Mud Cake Improver Mul-GX with Lubrication and Interface Enhancement Effect and Its Action Mechanism.

In view of the problems in which the solid content of drilling fluid increases in the middle and late stages of horizontal well drilling, the lubricity of mud cakes on the borehole wall decreases, and the friction of pipe string increases due to the gradual thickening of mud cakes, which leads to the sticking and the obvious decrease of cementing strength at the second interface, a mud cake improver Mul-GX with lubrication and interface enhancement effect was studied in this paper. Based on the hydration and filling mechanism, the lubricity of the mud cake was improved, its thickness was reduced, and its strength was improved through synergistic effects of solvated water film lubrication and buffering, hardening and crystallization of gelled substances, and filling and dispersion of elastic particles. The mud cake improver Mul-GX is composed of the metasilicate GX-ZQ, polymer copolymer GX-JB, and polymer GX-TX, and the mass ratio of each component was GX-ZQ: GX-JB: GX-TX = 15:1:0.5. The effect of Mul-GX was evaluated through the performance determination of the mud cake and interface cementing simulation experiments. In addition, the microscopic characterization by SEM and XRD were carried out to analyze the mechanism of Mul-GX. The experimental results showed that when Mul-GX was added to the water-based drilling fluid with the 1.0%-1.5% adding quantity, the mud cake lubricity improved by more than 60%, its thickness reduced by 53.9% on average, and its strength increased by 54.3% on average. At the same adding quantity, the interfacial bonding strength was 4.4 times more than the data before adding Mul-GX. All of the results showed that Mul-GX has obvious mud cake lubrication effect and interface enhancement effect.

Experience of multidisciplinary medical teams on humanistic palliative care in oncology wards: a descriptive qualitative study in Southern China.

OBJECTIVES: This study aimed to explore the experiences of multidisciplinary medical teams in implementing humanistic palliative care within the oncology ward. DESIGN: Purposive and snowball sampling methods were used in this qualitative study, which involved conducting semistructured interviews to gather personal experiences from members of multidisciplinary medical teams providing humanistic palliative care in the oncology ward. SETTING: The research was conducted in the oncology ward of a tertiary hospital located in Foshan, China. PARTICIPANTS: Participants included 4 doctors, 12 nurses and 2 medical social workers who form the multidisciplinary medical team responsible for delivering humanistic palliative care to patients with cancer in oncology wards. RESULTS: Phenomenological qualitative analysis yielded 3 main themes and 9 subthemes. The identified themes were as follows: (1) conceptual change, (2) concrete actions and (3) facilitators and barriers to the implementation of humanistic palliative care. CONCLUSION: The findings suggest a need for strengthening humanistic consciousness among multidisciplinary palliative care teams working in oncology wards, although there has been a gradual improvement in humanistic care behaviours. Furthermore, facilitators and barriers coexist in the implementation of humanistic palliative care. Efforts should be directed towards refining mechanisms that promote humanistic palliative care, fostering the enthusiasm of healthcare professionals, conducting systematic training to enhance their humanistic care abilities and striving for improvements in the quality of medical services for the benefit of both patients and their families.

Visual Detection and Sensing of Mercury Ions and Glutathione Using Fluorescent Copper Nanoclusters.

Visual detection of mercury ions and glutathione is of great significance to public health and environmental issues. Herein, we developed a fluorescent sensor (l-Cys/CuNCs@ESM) based on the eggshell membrane (ESM) and red-emitting copper nanoclusters (CuNCs) by the in situ strategy via l-cysteine (l-Cys) as the reducing and protective agent for mercury ions and glutathione sensing visually. The as-prepared fluorescent product had good stability, portability, large Stokes shift (250 nm), and long fluorescence lifetime (7.3 µs). Notably, the l-Cys/CuNCs@ESM exhibited a specific fluorescence quenching response toward Hg2+. Moreover, the interaction between glutathione (GSH) and Hg2+ could subsequently recover the fluorescence effectively. Inspired by this "on-off-on" switch, the l-Cys/CuNCs@ESM was applied as the dual-sensing system for visual detection of mercury ions and glutathione integrating with the portable smartphone. The limit of detection (LOD) of Hg2+ is 1.1 µM for visualization and 0.52 µM for the fluorescence spectrometer. The corresponding LODs of GSH are 2.8 and 0.59 µM, respectively. This platform presents significant sensitivity, specificity, and stability, offering a promising potential for real-time/on-site sensing.

Overexpression of the maize genes ZmSKL1 and ZmSKL2 positively regulates drought stress tolerance in transgenic Arabidopsis.

KEY MESSAGE: Overexpression in Arabidopsis of the maize shikimate kinase-like genes SKL1 and SKL2 enhances tolerance to drought stress. The shikimate pathway has been reported to play an important role in plant signaling, reproduction, and development. However, its role in abiotic stress has not yet been reported. Here, two shikimate kinase-like genes, SKL1 and SKL2, were cloned from maize and their functions in mediating drought tolerance were investigated. Transcript levels of ZmSKL1 and ZmSKL2 in roots and leaves were strongly induced by drought stress. Both proteins were localized in the chloroplast. Furthermore, compared to the wild-type, transgenic Arabidopsis plants overexpressing ZmSKL1 or ZmSKL2 exhibited improved drought stress tolerance through increases in relative water content and stomatal closure. Additionally, the transgenic lines showed reduced accumulation of reactive oxygen species as a results of increased antioxidant enzyme activity. Interestingly, overexpression of ZmSKL1 or ZmSKL2 also increased sensitivity to exogenous abscisic acid. In addition, the ROS-related and stress-responsive genes were activated in transgenic lines under drought stress. Moreover, ZmSKL1 and ZmSKL2 were found to separately interact with ZmASR3, which is an important regulatory protein in mediating drought tolerance, suggesting that ZmSKL1 and ZmSKL2, together with ZmASR3, are proteins that may confer drought tolerance as candidates in plant genetic breeding manipulations.

Yeast powder derived carbon quantum dots for dopamine detection and living cell imaging.

Dopamine (DA) is an important neurotransmitter in the brain of mammals. There is a critical need for fast and sensitive determination approaches to monitor these potential diseases due to various weaknesses in clinical trials of the existing methods for DA detection. DA can effectively quench the fluorescence of carbon quantum dots (CDs) through the inner filter effect and static quenching. In this work, fluorescent yeast CDs (Y-CDs) were prepared via a simple hydrothermal approach of using yeast powder and regarded as the fluorescent nanoprobe to directly monitor the DA concentration. The as-prepared detection platform exhibited excellent sensitivity and selectivity toward DA with a low detection limit of 30 nM and a wide linear range of 0.05-150 µM. Benefiting from these outstanding features, the developed label-free method has been successfully applied for fast DA detection in human serum samples with satisfactory recoveries. Furthermore, it demonstrated that the Y-CDs were well suitable for live cell imaging and showed low toxicity toward MCF-7 cells. Consequently, this work will facilitate the great potential of the versatile Y-CDs in developing biosensors for clinical diagnosis and other biological applications.