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Wireless underground sensor networks (WUSNs) promise to deliver substantial social and economic benefits across different verticals. However, many of the relevant application scenarios are located in remote areas with no supporting infrastructure available. To address this challenge, we conceptualize in this study the underground direct-to-satellite (U-DtS) connectivity approach, implying the reception of the signals sent by the underground massive machine-type communication (mMTC) sensors by the gateways operating on the low Earth orbit satellites. We start by discussing the two alternative architectures for enabling such networks and underline their features and limitations. Then, we employ simulations to model a smart-farming application scenario for studying the feasibility and performance of UDtS mMTC based on LoRaWAN technology, with the focus on the effect of the parameters including the burial depths, soils characteristics, and communication settings. Our results reveal that the LoRa modulation fails to compete with the underground propagation losses and the high packets collision rate. However, the long range-frequency hopping spread spectrum (LR-FHSS) modulation is perspective for U-DtS networks and may enable connectivity for the subsurface nodes located at a depth of several dozens centimeters. Finally, we pinpoint the potential challenges and the research directions for future U-DtS studies.

Radio-frequency wireless energy transfer (WET) is a promising technology to realize wireless-powered underground sensor networks (WPUSNs) and enable sustainable underground monitoring. However, due to the severe attenuation in harsh underground soil and the tight energy budget of the underground sensors, traditional WPUSNs relying on the channel state information (CSI) are highly inefficient, especially in massive WET scenarios. To address this challenge, we comparatively assess the feasibility of several state-of-the-art CSI-free multiantenna WET schemes for WPUSNs, under a given power budget. Moreover, to overcome the extremely low WET efficiency in underground channels, we propose a distributed CSI-free system, where multiple power beacons (PBs) simultaneously charge a large set of underground sensors without any CSI. We consider the position-aware K -Means and the position-agnostic equally far-from-center (EFFC) approaches for the optimal deployment of the PBs. Our results evince that the performance of the proposed distributed CSI-free system can approach or even surpass that of a traditional full-CSI WET strategy, especially when adopting an appropriate CSI-free scheme, applying the advisable PBs deployment approach, and equipping the PBs with an appropriate number of antennas. Finally, we discuss the impact of underground parameters, i.e., the burial depth of devices and the volumetric water content of soil, on the system’s performance, and identify potential challenges and research opportunities for practical distributed CSI-free WPUSNs deployment.

Background: Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) disproportionately affect men who have sex with men (MSM). Data on the prevalence, anatomical distribution, and correlates of NG and CT infections among MSM in Vietnam are limited.Methods: Between July 2017 and April 2019, MSM 16 years or older, without HIV were enrolled into an observational cohort study. Baseline data, including sociodemographics, sexual behavior, and HIV status were collected. NG and CT testing were performed on urine, rectal, and pharyngeal specimens. Multivariate logistic regression models identified factors associated with NG and CT infections at baseline.Results: In total, 1489 participants underwent NG/CT testing. The median age was 22 years (IQR: 20 – 26). There were 424 (28.5%) NG or CT infections; 322 (21.6%) with CT and 173 (11.6%) with NG. Rectal infections were most common for CT (73.9%), while pharyngeal infections were most common for NG (70.5%). Independent risk factors for CT or NG infection included: ≥2 sex partners in the prior month (adjusted odds ratio [aOR] = 2.04; 95% CI: 1.44, 2.91), condomless anal sex (aOR = 1.44, 95% CI: 1.12, 1.86), and meeting sex partners online (aOR = 1.35; 95% CI: 1.03, 1.76). Recent genitourinary or rectal symptoms were not associated with infections.Conclusions: The overall and extragenital prevalence of NG and CT infections were high within this sample of young MSM without HIV in Hanoi. Testing limited to urethral specimens would have missed nearly three-quarters of CT and NG infections, supporting the need for routine testing at multiple anatomic sites.

Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) disproportionately affect men who have sex with men (MSM). Data on the prevalence, anatomical distribution, and correlates of NG and CT infections among MSM in Vietnam are limited.Between July 2017 and April 2019, MSM 16 years or older, without HIV were enrolled into an observational cohort study. Baseline data, including sociodemographics, sexual behavior, and HIV status were collected. NG and CT testing were performed on urine, rectal, and pharyngeal specimens. Multivariate logistic regression models identified factors associated with NG and CT infections at baseline.In total, 1489 participants underwent NG/CT testing. The median age was 22 years (IQR: 20 - 26). There were 424 (28.5%) NG or CT infections; 322 (21.6%) with CT and 173 (11.6%) with NG. Rectal infections were most common for CT (73.9%), while pharyngeal infections were most common for NG (70.5%). Independent risk factors for CT or NG infection included: ≥2 sex partners in the prior month (adjusted odds ratio [aOR] = 2.04; 95% CI: 1.44, 2.91), condomless anal sex (aOR = 1.44, 95% CI: 1.12, 1.86), and meeting sex partners online (aOR = 1.35; 95% CI: 1.03, 1.76). Recent genitourinary or rectal symptoms were not associated with infections.The overall and extragenital prevalence of NG and CT infections were high within this sample of young MSM without HIV in Hanoi. Testing limited to urethral specimens would have missed nearly three-quarters of CT and NG infections, supporting the need for routine testing at multiple anatomic sites.

Background: Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) disproportionately affect men who have sex with men (MSM). Data on the prevalence, anatomical distribution, and correlates of NG and CT infections among MSM in Vietnam are limited.Methods: Between July 2017 and April 2019, MSM 16 years or older, without HIV were enrolled into an observational cohort study. Baseline data, including sociodemographics, sexual behavior, and HIV status were collected. NG and CT testing were performed on urine, rectal, and pharyngeal specimens. Multivariate logistic regression models identified factors associated with NG and CT infections at baseline.Results: In total, 1489 participants underwent NG/CT testing. The median age was 22 years (IQR: 20 – 26). There were 424 (28.5%) NG or CT infections; 322 (21.6%) with CT and 173 (11.6%) with NG. Rectal infections were most common for CT (73.9%), while pharyngeal infections were most common for NG (70.5%). Independent risk factors for CT or NG infection included: ≥2 sex partners in the prior month (adjusted odds ratio [aOR] = 2.04; 95% CI: 1.44, 2.91), condomless anal sex (aOR = 1.44, 95% CI: 1.12, 1.86), and meeting sex partners online (aOR = 1.35; 95% CI: 1.03, 1.76). Recent genitourinary or rectal symptoms were not associated with infections.Conclusions: The overall and extragenital prevalence of NG and CT infections were high within this sample of young MSM without HIV in Hanoi. Testing limited to urethral specimens would have missed nearly three-quarters of CT and NG infections, supporting the need for routine testing at multiple anatomic sites.

Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) disproportionately affect men who have sex with men (MSM). Data on the prevalence, anatomical distribution, and correlates of NG and CT infections among MSM in Vietnam are limited.Between July 2017 and April 2019, MSM 16 years or older, without HIV were enrolled into an observational cohort study. Baseline data, including sociodemographics, sexual behavior, and HIV status were collected. NG and CT testing were performed on urine, rectal, and pharyngeal specimens. Multivariate logistic regression models identified factors associated with NG and CT infections at baseline.In total, 1489 participants underwent NG/CT testing. The median age was 22 years (IQR: 20 - 26). There were 424 (28.5%) NG or CT infections; 322 (21.6%) with CT and 173 (11.6%) with NG. Rectal infections were most common for CT (73.9%), while pharyngeal infections were most common for NG (70.5%). Independent risk factors for CT or NG infection included: ≥2 sex partners in the prior month (adjusted odds ratio [aOR] = 2.04; 95% CI: 1.44, 2.91), condomless anal sex (aOR = 1.44, 95% CI: 1.12, 1.86), and meeting sex partners online (aOR = 1.35; 95% CI: 1.03, 1.76). Recent genitourinary or rectal symptoms were not associated with infections.The overall and extragenital prevalence of NG and CT infections were high within this sample of young MSM without HIV in Hanoi. Testing limited to urethral specimens would have missed nearly three-quarters of CT and NG infections, supporting the need for routine testing at multiple anatomic sites.

Considering the large volumes of treated water and incomplete elimination of pollutants, wastewater treatment plants (WWTPs) remain a considerable source of microplastics (MPs). Chlorine, the most frequently used disinfectant in WWTPs, has a strong oxidizing impact on MPs. However, little is documented, to date, about the impact of chlorination on the transformation of MPs and the subsequent environmental behaviors of the chlorinated MPs when released into the aquatic environment. This study explored the response of the physicochemical properties of specific thermoplastics, namely polyurethane (TPU) MPs and polystyrene (PS) MPs, to chlorination and their emerging pollutant [tetracycline (TC)] adsorption behavior in aqueous solution. The results indicated that the O/C ratio of the MP surface did not significantly change, and that there were increases in the O-containing functional groups of the TPU and PS MPs, after chlorination. The surface area of the chlorinated TPU MPs increased by 45 %, and that of the chlorinated PS increased by 21 %, compared with the pristine ones, which contributed to the TC adsorption. The adsorption isotherm fitting parameters suggested that the chlorinated TPU fitted the multilayer adsorption, and the chlorinated PS was inclined to the monolayer adsorption. The relative abundance of the O-containing functional groups, on the TPU surface, led to the release of CHCl3 molecules, and the clear surface irregularities and fissures occurred after chlorine treatment. No fissures were found on the surface of the chlorinated PS MPs. The hydrophobicity and electrostatic adsorption were proved to be the major impacts on the TC adsorption of the chlorinated MPs, and the subsequently formed hydrogen bonds led to the stronger adsorption capacity of the chlorinated TPU than the chlorinated PS MPs.

Considering the large volumes of treated water and incomplete elimination of pollutants, wastewater treatment plants (WWTPs) remain a considerable source of microplastics (MPs). Chlorine, the most frequently used disinfectant in WWTPs, has a strong oxidizing impact on MPs. However, little is documented, to date, about the impact of chlorination on the transformation of MPs and the subsequent environmental behaviors of the chlorinated MPs when released into the aquatic environment. This study explored the response of the physicochemical properties of specific thermoplastics, namely polyurethane (TPU) MPs and polystyrene (PS) MPs, to chlorination and their emerging pollutant [tetracycline (TC)] adsorption behavior in aqueous solution. The results indicated that the O/C ratio of the MP surface did not significantly change, and that there were increases in the O-containing functional groups of the TPU and PS MPs, after chlorination. The surface area of the chlorinated TPU MPs increased by 45 %, and that of the chlorinated PS increased by 21 %, compared with the pristine ones, which contributed to the TC adsorption. The adsorption isotherm fitting parameters suggested that the chlorinated TPU fitted the multilayer adsorption, and the chlorinated PS was inclined to the monolayer adsorption. The relative abundance of the O-containing functional groups, on the TPU surface, led to the release of CHCl3 molecules, and the clear surface irregularities and fissures occurred after chlorine treatment. No fissures were found on the surface of the chlorinated PS MPs. The hydrophobicity and electrostatic adsorption were proved to be the major impacts on the TC adsorption of the chlorinated MPs, and the subsequently formed hydrogen bonds led to the stronger adsorption capacity of the chlorinated TPU than the chlorinated PS MPs.

Wireless underground sensor networks (WUSNs) using wirelessly-connected buried sensors enable smart agriculture through real-time soil sensing, timely decision-making, and precise remote operation. Energy harvesting technology is adopted in WUSNs, implying wireless-powered underground sensor networks (WPUSNs), to prolong the network lifetime. In addition, the backscatter communication (BSC) technology seems promising for improving the utilization of resources and network throughput according to preliminary studies in terrestrial wireless-powered communication networks. However, this technique has not yet been investigated in WPUSNs, where channel impairments are incredibly severe. In this work, we aim to assess BSC’s performance in WPUSNs and evaluate its feasibility for sustainable smart agriculture. For this, we first conceptualize a multi-user backscatter-assisted WPUSN (BS-WPUSN), where a set of energy-constrained underground sensors (USs) backscatter and/or harvest the radio frequency energy emitted by an above-ground power source before the sensed data are transmitted to a nearby above-ground access point. Then, we formulate the optimal time allocation to maximize the network throughput while assuring real-world users’ quality of service (QoS). Our analysis considers the non-linearities of practical energy harvesting circuits and severe signal attenuation in underground channels. By simulating a realistic farming scenario, we show that our proposed solution outperforms two baseline schemes, i.e., underground harvest-then-transmit and underground BSC, by an average of 12% and 358% increase in network throughput (when USs are buried at 0.35 m), respectively. Additionally, several trade-offs between the network throughput, time allocation, network configurations, and underground parameters are identified to facilitate the practical implementation of BS-WPUSNs.

Atmospheric nitrogen (N) deposition, climatic variables and anthropogenic management affect grassland-ecosystem stability by driving changes in plant community and loss of plant diversity. Determination of their influences on plant composition and diversity is essential for predicting ecosystem response to future global changes and for making policies of sustainable grassland management. We evaluated the relative contributions of atmospheric N deposition, climatic variables and grassland management to plant diversity and N accumulation by temporally monitoring the changes in plant community and N status in a temperate grassland ecosystem. Ambient low-level N deposition combined with long-term grassland enclosure led to increases in above-ground biomass and abundance of grasses and sedges, and decreases in those of forbs. The dominant species of perennial forbs and grasses also displayed divergence in their biomass and abundance over time. Nitrogen deposition made greater contributions to the divergent changes in perennial forbs and grasses. However, air temperature and precipitation fluctuations mainly contributed to the annual fluctuations in annual and biennial species. Long-term enclosure aggravated the cumulative effects of soil inorganic N on plant-diversity loss while mowing had opposite effects on the N accumulation. Synthesis and applications. Ambient low-level N deposition can drive loss of plant diversity due to N accumulation in grassland ecosystem under long-time enclosure. Therefore, appropriate grassland management, such as rationally grazing and/or mowing, may be effective practices in terms of maintenance of plant biodiversity under the scenario of enhanced atmospheric N deposition.

Atmospheric nitrogen (N) deposition, climatic variables and anthropogenic management affect grassland-ecosystem stability by driving changes in plant community and loss of plant diversity. Determination of their influences on plant composition and diversity is essential for predicting ecosystem response to future global changes and for making policies of sustainable grassland management. We evaluated the relative contributions of atmospheric N deposition, climatic variables and grassland management to plant diversity and N accumulation by temporally monitoring the changes in plant community and N status in a temperate grassland ecosystem. Ambient low-level N deposition combined with long-term grassland enclosure led to increases in above-ground biomass and abundance of grasses and sedges, and decreases in those of forbs. The dominant species of perennial forbs and grasses also displayed divergence in their biomass and abundance over time. Nitrogen deposition made greater contributions to the divergent changes in perennial forbs and grasses. However, air temperature and precipitation fluctuations mainly contributed to the annual fluctuations in annual and biennial species. Long-term enclosure aggravated the cumulative effects of soil inorganic N on plant-diversity loss while mowing had opposite effects on the N accumulation. Synthesis and applications. Ambient low-level N deposition can drive loss of plant diversity due to N accumulation in grassland ecosystem under long-time enclosure. Therefore, appropriate grassland management, such as rationally grazing and/or mowing, may be effective practices in terms of maintenance of plant biodiversity under the scenario of enhanced atmospheric N deposition.

Nitrogen (N) deposition can profoundly alter soil N cycling of grassland ecosystems. Substrates and soil acidification are expected to modify soil N transformations in response to elevated N deposition. Here, we carried out 15N tracing studies to test the effects of N addition rates (low: 30 kg N ha−1 and high: 90/120 kg N ha−1) and soil acidification on gross N transformation rates using two typical Chinese grassland soils, an alpine calcareous soil and a temperate neutral soil. We found that N addition significantly increased the ratio of gross nitrification rate to gross ammonia immobilization rate (N/I) in both soils, but gross N transformation rates changed differently as a function of N addition rates and soil types. In the calcareous soil, N addition increased soil gross N transformations, largely due to mineral N substrates, SOC, TN and fungal dominance. In contrast, low N addition did not affect gross N transformation rates in the neutral soil, but high N addition significantly decreased gross N transformation rates. Although both SOC and TN were increased with N addition in the neutral soil, N-induced soil pH decline decreased gross N transformation rates. Our results indicate that the effects of N addition on grassland soil gross N transformations are highly dependent on mineral N substrates, SOC and TN. Soil acidification played a more important role than SOC and TN in gross N transformation rate changes in response to elevated N deposition. These findings suggest that the different changes of gross N transformation rates in response to N deposition and soil properties (e.g. SOC, TN and soil pH) should be integrated into biogeochemical models to better predict grassland ecosystem N cycling in the future scenarios of N deposition.

Incorporating nanoscale Si into a carbon matrix with high dispersity is desirable for the preparation of lithium-ion batteries (LIBs) but remains challenging. A space-confined catalytic strategy is proposed for direct superassembly of Si nanodots within a carbon (Si NDs⊂C) framework by copyrolysis of triphenyltin hydride (TPT) and diphenylsilane (DPS), where Sn atomic clusters created from TPT pyrolysis serve as the catalyst for DPS pyrolysis and Si catalytic growth. The use of Sn atomic cluster catalysts alters the reaction pathway to avoid SiC generation and enable formation of Si NDs with reduced dimensions. A typical Si NDs⊂C framework demonstrates a remarkable comprehensive performance comparable to other Si-based high-performance half LIBs, and higher energy densities compared to commercial full LIBs, as a consequence of the high dispersity of Si NDs with low lithiation stress. Supported by mechanic simulations, this study paves the way for construction of Si/C composites suitable for applications in future energy technologies.

Weak van der Waals interactions between interlayers of two-dimensional layered materials result in disabled across-interlayer electron transfer and poor layered structural stability, seriously deteriorating their performance in energy applications. Herein, we propose a novel covalent assembly strategy for MoS2 nanosheets to realize unique MoS2 /SnS hollow superassemblies (HSs) by using SnS nanodots as covalent linkages. The covalent assembly based on all-inorganic and carbon-free concept enables effective across-interlayer electron transfer, facilitated ion diffusion kinetics, and outstanding mechanical stability, which are evidenced by experimental characterization, DFT calculations, and mechanical simulations. Consequently, the MoS2 /SnS HSs exhibit superb rate performance and long cycling stability in lithium-ion batteries, representing the best comprehensive performance in carbon-free MoS2 -based anodes to date. Moreover, the MoS2 /SnS HSs also show excellent sodium storage performance in sodium-ion batteries.

Nitrogen (N) deposition can profoundly alter soil N cycling of grassland ecosystems. Substrates and soil acidification are expected to modify soil N transformations in response to elevated N deposition. Here, we carried out 15N tracing studies to test the effects of N addition rates (low: 30 kg N ha−1 and high: 90/120 kg N ha−1) and soil acidification on gross N transformation rates using two typical Chinese grassland soils, an alpine calcareous soil and a temperate neutral soil. We found that N addition significantly increased the ratio of gross nitrification rate to gross ammonia immobilization rate (N/I) in both soils, but gross N transformation rates changed differently as a function of N addition rates and soil types. In the calcareous soil, N addition increased soil gross N transformations, largely due to mineral N substrates, SOC, TN and fungal dominance. In contrast, low N addition did not affect gross N transformation rates in the neutral soil, but high N addition significantly decreased gross N transformation rates. Although both SOC and TN were increased with N addition in the neutral soil, N-induced soil pH decline decreased gross N transformation rates. Our results indicate that the effects of N addition on grassland soil gross N transformations are highly dependent on mineral N substrates, SOC and TN. Soil acidification played a more important role than SOC and TN in gross N transformation rate changes in response to elevated N deposition. These findings suggest that the different changes of gross N transformation rates in response to N deposition and soil properties (e.g. SOC, TN and soil pH) should be integrated into biogeochemical models to better predict grassland ecosystem N cycling in the future scenarios of N deposition.

Sequencing of exomes and genomes has revealed abundant genetic variation affecting the coding sequences of human transcription factors (TFs), but the consequences of such variation remain largely unexplored. We developed a computational, structure-based approach to evaluate TF variants for their impact on DNA binding activity and used universal protein-binding microarrays to assay sequence-specific DNA binding activity across 41 reference and 117 variant alleles found in individuals of diverse ancestries and families with Mendelian diseases. We found 77 variants in 28 genes that affect DNA binding affinity or specificity and identified thousands of rare alleles likely to alter the DNA binding activity of human sequence-specific TFs. Our results suggest that most individuals have unique repertoires of TF DNA binding activities, which may contribute to phenotypic variation., National Human Genome Research Institute (U.S.) (Grant R01 HG003985)

© 2017 Author(s). In this contribution we make a short review of recent progress on topics of current interest in nuclear physics and nuclear astrophysics. In particular, we discuss a re-analysis of the extraction of the dipole response of the pigmy resonance in 68 Ni based on a continuum discretized coupled-channels calculation in relativistic Coulomb excitation experiments. We also discuss the forthcoming progresses made by our group on the Alt-Sandhas-Grassberber approach to (d,p) reactions and future expectations. The role of separable potentials in solving such equations with a test case based on applications of such potentials to phase-shift analysis is also presented.

Periodic mesoporous organosilicas (PMOs) have been synthesized through the condensation of organosilicates 1,2-bis(trimethoxysilyl) ethane around inorganic-electrolyte-stabilized Pluronic F127 [(EO)106(PO)70(EO)106] triblock copolymer micelles in a sodium bicarbonate (NaHCO3 /sodium carbonate (Na2CO3 buffer solution (pH ˜ 9 9). It is found that the addition of inorganic sulfate salts in the synthesis is crucial factor to ensure the formation of ordered mesostructures. The addition of Na2SO4 and MgSO4 in the synthesis system can lead to the formation of ordered 2-D hexagonal (P6mm) and 3-D cubic (Im3m) mesostructure, respectively. The effects of other inorganic sulfate salts such as CuSO4, NiSO4, and ZnSO4 have also been investigated. Apparently, the interaction between Pluronic F127 micelle and organosilica oligomers is enhanced by the presence of these inorganic salts. The mechanism for PMOs formation has been proposed on the basis of inorganic salts assisted micelles-organosilicates closed packing under mild synthetic condition. The findings from this work contribute fundamental understanding towards a new formation route of these ordered mesoporous materials, thus providing a new strategy to fabricate mesoporous silicas with controllable structures for emerging applications.

Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) is etiologically associated with KS, the most common AIDS-related malignancy. KS is characterized by vast angiogenesis and hyperproliferative spindle cells. We have previously reported that HIV-1 Tat can trigger KSHV reactivation and accelerate Kaposin A-induced tumorigenesis. Here, we explored Tat promotion of KSHV vIL-6-induced angiogenesis and tumorigenesis. Tat promotes vIL-6-induced cell proliferation, cellular transformation, vascular tube formation and VEGF production in culture. Tat enhances vIL-6-induced angiogenesis and tumorigenesis of fibroblasts and human endothelial cells in a chicken chorioallantoic membrane (CAM) model. In an allograft model, Tat promotes vIL-6-induced tumorigenesis and expression of CD31, CD34, SMA, VEGF, b-FGF, and cyclin D1. Mechanistic studies indicated Tat activates PI3K and AKT, and inactivates PTEN and GSK-3β in vIL-6 expressing cells. LY294002, a specific inhibitor of PI3K, effectively impaired Tat's promotion of vIL-6-induced tumorigenesis. Together, these results provide the first evidence that Tat might contribute to KS pathogenesis by synergizing with vIL-6, and identify PI3K/AKT pathway as a potential therapeutic target in AIDS-related KS patients. © 2013 Zhou et al.

QC 20100525