Effect of primary tumor volume on survival of concurrent chemoradiotherapy in stage IV non-small cell lung cancer.

OBJECTIVE: To explore the survival effect of thoracic gross tumor volume (GTV) in three-dimensional (3D) radiotherapy for stage IV non-small cell lung cancer (NSCLC). METHODS: The data cases were obtained from a single-center retrospective analysis. From May. From 2008 to August 2018, 377 treatment criteria were enrolled. GTV was defined as the volume of the primary lesion and the hilus as well as the mediastinal metastatic lymph node. Chemotherapy was a platinum-based combined regimen of two drugs. The number of median chemotherapy cycles was 4 (2-6), and the cut-off value of the planning target volume (PTV) dose of the primary tumor was 63 Gy (30-76.5 Gy). The cut-off value of GTV volume was 150 cm3 (5.83-3535.20 cm3). RESULTS: The survival rate of patients with GTV <150 cm3 is better than patients with GTV ≥150 cm3. Multivariate Cox regression analyses suggested that peripheral lung cancer, radiation dose ≥63 Gy, GTV <150 cm3, 4-6 cycles of chemotherapy, and CR + PR are good prognostic factors for patients with stage IV non-small cell lung cancer. The survival rate of patients with GTV <150 cm3 was longer than patients with ≥150 cm3 when they underwent 2 to 3 cycles of chemotherapy concurrent 3D radiotherapy (p < 0.05). When performing 4 to 6 cycles of chemotherapy concurrent 3D radiotherapy, there was no significant difference between <150 cm3 and ≥150 cm3. CONCLUSIONS: The volume of stage IV NSCLC primary tumor can affect the survival of patients. Appropriate treatment methods can be opted by considering the volume of tumors to extend patients' lifetime to the utmost.

Marine thermal fluctuation induced gluconeogenesis by the transcriptional regulation of CgCREBL2 in Pacific oysters.

Marine thermal fluctuation profoundly influences energy metabolism, physiology, and survival of marine life. In the present study, short-term and long-term high-temperature stresses were found to affect gluconeogenesis by inhibiting PEPCK activity in the Pacific oyster (Crassostrea gigas), which is a globally distributed species that encounters significant marine thermal fluctuations in intertidal zones worldwide. CgCREBL2, a key molecule in the regulation of gluconeogenesis, plays a critical role in the transcriptional regulation of PEPCK in gluconeogenesis against high-temperature stress. CgCREBL2 was able to increase the transcription of CgPEPCK by either binding the promoter of CgPEPCK gene or activating CgPGC-1α and CgHNF-4α after short-term (6 h) high-temperature stress, while only by binding CgPEPCK after long-term (60 h) high-temperature stress. These findings will further our understanding of the effect of marine thermal fluctuation on energy metabolism on marine organisms.

Global, regional, and national burden of intracerebral hemorrhage and its attributable risk factors from 1990 to 2021: results from the 2021 Global Burden of Disease Study.

BACKGROUND: Intracerebral hemorrhage (ICH) results from the rupture of blood vessels causing bleeding within the brain and is one of the major causes of death and long-term disability globally, particularly in low- and middle-income countries. Despite having a lower incidence than ischemic stroke, ICH imposes a greater social and economic burden. To our knowledge, since the release of the 2021 Global Burden of Disease (GBD) report, there has been no comprehensive update on the epidemiology and trends of ICH. This study aims to analyze the impact of gender, age, and the Sociodemographic Index (SDI) on the burden of ICH at global, regional, and national levels. METHODS: Data on the incidence, deaths, and disability-adjusted life years (DALYs) of ICH and its related risk factors from 1990 to 2021 were extracted from the GBD 2021 project, encompassing 203 countries and regions. Furthermore, temporal trends of the global intracerebral hemorrhage burden were assessed through Joinpoint analysis. RESULTS: In 2021, there were 3.444 million new cases of ICH worldwide, with an age-standardized prevalence rate of 40.8 per 100,000 people, representing a 31.4% decrease compared to 1990. In 2021, ICH caused 3.308 million deaths, with an age-standardized mortality rate of 39.1 per 100,000 people, a reduction of 36.6% since 1990. Globally, ICH accounted for 79.457 million DALYs, with an age-standardized DALY rate of 92.4 per 100,000 people, representing a 39.1% decrease since 1990. Regionally, Central Asia, Oceania, and Southeast Asia had the highest age-standardized prevalence rates of ICH, whereas Australasia, high-income North America, and Western Europe had the lowest rates. Nationally, the Solomon Islands, Mongolia, and Kiribati had the highest age-standardized prevalence rates, whereas Switzerland, New Zealand, and Australia had the lowest. Hypertension, smoking, and environmental pollution were identified as the primary risk factors for ICH. This study also validated the significant association between SDI and the burden of ICH, with the age-standardized DALY rate of ICH decreasing significantly as SDI increased. CONCLUSION: Despite the decreasing burden of intracerebral hemorrhage, it remains a significant public health issue in countries with a lower SDI. Prevention strategies should prioritize hypertension management, air quality improvement, and smoking control to further mitigate the impact of intracerebral hemorrhage.

Feasibility of the inhibitor development for cancer: A systematic approach for drug design.

The traditional Chinese medicine (TCM) bupleurum-ginger-licorice formula presents significant anti-cancer effects, but its active ingredients and inhibitory mechanism remain unclear. In this work, the core effective ingredient quercetin and its signal transducer and activator of transcription 3 (Stat3) receptor both were identified by network pharmacology. Quercetin is a low-toxicity, non-carcinogenic flavonoid with antioxidant, anti-inflammatory and anticancer activities, which is widely distributed in edible plants. Stat3 can bind to specific DNA response elements and serves as a transcription factor to promote the translation of some invasion/migration-related target genes, considered as a potential anticancer target. Here, molecular docking and molecular dynamics (MD) simulation both were used to explore molecular recognition of quercetin with Stat3. The results show that quercetin impairs DNA transcription efficiency by hindering Stat3 dimerization, partially destroying DNA conformation. Specifically, when the ligand occupies the SH2 cavity of the enzyme, spatial rejection is not conductive to phosphokinase binding. It indirectly prevents the phosphorylation of Y705 and the formation of Stat3 dimer. When the inhibitor binds to the DT1005 position, it obviously shortens the distance between DNA and DBD, enhances their binding capacity, and thereby reduces the degree of freedom required for transcription. This work not only provides the binding modes between Stat3 and quercetin, but also contributes to the optimization and design of such anti-cancer inhibitors.

Appropriate delay of primary tumour radiotherapy may lead to better long-term overall survival for non-small cell lung cancer treated with EGFR-TKIs.

PURPOSE: The most appropriate time of primary tumor radiotherapy in non-small cell lung cancer(NSCLC) with EGFR-TKIs remains unclear. The aim of this study was to investigate the effect of the time factor of primary tumor radiotherapy on long-term overall survival(OS)and provide a theoretical basis for further clinical research. PATIENTS AND METHODS: In total, 238 patients with EGFR-TKIs and OS ≥ 12 months were statistically analysed. Patients were grouped: the D group without primary tumor radiotherapy and the R group with it.The R group were divided into three groups according to the interval between the start of EGFR-TKIs and the start of primary tumor radiotherapy: R0 - 30(<30 days), R30 - PD(≥ 30 days and disease stable), and RPD(radiotherapy after disease progression). The Kaplan-Meier method and log-rank test were used for survival analyses. Exploratory landmark analyses were investigated. RESULTS: The OS rates at 1, 2, 3, 5 years for the R group and D group were 96.8%, 62.9%, 38.3%, 17.1%, and 95.6%, 37.7%, 21.8%, 2.9%, respectively; the corresponding MST was 29 months(95% CI: 24.3-33.7) for the R group and 22 months(95% CI: 20.4-23.6) for the D group (χ2 = 13.480, p<0.001). Multivariate analysis revealed that primary tumor radiotherapy was independent predictors of prolonged OS.Among the four groups, The R30 - PD appeared to have the best OS (D, χ2 = 19.307, p<0.001;R0 - 30, χ2 = 11.687, p = 0.01; RPD, χ2 = 4.086, p = 0.043). Landmark analyses(22 months) showed the R30 - PD group had a significant long-term OS.The incidence of radiation pneumonitis ≥ grade 2 was17.3%(n = 19)and radiation esophagitis ≥ grade 2 was observed in 32 patients(29.1%). CONCLUSIONS: Our results showed that primary tumour radiotherapy may prolong long-term OS with acceptable toxicities. Appropriate delay(R30 - PD)of primary tumour radiotherapy may be the best choice.Premature radiotherapy(R0 - 30) and radiotherapy after disease progression (RPD)may not be reasonable for long-term OS.

Protocatechuic acid enhanced the selective degradation of sulfonamide antibiotics in Fe(III)/peracetic acid process under actually neutral pH conditions.

The practical application of the Fe-catalyzed peracetic acid (PAA) processes is seriously restricted due to the need for narrow pH working range and poor anti-interference capacity. This study demonstrates that protocatechuic acid (PCA), a natural and eco-environmental phenolic acid, significantly enhanced the removal of sulfonamide antibiotics in Fe(III)/PAA process under actually neutral pH conditions (6.0-8.0) by complexing Fe(III). With sulfamethoxazole (SMX) as the model contaminant, the pseudo-first-order rate constant of SMX elimination in PCA/Fe(III)/PAA process was 63.5 times higher than that in Fe(III)/PAA process at pH 7.0, surpassing most of the previously reported strategies-enhanced Fe-catalyzed PAA processes (i.e., picolinic acid and hydroxylamine etc.). Excluding the primary contribution of reactive species commonly found in Fe-catalyzed PAA processes (e.g., •OH, R-O•, Fe(IV)/Fe(V) and 1O2) to SMX removal, the Fe(III)-peroxy complex intermediate (CH3C(O)OO-Fe(III)-PCA) was proposed as the primary reactive species in PCA/Fe(III)/PAA process. DFT theoretical calculations indicate that CH3C(O)OO-Fe(III)-PCA exhibited stronger oxidation potential than CH3C(O)OO-Fe(III), thereby enhancing SMX removal. Four potential removal pathways of SMX were proposed and the toxicity of reaction solution decreased with the removal of SMX. Furthermore, PCA/Fe(III)/PAA process exhibited strong anti-interference capacity to common natural anions (HCO3-, Cl-and NO3-) and humic acid. More importantly, the PCA/Fe(III)/PAA process demonstrated high efficiency for SMX elimination in actual samples, even at a trace Fe(III) dosage (i.e., 5 µM). Overall, this study provided a highly-efficient and eco-environmental strategy to remove sulfonamide antibiotics in Fe(III)/PAA process under actually neutral pH conditions and to strengthen its anti-interference capacity, underscoring its potential application in water treatment.

Alginate-containing 3D-printed hydrogel scaffolds incorporated with strontium promotes vascularization and bone regeneration.

Bone defects persist as a significant challenge in the field of clinical orthopedics. This study focuses on the fabrication and characterization of 3D-printed composite hydrogel scaffolds composed of sodium alginate, gelatin, and α-tricalcium phosphate (α-TCP) with varying ratios of Strontium ions (Sr2+). These scaffolds aim to address the clinical challenges associated with bone defect repair by providing mechanical support and promoting bone formation and vascularization. The degradation, swelling, mechanical properties, and release profiles of Sr2+ from the hydrogel scaffolds were comprehensively characterized. In vitro tests were conducted to assess cell viability and proliferation, as well as osteogenic and angiogenic gene expression, to investigate the osteogenic and pro-angiogenic potential of the composite hydrogel scaffolds. Furthermore, skull defect simulations were performed, and composite scaffolds with varying Sr2+ ratios were implanted to evaluate their effectiveness in bone repair. This research establishes a foundation for advancing bone tissue engineering through composite scaffolds containing biological macromolecules and strontium, with alginate serving as a key element in enhancing performance and expanding clinical applicability.

Impact of ozonation on disinfection byproducts formation from phenylalanine during chlorination.

As a strong oxidizing agent, ozone is used in some water treatment facilities for disinfection, taste and odor control, and removal of organic micropollutants. Phenylalanine (Phe) was used as the target amino acid to comprehensively investigate variability of disinfection byproducts (DBPs) formation during chlorine disinfection and residual chlorine conditions subsequent to ozonation. The results showed that subsequent to ozonation, the typical regulated and unregulated DBPs formation potential (DBPsFP), including trichloromethane (TCM), dichloroacetonitrile (DCAN), chloral hydrate (CH), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), and trichloroacetamide (TCAcAm) increased substantially, by 2.4, 3.3, 5.6, 1.2, 2.5, and 6.0 times, respectively, compared with only chlorination. Ozonation also significantly increased the DBPs yield under a 2 day simulated residual chlorine condition that mimicked the water distribution system. DBPs formations followed pseudo first order kinetics. The formation rates of DBPs in the first 6 hr were higher for TCM (0.214 hr-1), DCAN (0.244 hr-1), CH (0.105 hr-1), TCAcAm (0.234 hr-1), DCAA (0.375 hr-1) and TCAA (0.190 hr-1) than thereafter. The peak DBPsFP of TCM, DCAN, CH, TCAcAm, DCAA, and TCAA were obtained when that ozonation time was set at 5-15 min. Ozonation times > 30 min increased the mineralization of Phe and decreased the formation of DBPs upon chlorination. Increasing bromine ion (Br-) concentration increased production of bromine- DBPs and decreased chlorine-DBPs formation by 59.3%-92.2% . Higher ozone dosages and slight alkaline favored to reduce DBP formation and cytotoxicity. The ozonation conditions should be optimized for all application purposes including DBPs reduction.

Living Synthelectronics: A New Era for Bioelectronics Powered by Synthetic Biology.

Bioelectronics, which converges biology and electronics, has attracted great attention due to their vital applications in human-machine interfaces. While traditional bioelectronic devices utilize nonliving organic and/or inorganic materials to achieve flexibility and stretchability, a biological mismatch is often encountered because human tissues are characterized not only by softness and stretchability but also by biodynamic and adaptive properties. Recently, a notable paradigm shift has emerged in bioelectronics, where living cells, and even viruses, modified via gene editing within synthetic biology, are used as core components in a new hybrid electronics paradigm. These devices are defined as "living synthelectronics," and they offer enhanced potential for interfacing with human tissues at informational and substance exchange levels. In this Perspective, the recent advances in living synthelectronics are summarized. First, opportunities brought to electronics by synthetic biology are briefly introduced. Then, strategic approaches to designing and making electronic devices using living cells/viruses as the building blocks, sensing components, or power sources are reviewed. Finally, the challenges faced by living synthelectronics are raised. It is believed that this paradigm shift will significantly contribute to the real integration of bioelectronics with human tissues.

The expression patterns of exosomal miRNAs in the Pacific oyster after high-temperature stress or Vibrio stimulation.

The exosomal miRNA plays a crucial role in the intercellular communication response to environmental stress and pathogenic stimulation. In the present study, the expression of exosomal miRNAs in the Pacific oyster Crassostrea gigas after high-temperature stress or Vibrio splendidus stimulation was investigated through high-throughput sequencing. The exosomes were identified to be teardrop-like vesicles with the average size of 81.7 nm by transmission electron microscopy. There were 66 known miRNAs and 33 novel miRNAs identified, of which 10 miRNAs were differentially expressed after both high-temperature stress and Vibrio stimulation compared to the control group. A total of 1868 genes were predicted as the putative targets of miRNAs, of which threonine aspartase 1-like was targeted by the highest number of related miRNAs. The robustness and reliability of miRNA expression from the sRNA sequencing data were verified by employing eight miRNAs for qPCR. GO and KEGG clustering analyses revealed that apoptosis was significantly enriched by the target genes of differentially expressed exosomal miRNAs after high-temperature stress, and autophagy and cytokine activity were significantly enriched after Vibrio stimulation. Energy metabolism was found to be significantly shared in the target gene enrichments after both high-temperature stress and Vibrio stimulation. These findings would improve our understanding of the regulatory mechanisms of exosomal miRNAs in C. gigas after high-temperature stress or Vibrio stimulation.

A Continuous Volatility Forecasting Model Based on Neural Differential Equations and Scale-Similarity.

Volatility forecasting is a problem in finance that attracts the attention of both academia and industry. While existing approaches typically utilize a discrete-time latent process that governs the volatility to forecast its future level, volatility is considered to evolve continuously, which makes discrete-time modeling inevitably lose some critical information about the evolution of volatility. In this article, a novel neural-network-based model, Continuous Volatility Forecasting Model, CVFM is proposed to tackle this problem. First, CVFM introduces a continuous-time latent process, whose evolution is modeled with neural differential equations (NDEs), to govern volatility, which effectively captures the continuous evolutionary behavior of volatility in a data-driven way. Second, a scale-similarity-based mechanism is designed to calibrate the evolution equation of the latent process with real-world observations in the absence of high-frequency data. CVFM is tested on six real-world stock index datasets. The main experimental results show that CVFM can significantly outperform existing models in terms of both forecasting accuracy and high-volatility recognition.

Overlooked Role of Coexistent Hydrogen Peroxide in Activated Peracetic Acid by Cu(II) for Enhanced Oxidation of Organic Contaminants.

Cu(II)-catalyzed peracetic acid (PAA) processes have shown significant potential to remove contaminants in water treatment. Nevertheless, the role of coexistent H2O2 in the transformation from Cu(II) to Cu(I) remained contentious. Herein, with the Cu(II)/PAA process as an example, the respective roles of PAA and H2O2 on the Cu(II)/Cu(I) cycling were comprehensively investigated over the pH range of 7.0-10.5. Contrary to previous studies, it was surprisingly found that the coexistent deprotonated H2O2 (HO2-), instead of PAA, was crucial for accelerating the transformation from Cu(II) to Cu(I) (kHO2-/Cu(II) = (0.17-1) × 106 M-1 s-1, kPAA/Cu(II) < 2.33 ± 0.3 M-1 s-1). Subsequently, the formed Cu(I) preferentially reacted with PAA (kPAA/Cu(I) = (5.84 ± 0.17) × 102 M-1 s-1), rather than H2O2 (kH2O2/Cu(I) = (5.00 ± 0.2) × 101 M-1 s-1), generating reactive species to oxidize organic contaminants. With naproxen as the target pollutant, the proposed synergistic role of H2O2 and PAA was found to be highly dependent on the solution pH with weakly alkaline conditions being more conducive to naproxen degradation. Overall, this study systematically investigated the overlooked but crucial role of coexistent H2O2 in the Cu(II)/PAA process, which might provide valuable insights for better understanding the underlying mechanism in Cu-catalyzed PAA processes.

Response mechanism of soil leachate and disinfection by-product formation to extreme precipitation events under continuous drought scenario.

In this study, a rainfall simulation device was employed to investigate the response mechanism of soil leachate and disinfection by-products formation potential (DBPsFP) to extreme precipitation events. The results revealed that the aromaticity of dissolved organic matter (DOM) and the concentration of hydrophobic DOM containing aromatic carbon groups in leachate decreased with rising temperature. The humification degree of DOM decreased at 25 °C (99 mm/h), while the humification degree and protein-like level of DOM increased under high temperatures droughts (45 °C and 65 °C). Higher temperatures resulted in the leach of more microbial-derived humus and low molecular phenolic compounds from soil and broadened the range of molecular weight distribution. Increasing temperature increased DBPsFP and DBPs species and caused the precursors of haloacetic acids (HAAs) in leachate to become more hydrophobic, while the precursors of trihalomethanes (THMs) became more hydrophilic. Most importantly, the increased temperature attenuated the rainfall-mediated dilution of organic pollutant concentration, and temperature has a more significant effect than extreme rainfall in DOM abundance and the formation potential (or species) of DBPs. The results help to better understand the impact of climate change on the physicochemical processes of water quality.

Study on the Performance Mechanism of Polyformaldehyde Glycol Ether Polymer for Crude Oil Recovery Enhancement.

The demand for energy continues to increase as the global economy continues to grow. The role of oilfield chemicals in the process of oil and gas exploration, development, and production is becoming more and more important, and the demand is rising year by year. The support of national policies and the formulation of environmental protection regulations have put forward higher requirements for oilfield chemical products, which has promoted the innovative research and development and market application of oilfield chemicals. Polyformaldehyde glycol ether polymer (PGEP) is simple to synthesize, easily biodegradable, green and environmentally friendly, and in line with the development trend of chemicals used in oil and gas development. The interfacial tension performance of PGEP after compounding with different surfactants can reach as low as 0.00034 mN/m, which meets the requirements of the oilfield (interfacial tension ≤ 5 × 10-3 mN/m). The best oil washing efficiency performance of PGEP compounded with different surfactants reached 78.2%, which meets the requirements of the oilfield (oil washing efficiency ≥ 40%). The fracturing fluid drainage efficiency of PGEP after compounding with different surfactants reaches 22%, which meets the requirements of the oilfield (drainage efficiency ≥ 15%). The surface interfacial tension of the system remains constant after the concentration exceeds 0.2% and decreases with lower concentrations. The drainage efficiency increases with increasing concentrations in the range below 0.6%. It was determined that PGEP can be used as a surfactant instead of fatty-alcohol ethoxylates (FAE) in oilfield development.

Feasibility of NDEA formation control from DEDTC in chlorination/chloramination by pre-ozonation: Mechanisms and influencing factors.

N-nitrosodiethylamine (NDEA), which is the most toxic nitrosamine among the 9 detected species, has been widely detected in drinking water. Amines containing diethylamine (DEA) groups in the structure would generate NDEA during the disinfection processes. The aim of this study was to evaluate the feasibility of reducing NDEA formation from a commonly used dithiocarbamate pesticide sodium diethyldithiocarbamate (DEDTC) in subsequent chlorination and chloramination by pre-ozonation. The results demonstrated that NDEA could be generated directly during ozonation, its amounts increased from 0 to 14.34 µg/L with increasing ozone dosages (0-4 mg/L), which was higher than that chlorination (2.68 µg/L) and chloramination (4.91 µg/L) when the initial concentration of DEDTC was 20 µM. Pre-ozonation significantly raised NDEA formation from 2.68 to15.32 µg/L in subsequent chlorination; and that from 4.91 to 9.54 µg/L during subsequent chloramination processes. The addition of •OH scavenger tert-butanol (tBA) increased the production of NDEA from 8.14 to 20.80 µg/L during ozonation, and that from 6.76 to17.98 µg/L in O3/HClO process, 8.74 to 17.33 µg/L in O3/NH2Cl process. Except for NO3- and CO32-, most of the co-existing substances promoted NDEA generation from DEDTC under disinfection conditions. Based on the results of Gaussian theory calculations, GC/MS and UPLC-Q-TOFMS analysis, the influencing mechanisms of pre-ozonation on NDEA generation in the subsequent disinfection process were proposed. In addition, not only acute/chronic toxicity calculation but also luminescent bacteria test was performed to assess the possibility of pre-ozonation on the risk control of DEDTC. The research results fill a gap in the control of NDEA pollution and help to develop a safer ozone oxidation technology.

Cellular and molecular mechanisms of fibrosis and resolution in bleomycin-induced pulmonary fibrosis mouse model revealed by spatial transcriptome analysis.

The bleomycin-induced pulmonary fibrosis mouse model is commonly used in idiopathic pulmonary fibrosis research, but its cellular and molecular changes and efficiency as a model at the molecular level are not fully understood. In this study, we used spatial transcriptome technology to investigate the cellular and molecular changes in the lungs of bleomycin-induced pulmonary fibrosis mouse models. Our analyses revealed cell dynamics during fibrosis in epithelial cells, mesenchymal cells, immunocytes, and erythrocytes with their spatial distribution available. We confirmed the differentiation of the alveolar type II (AT2) cell type expressing Krt8, and we inferred their trajectories from both the AT2 cells and club cells. In addition to the fibrosis process, we also noticed evidence of self-resolving, especially to identify possible self-resolving related genes, including Prkca. Our findings provide insights into the cellular and molecular mechanisms underlying fibrosis resolution and represent the first spatiotemporal transcriptome dataset of the bleomycin-induced fibrosis mouse model.

Novel Environmentally Responsive Polyvinyl Polyamine Hydrogels Capable of Phase Transformation with Temperature for Applications in Reservoir Profile Control.

Hydrogel has been widely used in reservoir regulation for enhancing oil recovery, however, this process can experience negative influences on the properties and effects of the hydrogels. Therefore, developing novel hydrogels with excellent environmental responsiveness would improve the formation adaptability of hydrogels. In this study, novel polyvinyl polyamine hydrogels were synthesized by a ring-opening addition reaction between polyvinyl polyamines and polyethylene glycol glycidyl ether. The results of atomic force microscopy and transmission electron microscopy showed that the polyvinyl polyamine gel had a porous and irregular bulk structure and was endowed with water storage. With the temperature rising from 30 °C to 60 °C, the transmittance of diethylenetriamine hydrogel decreased from 84.3% to 18.8%, indicating that a phase transition had occurred. After the polyvinyl polyamine hydrogel with low initial viscosity was injected into the formation in the liquid phase, the increase of the reservoir temperature caused it to turn into an elastomer, thereby migrating to the depth of the reservoir and achieving effective plugging. Polyvinyl polyamine hydrogel could improve the profile of heterogeneous layers significantly by forcing subsequent fluids into the low permeability zone in the form of elastomers in the medium temperature reservoirs of 40-60 °C. The novel environmentally responsive polyvinyl polyamine hydrogels, capable of phase transformation with temperature, exhibited superior performance in recovering residual oil, which was beneficial for applications in reservoir profile control and oilfield development.

Synthesis and Application of a Novel Multi-Branched Block Polyether Low-Temperature Demulsifier.

In this paper, a low-temperature thick oil demulsifier with high polarity was prepared by introducing ethylene oxide, propylene oxide block, and butylene oxide using m-diphenol as a starting agent. The main reasons for the difficulty involved in the low-temperature emulsification of extractive fluids were explained by analyzing the synthetic influencing factors and infrared spectra of the star comb polymer (PR-D2) and by analyzing the four fractions, interfacial energies, and zeta potentials of crude oils from the Chun and Gao fields. The effects of PR-D2 surfactant on the emulsification performance of crude oil recovery fluids were investigated via indoor and field experiments. The experimental results indicate that the optimal synthesis conditions for this emulsion breaker are as follows: a quality ratio of ionic reaction intermediates and meso-diphenol of R = 10:1; 1 g of the initiator; a polymerization temperature of 80 °C; and a reaction time of 8 h. Colloidal asphaltenes in the crude oil were the main factor hindering the low-temperature demulsification of the Gao oilfield's extractive fluids, and the reason for the demulsification difficulty of the extractive fluids in the Chun oilfield is that the temperature of demulsification is lower than the wax precipitation point. The demulsification rate of the Chun oilfield's extractive fluids reached more than 98% when the PR-D2 concentration reached 150 mg/L at 43 °C. The demulsification rate of the Gao oilfield's extractive fluids reached more than 98% at a PR-D2 concentration of 150 mg/L at 65 °C. The field experiments show that the Chun oilfield's extractive fluids can still demulsify after the temperature is reduced to 43 °C in winter. The emulsification temperature of the Gao oilfield's extractive fluids was reduced from 73 °C to 68 °C, with an excellent demulsification effect.

Efficient Demulsification Performance of Emulsified Condensate Oil by Hyperbranched Low-Temperature Demulsifiers.

Focusing on the problem of poor demulsification performance of light crude oil emulsions in low-permeability oilfields at low temperatures, the composition of the emulsion samples, clay particle size distribution, and the viscosity-temperature relationship curve of samples were analyzed. Based on the results of emulsion composition analysis and characteristics, the bottle test method was used to analyze the demulsifying effect of different commercial types of demulsifiers, revealing the demulsification mechanism. The field tests confirm the demulsification capabilities of Polyoxyethylene polyoxypropylene quaternized polyoxyolefins surfactants (PR demulsifiers). The results reveal that PR demulsifiers combine the features of decreasing the interfacial tension between oil and water and adsorbing SiO2, allowing for quick demulsification and flocculation at low temperatures. This research serves as a theoretical and practical foundation for the study and advancement of low-temperature demulsification technology in oilfields.

Removal of the rate table: MEMS gyrocompass with virtual maytagging.

High-performance micro-electro-mechanical system (MEMS) gyrocompasses for north-finding systems have been very popular for decades. In this paper, a MEMS north-finding system (NFS) based on virtual maytagging (VM) is presented for the first time. In stark contrast to previous schemes of MEMS-based NFSs (e.g., carouseling, maytagging) and the abandoning rate table, we developed a honeycomb disk resonator gyroscope (HDRG) and two commercial accelerometers for azimuth detection. Instead of the physical rotation of the integrated turntable in traditional NFSs, the vibratory working modes of the HDRG are rotated periodically with electronic control to reduce the uncertainty in the azimuth. After systematically analyzing the principle of NFSs with VM, we designed tests to verify the practicability at the sensor level. A bias instability of 0.0078°/h can be obtained during one day with VM in an HDRG. We also implemented comparative north-finding experiments to further check our strategy at the system level. The accuracy in the azimuth can reach 0.204° for 5 min at 28.2° latitude with VM and 0.172° with maytagging. The results show that without any mechanical turning parts, VM technology makes it possible to develop high-precision handheld MEMS NFSs.