Further study revealed that inactivation of Pten in postnatal spermatogonia using Stra8-Cre did not affect germ cell development and the subcellular location of FOXO1 in Pten-deficient spermatogonia. This study demonstrated that Foxo1 was involved in the development of spermatogonia after birth and the function of Foxo1 was probably not regulated by PI3K/PTEN signaling.

The simultaneous wireless information and power transfer (SWIPT) has recently attracted much attention since both information and energy are integrated within radio frequency signals, which is considered to be one of the most important technologies for future networks. However, security becomes one of the most critical issues in SWIPT networks due to its broadcasting features over wireless media and the transferring requirements for strong signal strength. To improve the security of SWIPT networks, in this paper, a SWIPT system enabled by full-duplex (FD) jamming is proposed, where an FD energy-limited receiver with the power splitting (PS) structure, powered by a transmitter, generates jamming signals. Both linear and nonlinear energy harvesting (EH) models are considered. To evaluate the secrecy throughput (ST) of the system, we derive the closed-form connection outage probability and secrecy outage probability for the proposed PS-based scheme in the delay-constrained transmission (DCT) mode. The ST is maximized by optimizing the PS ratio based on the asymptotic cases of the high signal-to-noise ratio as well as the perfect self-interference cancellation (SIC). Besides, the exact integral forms of the ergodic secrecy capacity and their closed-form lower bounds are presented for both the PS-based and the time switching (TS)-based schemes in the delay-tolerant transmission (DTT) mode. Simulation results suggest that the PS-based scheme outperforms the TS-based scheme for the DTT mode. For the DCT mode, the PS-based scheme can achieve better performance than the TS-based scheme only in low target communication rate, small PS/TS ratio, high transmit power, and weak path loss. Meanwhile, given a tolerable amount of SIC, the ST obtained in the linear EH model is higher than that achieved in the nonlinear EH model.

The SynGAP/PSD-95 binary protein system serves as a simple mimicry of postsynaptic densities (PSDs), which are protein assemblies based largely on liquid-liquid phase separation (LLPS), that are located underneath the plasma membrane of excitatory synapses. Surprisingly, the LLPS of the SynGAP/PSD-95 system is much more pressure sensitive than typical folded states of proteins or nucleic acids. It was found that phase-separated SynGAP/PSD-95 droplets dissolve into a homogeneous solution at a pressure of tens to hundred bar. Since organisms in the deep sea are exposed to pressures of up to ∼1000 bar, this observation suggests that deep-sea organisms must counteract the high pressure sensitivity of PSDs to avoid neurological impairment. We demonstrate here that the compatible osmolyte trimethylamine-N-oxide (TMAO) as well as macromolecular crowding agents at moderate concentrations can mitigate the deleterious effect of pressure on SynGAP/PSD-95 droplet stability, extending stable LLPS up to almost a kbar level. Moreover, the formation of SynGAP/PSD-95 droplets is a very rapid process that can be switched on and off in seconds. In contrast with the marked effects of the cosolutes on droplet stability, at the cosolutes' respective biologically relevant concentrations, their impact on the phase transformation kinetics is rather small. Only a high TMAO concentration results in a significant kinetic retardation of LLPS. Taken together, these findings offer new biophysical insights into the neurological effects of hydrostatic pressure. In particular, our results indicate how pressure-induced neurological disorders might be alleviated by upregulating certain cosolutes in the cellular milieu.

Gonad somatic cells acquire sex-specific fates during sex determination. In XX gonad, a subset of somatic cells expresses Foxl2 after sex determination which is considered the progenitor of granulosa cells. However, whether these cells also contribute to other cell types at later developmental stages is unknown. In the present study, the cell fate of Foxl2-expressing cells in fetal ovaries was analyzed by lineage tracing and single-cell transcriptomics. We found that Foxl2-expressing cells gave rise to three cell types at later developmental stages, including granulosa cells, theca-interstitial cells, and stromal cells. Series single-cell RNA sequencing revealed FOXL2-positive cells were divided into two clusters at P0. One group further differentiated into granulosa cells and Theca-G (Theca-interstitial cells derived from granulosa) at P14. Another group was classified as stromal cell lineage, then a small portion of them further differentiated into 3β-HSD-positive Theca-S (Theca-interstitial cells derived from stroma). Cyp17a1 was expressed in Theca-S, but not in Theca-G. This study demonstrated that Folx2-expressing cells in XX gonad after sex determination are multipotent and theca-interstitial cells are derived from different progenitors. Our data provided an important resource, at single-cell resolution, for a better understanding of somatic cell differentiation in ovary development.

Protein arginine methyltransferase 5 (Prmt5) is the major type II enzyme responsible for symmetric dimethylation of arginine. Here, we found that PRMT5 was expressed at high level in ovarian granulosa cells of growing follicles. Inactivation of Prmt5 in granulosa cells resulted in aberrant follicle development and female infertility. In Prmt5-knockout mice, follicle development was arrested with disorganized granulosa cells in which WT1 expression was dramatically reduced and the expression of steroidogenesis-related genes was significantly increased. The premature differentiated granulosa cells were detached from oocytes and follicle structure was disrupted. Mechanism studies revealed that Wt1 expression was regulated by PRMT5 at the protein level. PRMT5 facilitated IRES-dependent translation of Wt1 mRNA by methylating HnRNPA1. Moreover, the upregulation of steroidogenic genes in Prmt5-deficient granulosa cells was repressed by Wt1 overexpression. These results demonstrate that PRMT5 participates in granulosa cell lineage maintenance by inducing Wt1 expression. Our study uncovers a new role of post-translational arginine methylation in granulosa cell differentiation and follicle development., eLife digest Infertility in women can be caused by many factors, such as defects in the ovaries. An important part of the ovaries for fertility are internal structures called follicles, which house early forms of egg cells. A follicle grows and develops until the egg is finally released from the ovary into the fallopian tube, where the egg can then be fertilised. In the follicle, an egg is surrounded by other types of cells, such as granulosa cells. The egg and neighbouring cells must maintain healthy contacts with each other, otherwise the follicle can stop growing and developing, potentially causing infertility. The development of a follicle depends on an array of proteins. For example, the transcription factor WT1 controls protein levels by activating other genes and their proteins and is produced in high numbers by granulosa cells at the beginning of follicle development. Although WT1 levels dip towards the later stages of follicle development, insufficient levels can lead to defects. So far, it has been unclear how levels of WT1in granulose cells are regulated. Chen, Dong et al. studied mouse follicles to reveal more about the role of WT1 in follicle development. The researchers measured protein levels in mouse granulosa cells as the follicles developed, and discovered elevated levels of PRMT5, a protein needed for egg cells to form and survive in the follicles. Blocking granulosa cells from producing PRMT5 led to abnormal follicles and infertility in mice. Moreover, mice that had been engineered to lack PRMT5 developed abnormal follicles, where the egg and surrounding granulosa cells were not attached to each other, and the granulosa cells had low levels of WT1. Further experiments revealed that PRMT5 controlled WT1 levels by adding small molecules called methyl groups to another regulatory protein called HnRNPA1. The addition of methyl groups to genes or their proteins is an important modification that takes place in many processes within a cell. Chen, Dong et al. reveal that this activity also plays a key role in maintaining healthy follicle development in mice, and that PRMT5 is necessary for controlling WT1. Identifying all of the intricate mechanism involved in regulating follicle development is important for finding ways to combat infertility.

This work investigates the proactive eavesdropping through a friendly full-duplex (FD) relay and a legitimate monitor over the wireless-powered suspicious communication network, where one suspect source performs energy harvesting (EH) from one dedicated power beacon and then communicates with one suspect destination. Under this setup, a relay-aided proactive eavesdropping scheme is designed to improve the surveillance performance of the system. The closed-form expressions are derived under linear and nonlinear EH models, including the decoding outage probability for the suspicious link, the eavesdropping outage probability for the eavesdropping link, and the average eavesdropping rate (AER). Based on these obtained expressions, an optimization problem to maximize the AER is formulated by jointly optimizing the power and location of the relay. The existence of the optimal solution is carefully analyzed. Moreover, the separate optimization issues of the power and location are first established, and then a bisection-based searching algorithm is presented for the joint optimization problem with the linear EH model. Furthermore, to reduce the complexity of joint optimization, a low-complexity learning-based iteration algorithm is further proposed by employing the well-fitting characteristic of the deep feedforward neural network. Numerical results verify the effectiveness of the proposed algorithm, and show that the optimized FD relay-aided proactive eavesdropping scheme outperforms the reference schemes. Finally, the application scenarios of the proposed proactive eavesdropping scheme are discussed.

Due to the widespread use of Android devices and apps, it is important to develop tools and techniques to improve app quality and performance. Our work focuses on a problem related to hardware sensors on Android devices: the failure to disable unneeded sensors, which leads to sensor leaks and thus battery drain. We propose the Sentinel testing tool to uncover such leaks. The tool performs static analysis of app code and produces a model which maps GUI events to callback methods that affect sensor behavior. Edges in the model are labeled with symbols representing the acquiring/releasing of sensors and the opening/closing of UI windows. The model is traversed to identify paths that are likely to exhibit sensor leaks during run-time execution based on two context-free languages over the symbol alphabet. The reported paths are then used to generate test cases. The execution of each test case tracks the run-time behavior of sensors and reports observed leaks. This approach has been applied to both open-sourced and closed-sourced regular Android applications as well as watch faces for Android Wear smartwatches. Our experimental results indicate that Sentinel effectively detects sensor leaks, while focusing the testing efforts on a very small subset of possible GUI event sequences.

The issues of the physical layer security are studied, where one transmitter (Alice), one full-duplex (FD) legitimate receiver (Bob) and one multi-antenna jammer (Charlie) are considered to defend against multiple passive and non-colluding eavesdroppers (Eves), for multiple-input multiple-output wiretap channels. With the assumption that the complete channel state information (CSI) for main channels and the statistical CSI for Eves' channels are available, an improved secrecy transmission design is proposed to minimise the secrecy outage probability (SOP), under the minimum secrecy rate requirement. In addition to integrating artificial noise aided transmit beamforming and multi-antenna cooperative jammer to impair Eves' channels, which is widely used in many existing works, a FD legitimate receiver is applied together to further enhance physical layer security. Based on the basic probability theory and convex optimisation, the accurate closed-form expression of the SOP is derived, and the impacts on secrecy performance are described, including the qualities of main channels, the Alice's transmit power and the number of Eves. Numerical results show that the proposed scheme using the FD Bob can significantly enhance the system security, as compared with that employing the half-duplex Bob.

Water is an important resource for crop production; identifying the spatial pattern of the crop water footprint (WF) is of great significance for the optimization of water resource consumption and management in agricultural production. This study quantified the green, blue and grey water footprints (GWF, BWF and GRWF) and water consumption (GWC, BWC and GRWC) of rice, maize and soybean at the 1 km grid level and city level in Northeast China in 2019 based on the CROPWAT 8.0 model. The results showed that the average total water footprints of rice (TWFr), maize (TWFm) and soybean (TWFs) were 624.31 m3·ton−1, 527.26 m3·ton−1 and 1298.21 m3·ton−1, respectively. The spatial differences in the WF of each crop were obvious in Northeast China, with the highest values of TWFr mainly occurring in Baicheng, Dalian and Qitaihe; the highest TWFm values were mainly found in Baicheng, Yingkou and Hulundao, and the highest TWFs were mainly found in Baicheng, Chifeng and Tongliao. The total water consumption of all three crops (TWCc) in Northeast China was 94 billion m3·yr−1 (42% green, 26% blue and 32% grey), in which the total water consumption of maize production (TWCm) accounted for 60%. The production of rice, maize and soybean in Northeast China mainly depends on green water, grey water and blue water, respectively. Combining the results of the spatial patterns of crop TWF and TWC, the study revealed that the planting pattern of crops in Northeast China was relatively reasonable for sustainable water use. Meanwhile, cities that have the potential to enhance crop production and cities that should improve their water use efficiency and reduce fertilizer application were also identified.

The cartridge filter (CF) as a "firewall" is crucial between pretreatment and nanofiltration (NF) units, but CF fouling with risk has received limited attention. The systematic autopsy for CFs (CF

Simultaneous wireless information and power transfer (SWIPT) is a promising technique for energy-constrained wireless networks. To improve the security of SWIPT-enabled relay networks, in this paper, a full-duplex (FD) destinationaided jamming strategy is proposed, where a power splitting (PS) scheme is considered and two transmission phases are designed. In the first phase, the energy-limited half-duplex relay receives the signal superposed by confidential information and artificial noise (AN) from the source and destination, respectively. And then the FD destination transmits AN to the passive eavesdropper and receives the signal from the relay concurrently in the second phase. To maximize the secrecy capacity (SC), the individual optimizations of the PS ratio and power allocation (PA) coefficient are investigated, and the approximate optimal closed-form solutions of PS and PA ratios are derived. Besides, an iterative algorithm is also proposed to obtain the global optimal SC by updating the PS and PA ratios alternately. Simulation results confirm that the theoretical PS and PA ratios coincide closely with the exact results, and demonstrate that the optimal SC obtained by the iterative algorithm matches well with that given by the exhaustive search.

Arginine methylation is one of the most important post-translational modifications which is catalyzed by protein arginine methyltransferases (PRMTs). Previous studies have demonstrated that Prmt5 plays important role in germ cell development. Prmt7 is the only family member responsible for mono-methylation of arginine residue. However, whether Prmt7 is also involved in germ cell development remains unclear. In this study, we find that PRMT7 is abundantly expressed in the male germ cells during embryonic stage (from E10.5). Depletion of Prmt7 results in the defect of germ cell proliferation during embryonic stage and the number of primordial germ cells is significantly reduced in Prmt7-/- mice at E11.5. We also find that the size of testes is reduced in Prmt7-/- mice at P5 with reduced germ cell number and the diameter of seminiferous tubules. Further study reveals that the expression of BMPs and TGF-β singling pathway is significantly changed in germ cells of Prmt7-/- mice at E12.5. However, no defect of testes development is observed in adult Prmt7-/flox; Mvh-Cre mice. Collectively, this study demonstrates that Prmt7 plays roles in male germ cell proliferation during embryonic stages and it is not required for germ cell development postnatally.

Ca(2+)/calmodulin-dependent kinase IIα (CaMKIIα) is essential for synaptic plasticity and learning by decoding synaptic Ca(2+) oscillations. Despite decades of extensive research, new mechanisms underlying CaMKIIα’s function in synapses are still being discovered. Here, we discover that Shank3 is a specific binding partner for autoinhibited CaMKIIα. We demonstrate that Shank3 and GluN2B, via combined actions of Ca(2+) and phosphatases, reciprocally bind to CaMKIIα. Under basal condition, CaMKIIα is recruited to the Shank3 subcompartment of postsynaptic density (PSD) via phase separation. Rise of Ca(2+) concentration induces GluN2B-mediated recruitment of active CaMKIIα and formation of the CaMKIIα/GluN2B/PSD-95 condensates, which are autonomously dispersed upon Ca(2+) removal. Protein phosphatases control the Ca(2+)-dependent shuttling of CaMKIIα between the two PSD subcompartments and PSD condensate formation. Activation of CaMKIIα further enlarges the PSD assembly and induces structural LTP. Thus, Ca(2+)-induced and phosphatase-checked shuttling of CaMKIIα between distinct PSD nano-domains can regulate phase separation-mediated PSD assembly and synaptic plasticity.

Continuous phase modulation (CPM) is a promising modulation scheme, due to its constant envelope and compact spectrum. However, the application of CPM is limited by the demodulation and the strict requirements of synchronization. A novel method based on the convolution neural network (CNN) is proposed for binary partial response CPM signals, where the structure of the neural network is designed according to the traditional demodulation processing. Specifically, the convolution kernels are applied to extract the high-dimensional features, which are different from the branch metrics calculated by the matched filters and phase rotation. And then the extracted features are mapped in the fully-connected layers, which plays the same role as the Viterbi decoder. Besides, the moving step of the convolution kernels is small, so that the extracted features can obtain more information than the branch metrics, even though there are some timing errors. Our numerical evaluations demonstrate that the performance of the proposed method approaches that of the theoretical optimal method. Moreover, the designed network is robust to normalized timing variance with no extra training.

The in-phase/quadrature (I/Q) branches imbalance leads to mirror subcarrier interference and worsens the performance of zero-intermediate frequency (zero-IF)-based orthogonal frequency division multiplexing (OFDM) systems. To tackle the signal detection issue of in-phase/quadrature imbalance (IQI) at the transceiver, a deep learning-based approach is proposed by using the convolutional neural network. Specifically, the network model and parameters are well-designed based on the features of the channel impulse response and the mirror interference of IQI. To verify the designed model, it is first trained by simulated data under the off-line training and then used directly to recover the on-line transmitted data. The simulation results demonstrate that the proposed method shows excellent performance in processing OFDM signals under the case of IQI and it is more robust than traditional methods even without cyclic prefix.

This work investigates a relay-aided proactive eavesdropping network, where a legitimate monitor eavesdrops on communication between suspicious users via a friendly amplify-and-forward full-duplex (FD) relay. The closed-form expressions are derived, including the decoding outage probability for the suspicious link, the eavesdropping non-outage probability for the eavesdropping link, and the average eavesdropping rate (AER). To maximize the AER, separate optimization problems for the power and location of the relay are settled, employing the good fitting characteristic of the deep feedforward neural network. Then, a low-complexity learning-based iteration algorithm is proposed to solve the joint optimization problem. Numerical results demonstrate the effectiveness and optimality of the proposed algorithm, and show that the optimized FD relay-aided proactive eavesdropping scheme outperforms the existing benchmark schemes in terms of the AER.

This paper studies a legitimate proactive eavesdropping scenario where a central monitor covertly wiretaps the communications between suspicious users through a full-duplex multi-antenna relay. Specifically, the suspicious information is intercepted by the eavesdropping relay, and then encoded and forwarded to the central monitor. At the same time, the relay sends jamming signals to the suspect destination to reduce the quality of suspicious communication. To minimize the suspicious secrecy rate, the optimal forwarding and jamming beamforming vectors of the eavesdropping relay are first designed. Based on this optimized result, the best power allocation ratio is obtained. To this end, the optimal beamforming vectors and power allocation ratio are derived in closed-form. The simulation results verify the existence of the optimal forwarding power of the relay and show that the proposed scheme achieves better performance than the conventional schemes.

Legitimate wireless surveillance plays an important and preventive role in protecting public safety. To promote the eavesdropping performance of wireless surveillance systems, a proactive eavesdropping scheme with a decode-and-forward relay is proposed, where the relay intercepts suspicious information and interferes with the suspicious receiver simultaneously. The closed-form expressions are derived, including the decoding outage probability, eavesdropping outage probability, and average eavesdropping rate. To maximize the average eavesdropping rate, the transmit power and location deployment at the relay are optimized. Specifically, the closed-form result of approximate optimal transmit power for the relay is obtained, and the bisection-based algorithm is further proposed to verify its correctness. Simulation results validate that the proposed scheme achieves better eavesdropping performance than that without optimization.

Advanced oxidation processes (AOPs) are effective ways to degrade refractory organic contaminants, relying on the generation of inorganic radicals (e.g., &bull, OH and SO4&bull, &minus, ). Herein, a novel AOP with organic radicals (R-O&bull, ) was reported to degrade contaminants. Lanthanum cobaltite perovskite (LaCoO3) was used to activate peracetic acid (PAA) for organic radical generation to degrade sulfamethoxazole (SMX). The results show that LaCoO3 exhibited an excellent performance on PAA activation and SMX degradation at neutral pH, with low cobalt leaching. Meanwhile, LaCoO3 also showed an excellent reusability during PAA activation. In-depth investigation confirmed CH3C(O)O&bull, and CH3C(O)OO&bull, as the key reactive species for SMX degradation in LaCoO3/PAA system. The presence of Cl&minus, (1&ndash, 100 mM) slightly inhibited the degradation of SMX in the LaCoO3/PAA system, whereas the addition of HCO3&minus, (0.1&ndash, 1 mM) and humic aid (1&ndash, 10 mg/L) could significantly inhibit SMX degradation. This work highlights the generation of organic radicals via the heterogeneous activation of PAA and thus provides a promising way to destruct contaminants in wastewater treatment.

In this article, the three-dimensional trajectory tracking control of an autonomous underwater vehicle is addressed. The vehicle is assumed to be underactuated and the system parameters and the external disturbances are unknown. First, the five degrees of freedom kinematics and dynamics model of underactuated autonomous underwater vehicle are acquired. Following this, reduced-order linear extended state observers are designed to estimate and compensate for the uncertainties that exist in the model and the external disturbances. A backstepping active disturbance rejection control method is designed with the help of a time-varying barrier Lyapunov function to constrain the position tracking error. Furthermore, the controller system can be proved to be stable by employing the Lyapunov stability theory. Finally, the simulation and comparative analyses demonstrate the usefulness and robustness of the proposed controller in the presence of internal parameter uncertainties and external time-varying disturbances.

Correction for ‘Chemical structure modulation in conductive MOFs by adjusting the oxidation state of the ligand and introducing alkali metal ions’ by Xiaoyu Wu et al., Chem. Commun., 2022, 58, 2702–2705, DOI: 10.1039/D1CC06407J.

As an emerging light source, ultraviolet light emitting diodes (UV-LEDs) are adopted to overcome the shortcomings of the conventional mercury lamp, such as mercury pollution. The degradation of chloramphenicol (CAP) using three UV-LED-based advanced oxidation processes (AOPs)—UV-LED/persulfate (UV-LED/PS), UV-LED/peroxymonosulfate (UV-LED/PMS) and UV-LED/chlorine—was investigated. Results indicate that CAP can be more effectively degraded by the hybrid processes when compared to UV irradiation and oxidants alone. Degradation of CAP using the three UV-LED-based AOPs followed pseudo-first-order kinetics. The degradation rate constants (kobs) for UV-LED/PS, UV-LED/PMS, and UV-LED/chlorine were 0.0522, 0.0437 and 0.0523 min−1, and the CAP removal rates 99%, 98.1% and 96.3%, respectively. The degradation rate constant (kobs) increased with increasing oxidant dosage for UV-LED/chlorine, whereas overdosing reduced CAP degradation using UV-LED/PS and UV-LED/PMS. Ultraviolet wavelength influenced degradation efficiency of the UV-LED based AOPs with maximum CAP degradation observed at a wavelength of 280 nm. The application of UV-LED enhanced the formation DBPs during subsequent chlorination. uUV-LED/PMS produced more disinfection by-products than UV-LED/PS. Compared to UV-LED, UV-LED/PS reduced the formation of dichloroacetonitrile and trichloronitromethane during chlorination owing to its capacity to degrade the nitro group in CAP. The intermediates dichloroacetamide, 4-nitrobenzoic acid, 4-nitrophenol were produced during the degradation of CAP using each of UV-LED, UV-LED/PS and UV-LED/chlorine. The present study provides further evidence supporting the application of UV-LED in AOPs.

In this paper, a turning circle based trajectory planning method (TCBTPM) is proposed to conduct trajectory planning of an underactuated autonomous underwater vehicle (AUV) for mobile docking mission. Firstly, the six degrees of freedom kinematics and dynamics model of underactuated AUV is acquired. Following this, the simulation of horizontal turning circle trial is studied and the overview of mobile docking mission is introduced. Furthermore, TCBTPM is used to predict the relative position of AUV and the mobile docking station (MDS) in advance and generate a feasible trajectory for the mobile docking mission. Finally, a mobile docking guidance system containing TCBTPM, pure pursuit (PP) guidance law and line-of-sight (LOS) guidance law is employed to obtain desired guidance commands and guides the underactuated AUV to dock efficiently and reliably.

In this paper, the joint communication and computation resource allocation problem for a single cell massive MIMO based mobile edge computing (MEC) network is discussed. In particular, we study the joint optimization of the pilot transmission power, data transmission power and the computing resource at the MEC server with the target of minimizing the maximal offloading delay over multiple users. Due to the non-convexity of the formulated problem and the defined optimal solution conditions, two suboptimal algorithms, i.e., the external point iteration and gradient descent based penalty function algorithm (EPF-GDA) and the external penalty function iteration based fruit fly optimization algorithm (EPF-FOA), are proposed to obtain the suboptimal solutions. The performance of the proposed algorithms, such as the users’ offloading delay, is verified by numerical simulations. And our results confirm the great performance gain of the algorithm EPF-FOA over EPF-GDA under different circumstances.

The interaction between germ cell and somatic cell plays important roles in germ cell development. However, the exact function of gonad somatic cell in germ cell differentiation is unclear. In the present study, the function of gonad somatic cell in germ cell meiosis was examined by using mouse models with aberrant somatic cell differentiation. In Wt1R394W/R394W mice, the genital ridge is absent due to the apoptosis of coelomic epithelial cells. Interestingly, in both male and female Wt1R394W/R394W germ cells, STRA8 was detected at E12.5 and the scattered SYCP3 foci were observed at E13.5 which was consistent with control females. In Wt1-/flox; Cre-ERTM mice, Wt1 was inactivated by the injection of tamoxifen at E9.5 and the differentiation of Sertoli and granulosa cells was completely blocked. We found that most germ cells were located outside of genital ridge after Wt1 inactivation. STRA8, SYCP3, and γH2AX proteins were detected in germ cells of both male and female Wt1-/flox; Cre-ERTM gonads, whereas no thread-like SYCP3 signal was observed. Our study demonstrates that aberrant development of gonad somatic cells leads to ectopic expression of meiosis-associated genes in germ cells, but meiosis was arrested before prophase I. These results suggest that the proper differentiation of gonad somatic cells is essential for germ cell meiosis.

Emerging evidence indicates that liquid-liquid phase separation, the formation of a condensed molecular assembly within another diluted aqueous solution, is a means for cells to organize highly condensed biological assemblies (also known as biological condensates or membraneless compartments) with very broad functions and regulatory properties in different subcellular regions. Molecular machineries dictating synaptic transmissions in both presynaptic boutons and postsynaptic densities of neuronal synapses may be such biological condensates. Here we review recent developments showing how phase separation can build dense synaptic molecular clusters, highlight unique features of such condensed clusters in the context of synaptic development and signaling, discuss how aberrant phase-separation-mediated synaptic assembly formation may contribute to dysfunctional signaling in psychiatric disorders, and present some challenges and opportunities of phase separation in synaptic biology.

A novel tri-band bandpass filter (BPF) based on ring multi-mode resonator (R-MMR) is proposed in this paper. The filter consists of an R-MMR and a pair of parallel coupled lines. Because the R-MMR is symmetrical, its resonant characteristics can be analyzed by using odd- and even-mode analysis method. When a couple of stubs are loaded on the ring resonator, six transmission poles and four transmission zeros are created, and a tri-band BPF is realized by employing a couple of parallel coupled lines. To miniaturize the size, the R-MMR is folded. A prototype is designed, fabricated and measured. Good agreement is obtained between the simulated and measured results.

The rice field eel Monopterus albus is a hermaphroditic protogynous fish species that undergoes sex reversal from female to male. However, the potential mechanisms underlying the process of sex transformation are still unclear. We analyzed and compared the gene sequence of M. albus dmrt1 5′ upstream region and its potential transcription factor binding sites with other known species and examined the in vitro effects of testosterone (T) on the expression levels of dmrt1a and foxl2 in the ovotestis. Moreover, we cloned and analyzed the expression of genes encoding enzymes, 11β-hydroxylase (11β-h) and 11β-hydroxysteroid dehydrogenase (11β-hsd), involved in the production of 11-ketotestosterone (11-KT). The results showed that, compared with other fish species, M. albus dmrt1 5′ upstream region contained unique androgen response elements (AREs) with one on the sense strand and the other one on the antisense strand, indicating a crucial role for androgens in the transcriptional regulation of dmrt1. The expression of dmrt1a was induced but the expression of foxl2 was inhibited by T manipulation in vitro, suggesting that blood androgen could activate the transcription of dmrt1 in the ovotestis. Moreover, the expression levels of 11β-h and 11β-hsd2 were predominantly expressed in testis, much less in ovotestis, and barely in ovary, suggesting the production of 11-KT during sex reversal. Androgens are synthesized in large amounts during sex reversal, leading to the promotion of dmrt1 transcription, and thus, gonadal somatic cells transdifferetiation. Overall, androgen-dmrt1 positive feedback programs the M. albus sex reversal.

Bulk high-temperature superconductors exhibit outstanding electromagnetic properties and are capable of trapping very large magnetic fields. However, bulk superconductors are subjected to a large Lorentz force during field cooling magnetization (FCM), which can cause crack initiation and propagation. Superconducting performance is then limited by the damage to the bulk. In this paper, we study the mechanical behavior and brittle damage of a three-dimensional (3D) bulk GdBCO superconductor during FCM. Firstly, the distribution of electromagnetic field in the bulk is obtained based on the H-formulation with a finite element model. Then, a 3D bond-based peridynamic (PD) model is used to simulate the mechanical behavior and possible brittle damage to the bulk under a given electromagnetic force. The initiation and propagation of cracks can be predicted using the 3D bond-based PD model. The effect of residual stress due to the presence of a reinforcement ring during the cooling process is also discussed. The results show that mechanical stability can be improved by reinforcing the sample.

Two key unsolved problems faced by frequency-modulated continuous-wave (FMCW) synthetic aperture radar (SAR), namely, spatial-variant linear range cell migration (RCM) and range frequency aliasing in a traditional frequency scaling (FS) algorithm, are mitigated in this paper. For FMCW-SAR platform, it usually operates at low altitude space for which the squint angle is range dependent. This range-dependent squint angle in return causes serious spatial-variant linear RCM that deteriorates image quality if it is not properly handled. To focus squint FMCW-SAR, FS is normally utilized. This operation, however, creates an issue, range frequency aliasing that needs to be addressed as well. To overcome these two problems, in this paper, based on the modified inverse Chirp-Z transform (ICZT) and series inversion, a novel imaging algorithm performing the spatial-variant linear RCM correction and eliminating the range frequency aliasing for focusing squint FMCW-SAR is proposed. First, the influences of the range-dependent squint angle on imaging quality are analyzed. Based on the obtained analysis result, a new scaling factor containing the linear RCM spatial variance correction is designed, and then, an efficient modified ICZT is developed to remove the range-dependent RCM and frequency aliasing. As a result, the well-focused SAR image is produced. The proposed method can be efficiently implemented, since it only requires fast Fourier transform and no interpolation is demanded. Finally, the experimental results with simulated data demonstrate the effectiveness of the proposed algorithm.

Melt-textured large, single-grain REBCO (RE: rare earth element or Y) bulk superconductors have growth sector boundaries (GSBs) and growth sector regions (GSRs). The critical current density is dependent on the GSBs and the GSRs, which will influence the electromagnetic field and the temperature field distributions. REBCO bulk superconductors are brittle materials and during the manufacturing process, cracks and inclusions may exist, therefore it is necessary to analyze the mechanical response during the magnetization process. In this paper, the mechanical response of an inhomogeneous cylinder superconductor under electromagnetic stress and the thermal stress during the pulsed field magnetization process is studied. By solving the coupled magnetic and heat diffusion equations in association with a modified E − J power-law relationship, we can obtain the electromagnetic field and the temperature field distributions; then, the mechanical response of the bulk can be determined. The trend shown by our numerical simulation is consistent with the experimental results. Then we study the mechanical behavior of inhomogeneous high-temperature superconductors with and without a flux jump. The case without or with the SUS 304 ring is also analyzed.