Study of the corrosion behavior of N80 and TP125V steels in aerobic and anoxic shale gas field produced water at high temperature.

In this study, the corrosion behavior of N80 and TP125V steels was delved firstly into produced water from shale gas fields containing CO2-O2. Moreover, the localized corrosion of these steels was investigated to elucidate the effects of aerobic and anoxic on steel corrosion. The results indicated that the corrosion rates of N80 and TP125V steels under aerobic conditions were lower compared to those in the presence of CO2-O2. Specifically, at temperature of 100 °C and with dissolved oxygen (DO) concentration of 4 mg/L in the CO2-O2 environment, the N80 and TP125V steels exhibited the highest corrosion rate, with values of 0.13 mm/y and 0.16 mm/y, respectively, as determined by specific weight loss measurements. Conversely, these rates decreased to 0.022 mm/y and 0.049 mm/y under aerobic conditions. Furthermore, severe localized corrosion of N80 and TP125V steels with a DO concentration of 4 mg/L was also observed in the CO2-O2 environment. Finally, it was evident that pitting corrosion is the predominant type of corrosion affecting N80 and TP125V steels in the produced water from shale gas fields.

An optoionic hydrogel with UV-regulated ion conductivity for reprogrammable iontronics: Logic processing and image sensing.

The development of smart hydrogels capable of actively controlling ion conductivity is of paramount importance for iontronics. Most current work in this field focuses on enhancing the hydrogels' ion conductivity. Few successes have been seen in achieving spatial regulation of ion flow through external control. Among various controls, light gives the best spatial and temporal resolution for practical iontronic applications. However, developing hydrogels that can generate drastic ion concentration change upon photoirradiation for tunable conductivity is challenging. Very few molecules can enable photoion generation, and most of them are hydrophobic and low quantum yield. Here, we present an optoionic hydrogel that uses triphenylmethane leuconitrile (TPMLN) for ultraviolet-regulated ion conductivity. Through postpolymerization TPMLN synthesizing, we can incorporate high concentration of the hydrophobic TPMLN in hydrogels without compromising the hydrogel's mechanical integrity. Upon light irradiation, the hydrogel's local conductivity can change an unprecedented 10-fold. We also demonstrated soft optoionic devices that are capable of logic processing and photo imaging.

BI-RRT*: An improved path planning algorithm for secure and trustworthy mobile robots systems.

The optimal RRT in elliptic space sampling (Informed-RRT*) is an extension of RRT that provides asymptotic optimality, however, it experiences gradual progress and close to obstacles. In the paper, we propose a novel path planning algorithm guided bidirectional Informed-RRT* (BI-RRT*), that introduces extension range, dual-direction exploration, and refinement in trajectory design. The growth range refers to maintaining an additional area from the obstacle to enhance the dependability of the path through preventing impacts. Bidirectional search is a search strategy using both start and target points for a initial solution. Smoothing improves path robustness by using cubic spline. Furthermore, simulation tests for the BI-RRT* algorithm are executed, and the efficacy of the suggested algorithm is confirmed through its application in a robot operating system (ROS). Simulations and experimental tests verify that the proposed algorithm improves the path planning capability. We emphasize the importance of safety, privacy, and reliability in the deployment of AI systems. Our algorithm ensures that the planned paths maintain a safe distance from obstacles, reducing the risk of collisions. Additionally, we prioritize privacy by adhering to data protection regulations and implementing secure communication protocols within the AI system. Moreover, we have applied rigorous testing and validation processes to enhance the reliability of our algorithm, ensuring consistent and accurate path planning outcomes.

Synthesis of compounds based on the active domain of cabotegravir and their application in inhibiting tumor cells activity.

Structural modification based on existing drugs, which ensures the safety of marketed drugs, is an essential approach in developing new drugs. In this study, we modified the structure of cabotegravir by introducing the front alkyne on the core structure through chemical reaction, resulting in the synthesis of 9 compounds resembling 1,2,3-triazoles. The potential of these new cabotegravir derivatives as tumor suppressors in gastrointestinal tumors was investigated. Based on the MTT experiment, most compounds showed a reduction in the viability of KYSE30 and HCT116 cells. Notably, derivatives 5b and 5h exhibited the most significant inhibitory effects. To further explore the effects of derivatives 5b and 5h on gastrointestinal tumors, KYSE30 cells were chosen as a representative cell line. Both derivatives can effectively curtail the migration and invasion capabilities of KYSE30 cells and induce apoptosis in a dose-dependent manner. We further demonstrated these derivatives induce cell apoptosis in KYSE30 cells by inhibiting the expression of Stat3 protein and Smad2/3 protein. Based on the above results, we suggest they show promise in developing drugs for esophageal squamous cell carcinoma.

Positive Synergy between the Helical Poly(phenylacetylene) Backbones and the Helical L-Proline Oligopeptide Pendants for Enhanced Enantioseparation Properties.

A series of optically active helical poly(phenylacetylene)s (PPA-Pro1, PPA-Pro3, PPA-Pro6, PPA-Pro9, and PPA-Pro12) bearing different chain lengths of L-proline oligopeptide in the side chains were obtained by polymerizing the corresponding novel phenylacetylene monomers. The monomer adopted a trans-rich helix structure when the L-proline oligopeptide chain length was longer, according to the optical activities and 2D-NMR analysis. The helical structure could be maintained and significantly influenced the polymers' helical conformation by introducing the L-proline oligopeptide to the pendants. By the way, the morphology of PPA-Pro3 was observed by atomic force microscope (AFM) on highly oriented pyrolytic graphite (HOPG), and the information on the helix direction, pitch, and chain arrangement was obtained. Also, the chiral separation properties of these polymer-based chiral stationary phases (CSPs) were investigated using high-performance liquid chromatography (HPLC). The poly(phenylacetylene)s showed enhanced enantioseparation properties toward various racemates depending on the longer chain length of the L-proline oligopeptide in the pendants and the positive synergy between the helical backbone and helical side chains. Particularly, PPA-Pro9 showed comparable or even superior enantioseparation properties for racemates 2 and 9 to four commercial columns (Daicel Chiralpak or Chiralcel AD, AS, OD, and OT), indicating that these poly(phenylacetylene)-based CSPs have potential practical values. This work presented here provides inspiration for the further development of CSPs based on a new paradigm.

Hybridization of helical poly(phenylacetylene)s bearing L-proline tripeptide pendants into porous silica microspheres as a solvent-tolerable chiral stationary phase for liquid chromatography.

A novel one-handed helical copoly(phenylacetylene) (CPA) bearing L-proline tripeptide pendants and a few triethoxysilyl residues was synthesized and hybridized into SiO2 porous microspheres (PMSs) during microsphere growth through the hydrolytic polycondensation of ethoxysilyl groups. Nuclear magnetic resonance and Fourier transform infrared spectroscopy results verified the successful preparation of CPA and its hybrid product using SiO2 PMSs. The chiral recognition ability of the resulting CPA with a hybridized-type chiral stationary phase (HCSP) for high-performance liquid chromatography (HPLC) was investigated, revealing its high recognition ability for selected racemates. Moreover, the HCSP showed good solvent tolerability, thus broadening the selection of suitable eluents. The separation effect of the HCSP for the racemate N,N-diphenylcyclohexane-1,2-dicarboxamide (7) improved significantly after introducing CHCl3 in the eluent, resulting in separation factors equivalent or superior to common commercially available polysaccharide-based chiral stationary phases. The proposed preparation strategy provides a new and valuable method for obtaining poly(phenylacetylene)-based HCSPs suitable for a wide range of applications and eluent conditions.

Relationship between vaginal microecology and human papillomavirus infection as well as cervical intraepithelial neoplasia in 2,147 women from Wenzhou, the southeast of China.

Objective: The female reproductive tract is a significant microecological region, and its micro-environment can directly affect women's cervical health. This research aimed to investigate the effect of vaginal microecology on human papillomavirus (HPV) infection and cervical intraepithelial neoplasia(CIN). Methods: A retrospective cohort study enrolling 2,147 women who underwent a colposcopic examination between August 2021 and August 2022 was conducted. The relationship between vaginal microecology and HPV infection as well as cervical lesions were assessed using the chi-square test, univariate and multivariate logistic regression analyses, and Cochran-Armitage trend test. Results: HPV infection was linked to the imbalance of vaginal microecology [odds ratio (OR)=3.00, 95% confidence interval (CI)=1.66-5.43; P<0.001]. Clue cell (OR=1.59, 95% CI=0.99-2.54; P=0.054) and sialidase (OR=1.54, 95% CI=1.01-2.35; P<0.046) were considered as significant risk factors for HPV infection. Further analysis showed that vaginal microecological disorder was more likely to be detected in patients infected with HPV 16/18 subtypes (OR=9.86, 95% CI=2.37-41.80; P=0.002). Although there was no significant correlation between the incidence of vaginal microecological disorder and the severity of cervical lesions (P > 0.05), the proportions of abnormal PH value (OR=2.6, 95% CI=1.63-10.42; P=0.001) and abnormal vaginal cleanliness (OR=2.6, 95% CI=1.36-4.0; P= 0.004) increased as the histological stage progressed. Conclusion: Vaginal microecology associates with HPV infection and the progression of cervical lesions. Detection of vaginal secretion may contribute to the development of targets for micro-environmental modulation with probiotics and the reduction of the incidence of cervical cancer.

Cordyceps militaris Modulates Intestinal Barrier Function and Gut Microbiota in a Pig Model.

This study investigated the effects of Cordyceps militaris (CM) on intestinal barrier function and gut microbiota in a pig model. A total of 160 pigs were randomly allocated to either a control group (fed the basal diet) or a CM group (fed the basal diet supplemented with 300 mg/kg CM). CM improved intestinal morphology and increased the numbers of goblet cells and intraepithelial lymphocytes. CM also elevated the expression of zona occluden-1, claudin-1, mucin-2 and secretory immunoglobulin A. Furthermore, the mucosal levels of pro-inflammatory cytokines were downregulated while the levels of anti-inflammatory cytokines were upregulated in the CM group. Mechanistically, CM downregulated the expression of key proteins of the TLR4/MyD88/NF-κB signaling pathway. Moreover, CM altered the colonic microbial composition and increased the concentrations of acetate and butyrate. In conclusion, CM can modulate the intestinal barrier function and gut microbiota, which may provide a new strategy for improving intestinal health.

A Generalized Iterative Map for Analysis of Protein Sequences.

AIM AND OBJECTIVE: The similarities comparison of biological sequences is an important task in bioinformatics. The methods of the similarities comparison for biological sequences are divided into two classes: sequence alignment method and alignment-free method. The graphical representation of biological sequences is a kind of alignment-free method, which constitutes a tool for analyzing and visualizing the biological sequences. In this article, a generalized iterative map of protein sequences was suggested to analyze the similarities of biological sequences. MATERIALS AND METHODS: Based on the normalized physicochemical indexes of 20 amino acids, each amino acid can be mapped into a point in 5D space. A generalized iterative function system was introduced to outline a generalized iterative map of protein sequences, which can not only reflect various physicochemical properties of amino acids but also incorporate with different compression ratios of the component of a generalized iterative map. Several properties were proved to illustrate the advantage of the generalized iterative map. The mathematical description of the generalized iterative map was suggested to compare the similarities and dissimilarities of protein sequences. Based on this method, similarities/dissimilarities were compared among ND5 protein sequences, as well as ND6 protein sequences of ten different species. RESULTS: By correlation analysis, the ClustalW results were compared with our similarity/dissimilarity results and other graphical representation results to show the utility of our approach. The comparison results show that our approach has better correlations with ClustalW for all species than other approaches and illustrate the effectiveness of our approach. CONCLUSION: Two examples show that our method not only has good performances and effects in the similarity/dissimilarity analysis of protein sequences but also does not require complex computation.

Preparation and Characterization of the Functional Properties of Synthetic Aggregates from Silico-Manganese Slag.

A large number of natural aggregates are used in the field of construction materials, resulting in the exhaustion of natural aggregates. Therefore, looking for an alternative will slow down the consumption of natural aggregates. The sintering method not only consumes a lot of energy to prepare aggregates but also produces a lot of pollutants. In this study, silico-manganese (SM) slag was dried, ground into powder, and used as raw material. Solid and liquid alkaline activator methods were used to prepare SM slag non-burning aggregate (SMNA) by the cold bonding method. The effects of grinding time, amounts of solid and liquid alkaline activators, curing temperature, and the amount of added fly ash on aggregate properties were investigated. The aggregate microstructure was characterized by XRD, SEM, and FTIR methods, and the toxic leaching analysis of aggregate was performed. The results showed that with a fixed amount of liquid activator (16.2% wt.) and solid activator (15% wt.) and fly ash (20% wt.), respectively, and curing was performed at room temperature, the aggregate properties were optimal: the bulk density of 1236.6-1476.9 kg/m3 and the water absorption lower than 4.9-5.5%. The apparent density was 1973.1-2281.6 kg/m3, and the bulk crushing strength was 24.7-27.9 MPa. The XRD, SEM, and FTIR results indicated that amorphous gel could be formed from SM under an alkaline activator, improving the aggregate strength. The results of toxic leaching showed that the aggregate prepared from SM exhibited environmentally friendly characteristics. The SMNA was obtained via the simple and low-energy consumption production process, paving the new way toward large-scale utilization of SM.

Risk factors associated with the persistence of human papillomavirus after cervical excision in patients with high-grade squamous intra-epithelial neoplasia.

OBJECTIVE: To evaluate risk factors associated with the persistence of human papillomavirus (HPV) after cervical excision in patients with high-grade squamous intra-epithelial neoplasia (HSIL). METHODS: A retrospective cohort study enrolled 550 patients who underwent cervical excision for HSIL between January 2015 and January 2018. The effects of various factors were assessed using univariate and multi-variate analyses. RESULTS: The mean age of patients was 42.6 [standard deviation (SD) 8.7, range 22-64] years, and the mean duration of follow-up was 29.0 (SD 4.8, range 24-36) months. Persistent HPV infection after cone excision was detected in 78 (14.2%) patients. Univariate logistic regression analysis revealed that advanced age (>35 years), menopausal status, HPV type (HPV16/18), abnormal vaginal micro-ecological morphology, type of excision (loop electrosurgical excision procedure) and positive margin were closely associated with the persistence of HPV. Multi-variate analysis indicated that menopausal status [odds ratio (OR) 4.708, 95% confidence interval (CI) 2.770-8.001; p < 0.001], abnormal vaginal micro-ecological morphology (OR 2.320, 95% CI 1.372-3.922; p = 0.002) and positive margin (OR 3.346, 95% CI 1.261-8.876; p = 0.015) were significant risk factors for the persistence of HPV after treatment. Furthermore, infection with HPV16/18 increased the risk of persistent infection, and a higher rate of HPV persistence was found in patients who were infected with HPV18 (OR 1.020, 95% CI 0.415-2.505) or co-infected with HPV16/18 (OR 2.064, 95% CI 0.272-2.041) compared with HPV16. CONCLUSION: Persistent HPV infection after surgical treatment for HSIL is considered to be strictly related to the recurrence and progression of disease. Patients who are at increased risk of HPV persistence should receive intensive follow-up after surgery, especially in the first year.

3D Printing of Biocompatible Shape-Memory Double Network Hydrogels.

Shape-memory hydrogels can be fixed to an arbitrary temporary shape and recover their permanent shape under appropriate stimulus conditions. Their shape-memory behavior and biocompatible mechanical and chemical properties impart them with many biomedical applications. However, like most hydrogels, traditional shape-memory hydrogels suffer from intrinsic brittleness due to the network inhomogeneity and high water content. In the past, the double network (DN) scheme has been proved a robust method to improve the mechanical performance of hydrogels. Although 3D printing of DN hydrogels has been realized before, 3D printable shape-memory DN hydrogels have not been achieved so far. In this work, we propose a one-pot method for printing a biocompatible shape-memory DN hydrogel via fused deposition method. The two networks incorporated to the hydrogel ink are polyacrylamide (PAAm) and gelatin. The PAAm network is covalently cross-linked and responsible for the permanent shape, while the gelatin network has thermoreversible cross-links and responsible for fixing the temporary shape. The DN hydrogel shows 3 to 7 times higher fracture toughness than a single network gelatin or PAAm hydrogel and can be fixed to 300% of its original length under tension and 10% of its original thickness under compression. The ink compositions are tuned for optimal printing quality and shape-memory performance. The robust mechanical integrity and dramatic shape transformation capability of the 3D-printed shape-memory DN hydrogel will open-up new potential applications in transformative medical robots and self-deployable devices.

A Photoresponsive Hydrogel with Enhanced Photoefficiency and the Decoupled Process of Light Activation and Shape Changing for Precise Geometric Control.

Traditional shape-morphing hydrogels rely on structural implementation of inhomogeneity inside the material during fabrication to realize predetermined complex shape change upon activation. In recent years, several systems with reprogrammable shape-morphing capabilities have been developed. Among those, the photoresponsive hydrogels offer the best spatial and temporal control. However, for most photoresponsive hydrogels, upon light irradiation, they simultaneously deform, which requires the projection of the light pattern to be continuously adaptive to the deforming gel. It is impractical for complex 3D morphing. In this paper, by incorporating two photodissociable molecules that can form a reactive ion couple upon light activation into one hydrogel, the light irradiation process is decoupled with the morphing process, and the consumption of the reactive ion couple drives the reversible photochemical reaction forward. Consequently, the photochemical reaction efficiency is improved, and the photoresponsive molecules are locked in the activated state until a recovery stimulus is applied. Based on the proposed general scheme, a specific example is given by incorporating the triphenylmethane leucohydroxide and 2-nitrobenzaldehyde molecules into a polyacrylamide hydrogel. The swelling behavior is characterized, and the reprogrammable morphing with precisely controlled geometry is demonstrated.

Design and flight results of the VHF/UHF communication system of Longjiang lunar microsatellites.

As a part of China's Chang'e-4 lunar far side mission, two lunar microsatellites for low frequency radio astronomy, amateur radio and education, Longjiang-1 and Longjiang-2, were launched as secondary payloads on 20 May 2018 together with the Queqiao L2 relay satellite. On 25 May 2018, Longjiang-2 successfully inserted itself into a lunar elliptical orbit of 357 km × 13,704 km, and became the smallest spacecraft which entered lunar orbit with its own propulsion system. The satellite carried the first amateur radio communication system operating in lunar orbit, which is a VHF/UHF software defined radio (SDR) designed for operation with small ground stations. This article describes and evaluates the design of the VHF/UHF radio and the waveforms used. Flight results of the VHF/UHF radio are also presented, including operation of the radio, performance analysis of downlink signals and the first lunar orbit UHF very-long-baseline interferometry (VLBI) experiment.

Impaired Mitochondrial Function Results from Oxidative Stress in the Full-Term Placenta of Sows with Excessive Back-Fat.

The aim of this study was to determine the effect of excessive back-fat (BF) of sows on placental oxidative stress, ATP generation, mitochondrial alterations in content and structure, and mitochondrial function in isolated trophoblasts. Placental tissue was collected by vaginal delivery from BFI (15-20 mm, n = 10) and BFII (21-27 mm, n = 10) sows formed according to BF at mating. Our results demonstrated that excessive back-fat contributed to augmented oxidative stress in term placenta, as evidenced by excessive production of ROS, elevated protein carbonylation, and reduced SOD, GSH-PX, and CAT activities (p < 0.05). Indicative of mitochondrial dysfunction, reduced mitochondrial respiration in cultured trophoblasts was linked to decreased ATP generation, lower mitochondrial Complex I activity and reduced expression of electron transport chain subunits in placenta of BFII sows (p < 0.05). Meanwhile, we observed negative alterations in mitochondrial biogenesis and structure in the placenta from BFII group (p < 0.05). Finally, our in vitro studies showed lipid-induced ROS production resulted in mitochondrial alterations in trophoblasts, and these effects were blocked by antioxidant treatment. Together, these data reveal that excessive back-fat aggravates mitochondrial injury induced by increased oxidative stress in pig term placenta, which may have detrimental consequences on placental function and therefore impaired fetal growth and development.

Bistable non-volatile resistive memory devices based on ZnO nanoparticles embedded in polyvinylpyrrolidone.

The resistive random access memory (RRAM) devices based on polyvinylpyrrolidone (PVP) and PVP:PVP:zinc oxide nanoparticle (ZnO NP) active layers have bistable electrical switching behavior. Herein, via a series of storage performance tests, it was proved that the ITO/PVP:ZnO/Al device has a higher ON/OFF current ratio and better memory performance than the ITO/PVP/Al device. Moreover, at 13 wt% concentration of ZnO NPs, optimal storage performance was obtained, the switch state current ratio significantly increased, and the threshold voltage obviously decreased. The conduction mechanism of the devices was further discussed. The device having inorganic nanoparticles embedded in the polymer has excellent storage performance, which has potential application value in data storage.

Flash memory devices and bistable nonvolatile resistance switching properties based on PFO doping with ZnO.

In this study, poly(9,9-dioctylfluorene-2,7-diyl) (PFO) was synthesized through the Suzuki reaction, and it was characterized. A sandwich type memory device based on PFO and PFO:ZnO, was fabricated using rotary-coating technology. I-V characteristics of the device were studied, and the effects of ZnO nanoparticle (NP) doping content on the performances of the device were discussed. The best doping content of ZnO NPs was found by processing the experimental results (4.76 wt%). Also, the stability of the device was tested, and it was found that the device remained stable after a long testing period. Furthermore, the switching mechanism of the device was discussed.

Super strong dopamine hydrogels with shape memory and bioinspired actuating behaviours modulated by solvent exchange.

Dopamine-containing hydrogels were synthesized by copolymerization of dopamine methacrylamide (DMA), N,N-dimethylacrylamide (DMAA), and an N,N'-methylenebisacrylamide (BIS) crosslinker in a mixed solvent of water and DMSO. The association of DMA was formed by simply immersing in water to facilely reinforce the hydrogel due to the introduction of the second physical crosslinking. The tensile strength of the hydrogels was increased greatly and regulated in a wide range from 200 kPa to over 2 MPa. The association of DMA was destroyed upon immersing in DMSO. This reversible formation and dissociation of the association structure endowed the hydrogel with shape memory and actuating capabilities. Rapid shape fixing in water and complete shape recovery in DMSO was realized within several minutes. Bioinspired functional soft actuators were designed based on the reversible association and metal ion coordination of DMA, including fast responsive hydrogel tentacles, programable multiple shape change, reversible and versatile painting and writing "hydrogel paper". The facile preparation and strength regulation provide a new way to design novel soft actuators through solvent exchange, and will inspire more complex applications upon combining the association with other properties of mussel inspired dopamine derivatives.

Bistable electrical switching and nonvolatile memory effects by doping different amounts of GO in poly(9,9-dioctylfluorene-2,7-diyl).

Poly(9,9-dioctylfluorene-2,7-diyl) (PFO) was synthesized under a Suzuki coupling reaction, and its structure was proved by Fourier transform infrared (FT-IR) spectroscopy, and hydrogen and carbon nuclear magnetic resonance (1H-NMR and 13C-NMR). A nonvolatile organic memristor, based on active layers of PFO and PFO:GO composite, was prepared by spin-coating and the influence of GO concentration on the electrical characteristics of the memristor was investigated. The results showed that the device had two kinds of conductance behavior: electric bistable nonvolatile flash memory behavior and conductor behavior. With an increase in GO concentration, the device has an increased ON/OFF current ratio, increasing from 2.1 × 101 to 1.9 × 103, a lower threshold voltage (V SET), decreasing from -1.1 V to -0.7 V, and better stability. The current remained stable for 3 hours in both the ON state and OFF state, and the ON and OFF state current of the device did not change substantially after 9000 read cycles.

Multivalent cations-triggered rapid shape memory sodium carboxymethyl cellulose/polyacrylamide hydrogels with tunable mechanical strength.

A novel multivalent cations-triggered shape memory hydrogels were synthesized in a one-pot method, and interpenetrating double network was formed by chemically cross-linked polyacrylamide (PAM) network and physically cross-linked sodium carboxymethyl cellulose network. The temporary shape was fixed by complexation between a native biopolymer, sodium carboxymethyl cellulose (CMC), and transition metal ions, specifically Fe3+, Ag+, Al3+, Cu2+, Ni2+, and Mg2+. In particular, CMC-Fe3+ hydrogel exhibits excellent shape fixity ratio (95%). Therefore, we chose PAM/CMC1.0-Fe3+ hydrogel as the model material and further investigated its shape recovery process. It was found that a wide range of molecules and anions could be applied to break off the temporary cross-links between CMC and Fe3+. The PAM/CMC composite hydrogels also exhibited excellent tunable mechanical properties. The mechanical properties of the composite hydrogel can be adjusted by changing the cross-linking densities. The presented strategy could enrich the construction as well as application of biopolymers based shape memory hydrogels.