Subsequent Decrease Research Articles

Changes in positive and negative affect in psychotherapy for depression and anxiety.

Positive and negative affect play critical roles in depression and anxiety treatment, but the dynamic processes of how affect changes over treatment in relation to changes in symptoms is unclear. The study goal was to examine relationships among changes in positive and negative affect with changes in depression and anxiety symptoms. This secondary analysis used a combined sample (N = 196) of two trials (Craske et al., 2019, 2023) comparing positive affect treatment (PAT) to negative affect treatment. Longitudinal cross-lag panel models explored whether changes in positive and negative affect (Positive and Negative Affect Schedule; Watson et al., 1988) predicted subsequent changes in depression and anxiety symptoms (Depression Anxiety Stress Scales; Lovibond & Lovibond, 1995), whether symptoms predicted subsequent changes in affect, and whether treatment condition moderated these relationships. Increases in positive affect predicted subsequent decreases in depression and anxiety symptoms, regardless of treatment condition. Symptoms did not reciprocally predict changes in positive affect. For individuals in PAT, decreases in negative affect predicted subsequent decreases in symptoms. Moreover, decreases in symptoms predicted subsequent decreases in negative affect, regardless of treatment condition. Results did not support a reciprocal relationship between positive affect and symptoms of depression and anxiety since positive affect predicted depression and anxiety symptoms but not vice versa. Results supported a reciprocal relationship between negative affect and symptoms of depression and anxiety since negative affect predicted depression and anxiety symptoms in PAT, and depression and anxiety symptoms predicted negative affect in both treatment conditions. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Abstract 1552: Tumorigenesis of basal muscle invasive bladder cancer was mediated by PTEN protein degradation resulting from SNHG1 upregulation

Abstract hosphatase and tensin homolog deleted on chromosome ten (PTEN) serves as a powerful tumor suppressor, and has been found to be downregulated in human bladder cancer (BC) tissues. Despite this observation, the mechanisms contributing to PTEN’s downregulation have remained elusive. In this study, we discovered that mice exposed to N-butyl-N-(4-hydroxybu-tyl)nitrosamine (BBN), a specific bladder chemical carcinogen, exhibited primary basal muscle invasive BC (BMIBC) accompanied by a pronounced reduction in PTEN protein expression in vivo. Utilizing a lncRNA deep sequencing high-throughput platform, along with gain- and loss-of-function analyses, we identified small nucleolar RNA host gene 1 (SNHG1) as a critical lncRNA that might drive the formation of primary BMIBCs in BBN-treated mice. Cell culture results further demonstrated that BBN exposure significantly induced SNHG1 in normal human bladder urothelial cell UROtsa. Notably, the ectopic expression of SNHG1 alone was sufficient to induce malignant transformation in human urothelial cells, while SNHG1 knockdown effectively inhibited anchorage-independent growth of human BMIBCs. Our detailed investigation revealed that SNHG1 overexpression led to PTEN protein degradation through its direct interaction with HUR. This interaction reduced HUR binding to ubiquitin-specific peptidase 8 (USP8) mRNA, causing degradation of USP8 mRNA and a subsequent decrease in USP8 protein expression. The downregulation of USP8, in turn, increased PTEN poly-ubiquitination and degradation, culminating in cell malignant transformation and BMIBC anchorage-independent growth. In vivo studies confirmed the downregulation of PTEN and USP8, as well as their positive correlations in both BBN-treated mouse bladder urothelium and tumor tissues of bladder cancer in nude mice.Our findings, for the first time, demonstrate that overexpressed SNHG1 competes with USP8 for binding to HUR. This competition attenuates USP8 mRNA stability and protein expression, leading to PTEN protein degradation, consequently, this process drives urothelial cell malignant transformation and fosters BMIBC growth and primary BMIBC formation. Citation Format: Chuanshu Huang, Tengda Li, Honglei Jin. Tumorigenesis of basal muscle invasive bladder cancer was mediated by PTEN protein degradation resulting from SNHG1 upregulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1552.

Polymorphic transformations of titanium oxides contribute to economic uranium mineralization in sandstone

Sandstone-hosted uranium (U) deposits provide a significant U resource for nuclear energy worldwide. Driven by redox reactions, tetravalent uranium-bearing minerals are commonly associated with reductants (e.g., pyrite and organic matter). However, numerous observations have revealed that tetravalent uranium-bearing minerals can spatially coexist with chemically stabilized titanium oxides in sandstone-hosted U deposits, requiring a complementary mechanism to interpret these findings. We present a new model based on in situ texture, trace-element content, and titanium isotopic ratio, as well as polymorph type and related transformation for titanium oxides from the Yaojia Formation of the southwestern Songliao Basin in northeast China. Specifically, in our model, abundant nanopores were generated during the spontaneous transformation of anatase to rutile, producing a porous material for hexavalent U adsorption. Facilitated by a U-rich source rock, adsorbed U in porous titanium oxide from the lower Yaojia Formation was up to several thousand parts per million. In order to minimize surface energy, a subsequent decrease in surface area by merging small pores is inevitable. When the evolved surface area was small enough, hexavalent U would be desorbed and subsequently transformed to tetravalent U by local reductants, forming uraninite nanoparticles on the surface of U-rich rutile with relatively large pores. Our newly proposed mechanism not only contributes to a better understanding of economic U mineralization in sandstone, but also suggests that U occurred as uranium oxide instead of brannerite in sandstone-hosted U deposits, providing a nano-mineralogical perspective required for industrial processing.

Cholesterol depletion induces mesenchymal properties in oral squamous cell carcinoma cell line.

Cholesterol in cell membranes is crucial for cell signaling, adhesion, and migration. Membranes feature cholesterol-rich caveolae with caveolin proteins, playing roles in epithelial-mesenchymal transition and cancer progression. Despite elevated cholesterol levels in tumors, its precise function and the effects of its depletion in oral squamous cell carcinoma remain unclear. The aim of this study was to evaluate the influence of cholesterol depletion in oral squamous cell carcinoma cell line and epithelial-mesenchymal transition process. Cholesterol depletion was induced on SCC-9 cells by methyl-β-cyclodextrin and cell viability, proliferation, apoptosis, and colony formation capacities were evaluated. Gene and protein expressions were evaluated by reverse transcription polymerase chain reaction (RT-qPCR) and Western Blot, respectively, and cell sublocalization was assessed by immunofluorescence. Cholesterol depletion resulted in alteration of oral squamous cell carcinoma cell morphology at different concentrations of methyl-β-cyclodextrin, as well as decreased cell proliferation and viability rates. Analysis of CAV1 transcript expression revealed increased gene expression in the treated SCC-9 during the 24 h period, at different concentrations of methyl-β-cyclodextrin: 5 , 7.5, 10, and 15 mM, in relation to parental SCC-9. CAV1 protein expression was increased, with subsequent dose-dependent decrease. A statistically significant difference was observed in samples treated with 5 mM of methyl-β-cyclodextrin (p = 0.02, Kruskal-Wallis test). The immunofluorescence assay showed lower cytoplasmic and membrane labeling intensity in the treated samples for CAV1. These findings indicate the modulation of cholesterol as a possible mechanism underlying the regulation of these molecules and activation of epithelial-mesenchymal transition in oral squamous cell carcinoma.

Gamma radiation effects on high-temperature superconducting ReBCO tape

High-temperature superconducting (HTS) magnets are crucial components in future fusion reactors, subjected to prolonged irradiation and complex mechanical conditions. While the irradiation sensitivity of HTS materials has been extensively studied, limited research has explored the effects of force conditions during irradiation. This study investigated the influence of irradiation on ReBCO tapes. An irradiation experiment was conducted utilizing a Co60 source irradiation device. Superconductor properties were evaluated through the induction method, while microstructure analysis was performed using x-ray diffraction measurements. The results indicate that the critical current initially increases and subsequently decreases, while the critical temperature remains relatively stable. Furthermore, the bending degree during irradiation affects the critical current density, with a decrease in radius corresponding to a first increase and then subsequent decrease in critical current density. The force applied during irradiation exhibits a impact on the superconducting properties, underscoring the importance of considering force conditions in future investigations.

Spatio-temporal Analysis of Land Surface Temperature in West Tripura District, India

Land surface temperature is a crucial factor that affects many ecological and environmental processes, such as the urban heat island effect, the health of the plants, and the effects of climate change. An increase in global temperature and erratic rainfall has been observed as a result of the weather's change during the recent past. Understanding the Spatio-temporal change of the land surface temperature can provide us with insights for sustainable land use management, urban planning, and also aid in planning and formulating plans to combat climate change. The present study area is the most populated district in Tripura and has experienced some of the fastest transformation in urban infrastructure. This study's objective was to investigate at how the land surface temperature (LST) varies across space and time in the West Tripura District. Landsat- 8 OLI and Landsat-5 ETM was the source of data to investigate the purpose of the study. The LST data was derived from thermal bands of the satellite imagery using remote sensing algorithm in ArcGIS and NDVI was computed using NIR and RED bands. Upto the year 2020, steady rise in built up areas was observed with a decline in land cover until 2010. However, the year 2020 witnessed an increase in vegetation cover. Similarly, the land surface temperature revealed higher values till 2010 may be attributed to loss of vegetation cover and subsequent decrease in values of land surface temperature after 2010 may be attributed to afforestation and growing popularity of plantation schemes.

Quality change in Bombay duck (Harpadon nehereus) surimi during frozen storage using different freezing methods.

To inhibit the quality deterioration caused by the frozen storage of surimi products, this work investigated the effect of freezing methods, including raw-freezing-setting-heating, raw-setting-freezing-heating, and raw-setting-heating-freezing, on quality changes in surimi gel. The moisture loss, physical-chemical properties, and protein structure conformation of surimi gel derived from Bombay duck (BD) were assessed following frozen storage periods of 20, 40, and 60 days. The findings suggest that the raw-setting-heating-freezing method yielded optimal surimi gel properties with extended frozen storage time. Employing this approach led to a reduction in thawing loss, while cooking loss remained constant. After 60 days of frozen storage, the hardness exhibited an initial increase followed by a subsequent decrease, and water-holding capacity increased to 68.2%. Notably, the impact on surimi gel during the late stage of frozen storage was more pronounced throughout the formation of ice crystals, resulting in decreased disulfide bond content. Scanning hematoxylin-eosin (HE) staining slices of samples following thawing and heating demonstrated that the raw-setting-heating-freezing method could better resist the effect of ice crystals in frozen storage period on surimi tissue, while the gel on setting process could delay the erosion imposed on by ice crystals during frozen storage. This study provides a scientific foundation for the industrialization on frozen BD surimi products.

Group member attachment style interacts with actor and partner helping alliance to predict decreasing binge eating episodes

Objective An individual’s attachment style may impact how they interact with their therapy group. This study examined the moderating role of a group member’s attachment on the dynamic relationships between that group member’s (actor) and other group members’ (partner) therapeutic alliances and symptom outcomes. Method: This is a secondary analysis of data from a trial testing the outcome of emotionally-focused group therapy for binge-eating disorder. The sample consisted of 2,360 sessions nested within 118 group members who attended a 20-session treatment. Patients recorded binge eating episodes (BEE), their body weight and an alliance measure session-by-session. Results Dynamic structural equation modelling showed decreases in BEE and weight over the therapy. When attachment style was not included in the model, higher-than-average partner’s alliance scores in the previous session were related to decreases in BEE in the current session. Attachment style moderated these actor and partner effects. For patients with preoccupied attachments, higher-than-average actor alliance in the previous session was related to subsequent decreases in BEE. For patients with dismissing or disorganized attachments, higher partner alliance in the previous session was related to subsequent decreases in BEE. Conclusion Group members’ attachment characteristics can play a role in the development of alliance-outcome patterns in group therapy.

A chemical kinetics theory for interpreting the non-monotonic temperature dependence of enzymatic reactions

Abstract. One notable observation of enzymatic chemical reactions is that, for a given abundance of enzymes and substrates, temperature increases cause reaction rates to first increase consistent with the Arrhenius relationship, then plateau, and finally fall off quickly to zero at high temperatures. While many mathematical functions have been used to describe this pattern, we here propose a chemical kinetics theory which successfully replicates this observation and provides insights into the processes responsible for these dynamics. The chemical kinetics theory combines the law of mass action, von Smoluchowski's diffusion-limited chemical reaction theory, and Eyring's transition state theory. This new theory reveals that the thermally reversible enzyme denaturation ensured by the ceaseless thermal motion of molecules and ions in an enzyme solution explains the plateau and subsequent decrease in chemical reaction rates with increasing temperature. The temperature-dependent affinity parameter (K) that relates enzymes and substrates through their binding also affects the shape of the emergent temperature response. We demonstrate that with an increase in substrate availability, K shifts the optimal temperature, where reaction rates plateau, towards higher values. Further, we show that the chemical kinetics theory accurately represents 12 sets of published enzyme assay data and includes the popular mechanistic model by Ratkowsky et al. (2005) as a special case. Given its good performance and solid theoretical underpinning, we believe this new theory will facilitate the construction of more mechanistic-based environmental biogeochemical models.

Preparation of hydrophilic and antibacterial bifunctional PVDF ultrafiltration membrane based on pomegranate peel powder

Pomegranate peels are often regarded as waste products, despite its antibacterial properties and hydrophilic functional groups. In this work, varying concentrations (0, 0.05, 0.15, 0.2 and 0.5 wt%) of pomegranate peel powder (PPP) were doped into polyvinylidene fluoride (PVDF) ultrafiltration membranes (UF) as antimicrobial agents and hydrophilic modifiers. With increase in PPP concentration, the water contact angle (from 83° to 66°) and porosity (from 73% to 54%) of the membrane showed a decrease, while the water flux, mechanical strength, and elongation at break had a consistent pattern of first increase followed by subsequent decrease. The morphological characteristics, chemical composition and thermodynamic properties of the membranes were further analyzed by SEM, FTIR, TAG, and DSC respectively. Additionally, in comparison to the PVDF pure membrane, membranes containing PPP demonstrated a more pronounced inhibitory impact on E. coli, and when the concentration was 0.15 wt% (M2), the BSA rejection rate (93.72%) and water flux (734.7 L m−2 h−1) of the membrane reached the peak. In conclusion, this study proposes the consideration of a cost-effective, environmentally friendly UF membrane with hydrophilic and antibacterial dual function, highlighting the promising application of pomegranate peel as agricultural waste in the membrane industry.

Study on corrosion law of coiled tubing in high CO2 gas field

The corrosion rates of CT80 grade coiled tubing steel (CT80) and 2205 duplex stainless steel (2205DSS), as well as other attachments, were determined using the weight loss method in a high-temperature and high-pressure autoclave to simulate operational corrosion conditions. The rates were compared with the predicted rates based on BP (backpropagation) neural network optimized by genetic algorithm, in response to the severe corrosion issue encountered during coiled tubing operations in high CO2 gas fields in Sichuan, China. In the gas phase, the results revealed that with the increase of the temperature and the CO2 partial pressure in the high CO2 gas field, the corrosion rate of CT80 gradually increases, while the rate of 2205DSS remains relatively stable and lower than that of CT80. In the liquid phase, the corrosion rate of CT80 exhibits an initial increase followed by a subsequent decrease with increasing temperature and partial pressure, while the 2205DSS corrosion rate remains slightly low and fairly stable. Furthermore, the XRD results of the corrosion product in the liquid phase revealed a higher corrosion rate on CT80 due to its loose and porous film structure, with FeCO3 and Fe2O3 being the main corrosion products. In contrast, 2205DSS exhibited only slight corrosion, characterized by a denser corrosion product film primarily composed of Cr2O3. The average error between the measured values and model calculated values is ∼15%, indicating that 2205DSS exhibited better wear resistance, making it suitable for application in the high CO2 gas field.

Effect of partial substitution of barium oxide by lanthanum oxide on the structure and properties of iron-based aluminosilicate glass

Silica-aluminum borates (SiO2-R2O3-R2O-RO-ZrO2 system) with La2O3 replacing BaO were preparing using the conventional melt quenching process. The impact of substituting BaO with La2O3 on the glass structure was examined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Raman. The density, thermal properties, alkali resistance and dielectric properties of the glasses were measured and compared using Archimedes, Differential Scanning Circuit (DSC), Thermal Expansion Calorimetry (TEC), Weight Reduction and Impedance Spectroscopy. The viscosity of the glass system was calculated from the thermal properties and discussed in comparison with the wetting angle at 1000 °C. The results showed that the glass does not undergo precipitation. With the increase of La2O3 to BaO substitution, the Q4 in the glass network structure transforms to Q0+Q1 and Q2, causing depolymeriation of the glass structure. This results in an increase in the density of the glass, as well as an increase and subsequent decrease in the thermal expansion coefficient. Additionally, the glass transition temperature and glass softening temperature decrease and then increase, which was due to the high field strength of La3+. When substituting 5 wt% of BaO with La2O3, The glass displayed the lowest dielectric constant and dielectric loss, along with the best alkali resistance. Viscosity calculations showed that the viscosity gradually increases at 1000 °C with the increase of La2O3 substitution, which was consistent with the wettability results. The glass components in the 0-5 wt% weight range all satisfy the iron-sealed glass wetting angle requirements.

СРАВНИТЕЛЬНЫЙ АНАЛИЗ УРОВНЯ ИНФОРМИРОВАННОСТИ СТАРШЕКЛАССНИКОВ И СТУДЕНТОВ МЕДИЦИНСКОГО ВУЗА В ВОПРОСАХ СОЦИАЛЬНО-ЗНАЧИМЫХ ЗАБОЛЕВАНИЙ И ПРОФИЛАКТИКИ ИППП

As is known, the sexually transmitted infection (STI) incidence continues to be a pertinent issue: high contagiousness and negative impact on public health puts STIs on the list of socially significant diseases. The consequences of these diseases directly affect the demographic situation in the country, due to the deterioration of the reproductive health of the population with a subsequent decrease in the birth rate. This issue becomes especially pronounced among teenagers. This paper demonstrates the results of a study on socially significant diseases and STI prevention issues conducted among high school and medical students in Moscow with the aim of studying and identifying youth awareness problems, differentiating the knowledge of STI prevention among high school and college students, as well as determining respondents’ interest in getting information on these diseases online. Purpose: To study and identify problems of youth awareness, determine the difference in the knowledge of STI prevention among the high school and college students, as well as determine the interest of respondents in obtaining information on these diseases online. Materials and methods of research: The study includes the results of anonymous questionnaires filled out by schoolchildren of 15-17 years (115 respondents) and 3rd year students of the Faculty of Medicine (134 respondents). Research methods: analytical, statistical, sociological. Results: Based on the research data, we identified a difference in the answers of schoolchildren and college students in several types of questions. Thus, medical school students clearly appear as more mature, independent and busy people with more extensive knowledge on the given topics. The vast majority of respondents showed interest and wanted to obtain information on socially significant diseases and STI prevention. The best way to do so is to communicate comprehensive, high-quality knowledge of socially significant diseases and STI prevention using online technologies.

Maternal autonomy support and intrusive control in the United States and China: Moment-to-moment associations with preschoolers' agency and defeat.

This study examines the moment-to-moment within-person associations between maternal and child behaviors during a challenging puzzle task and compares these associations between mother-child dyads from the United States (n = 99, 52 boys, Mchild age = 56.05 months, SD = 6.44) and China (n = 101, 46 boys, Mchild age = 57.41 months, SD = 6.58). Maternal autonomy support and intrusive control and child agency and defeat were rated in 15-s intervals by native and bicultural coders. Country was examined as a moderator of the moment-to-moment within-person associations between maternal and child behaviors. The results showed that for both U.S. and Chinese dyads, increases in maternal intrusive control predicted subsequent decreases in child agency, and increases in child defeat predicted subsequent increases in maternal autonomy support. Furthermore, increases in maternal autonomy support predicted subsequent increases in child defeat, but for the Chinese dyads only. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Design and performance optimization of diesel engine waste heat recovery methanol reforming hydrogen generation system

Abstract A shell-and-tube Methanol Steam Reformer (MSR) system was designed for diesel engines. The effects of structural and operational parameters of the spiral baffles in the methanol reformer on heat transfer and hydrogen production performance were investigated. Additionally, a multi-objective optimization using response surface methodology was conducted to study the interactive effects of spacing and thickness, as well as liquid hourly space velocity and steam–methanol ratio, on the methanol conversion rate, hydrogen concentration and hydrogen production. The results indicated that reducing the baffle spacing and increasing the baffle thickness further improved heat transfer efficiency. Optimal conditions were achieved at a spacing of 30 mm and a thickness of 2 mm, resulting in a methanol conversion rate of 64.2 %. Increasing the steam–methanol ratio from 0.5 to 2 increased the methanol conversion rate from 50.6 % to 79.7 %, with a subsequent decrease in hydrogen concentration. Increasing the liquid hourly space velocity from 635 h−1 to 1905 h−1 significantly reduced the methanol conversion rate from 94.5 % to 64.2 %, but the hydrogen production increased from 0.111 mol/s to 0.228 mol/s. Optimization results indicate that the liquid hourly space velocity and steam–methanol ratio have a greater influence on the hydrogen production efficiency of the methanol reformer.

Kinetic and adsorption isotherm studies of Malachite Green dye onto surfactant-tailored alginate hydrogel beads: An influence of surfactant hydrophobicity

This study details the synthesis and characterization of surfactant-modified sodium alginate hydrogel beads crosslinked with Ba2+ ions through ionotropic gelation. Cationic surfactants such as, dodecyltrimethylammonium bromide (DTAB), didodecyldimethylammonium bromide (DDAB), and butanediyl-α,ω-bis-(dimethyldodecylammonium bromide) (GEM), were employed in the modification process. The surfactant-modified ALG-DTAB, ALG-DDAB, and ALG-GEM beads were investigated for the removal of cationic dye Malachite Green (MG) to elucidate the impact of hydrophobicity of amphiphiles on the adsorption process. The characterizations were carried out using Rheometry, Field Emission Scanning Electron Microscopy (FESEM), Infrared Spectroscopy (IR), and Energy Dispersive X-ray Spectroscopy (EDX). Under optimized conditions, ALG-GEM and ALG-DDAB demonstrated highest maximum adsorption capacity (Qmax > 700 mgg−1). The adsorption data fitted well to pseudo-second order kinetic and Langmuir adsorption models, suggesting the involvement of chemisorption phenomena with notable contributions from pore diffusion. The effects of pH, initial dye concentration, adsorbent dose, temperature, and competing ions on the removal of MG were investigated. Interestingly, ALG-GEM beads exhibited an increase in adsorption capacity with rising pH and a subsequent decrease with increasing temperature, showcasing optimal adsorption at pH 7.0 and 25 °C. The study proposes that ALG beads modified with cationic surfactants with higher hydrophobicity could offer a promising avenue in wastewater treatment processes.

Decreased transport of nano- and micro-plastics in the presence of low-molecular-weight organic acids in saturated quartz sand

Low-molecular-weight organic acids (LMWOAs) and nano- and micro-plastics (NPs and MPs) are both widely distributed in terrestrial systems. To better understand the influence of LMWOAs on the transport of NPs and MPs, the effects of 0.5 mM citric- (CA), malic- (MA), and tartaric- (TA) acid on the transport of nano- (0.51 μm, PS NPs) and micro- (1.1 μm, PS MPs) polystyrene particles (2 mg L−1) in saturated quartz sand were investigated. All three LMWOAs decreased the transport of PS NPs and MPs, regardless of ionic composition or strength (0.1–10 mM NaCl and 0.1–1 mM CaCl2). Further investigation revealed that the interfacial interactions between PS-quartz sand surfaces and PS-PS were altered by LMWOAs. LMWOAs adsorbed to quartz sand surfaces could serve as new deposition sites, as evidenced by the decreased transport of PS NPs and MPs in quartz sand that was subjected to pre-equilibration with selected MA, the low inhibition of PS transport with low concentrations of LMWOAs (0.1 mM), and also the adsorption of LMWOAs onto quartz sand surfaces by batch experiments. Meanwhile, the adsorption of LMWOAs on PS, hydrodynamic measurement and visual TEM observation together clarified the slight aggregation of PS NPs and MPs in suspensions, inducing the subsequent decrease in transport. Among them, the adsorption of LMWOAs onto quartz sand surfaces was found to be the main factor dominating the decreased transport of both PS NPs and MPs in saturated quartz sand.

The impact of high temperature on mechanical properties and behaviors of sandstone

The impact of high temperature environments on the physical and mechanical properties of rocks is a significant factor to consider. The investigation into the impact of elevated temperatures on the physical and mechanical characteristics of rocks holds great importance in the advancement and exploitation of deep-seated mineral reserves, as well as in ensuring the safety and stability of subterranean engineering projects. This study utilizes the state-of-the-art GCTS Mechanical Loading Test System to conduct uniaxial and triaxial compression tests on sandstone after thermal treatment from 25°C to 650°C. In addition, XRD, SEM and nuclear magnetic resonance experiments were carried out on the sandstone after thermal treatment. The aim of the experiments is to provide a quantitative characterization of mechanical properties and behaviors of the rock samples. The results show that the mass, density, and wave velocity of sandstone decrease with increasing temperature, while volume and porosity increase. The mass, volume, and rate of density change of sandstone exhibit a significant increase when subjected to temperatures above 500°C. The uniaxial compressive strength and elastic modulus exhibit an initial increase followed by a subsequent decrease as the temperature rises, with 300°C serving as the critical turning point. The axial peak strain and Poisson’s ratio increase with increasing temperature. The cohesion decreases with increasing temperature, while the internal friction angle increases. Additionally, it is observed that the rate of change for both properties exhibits an increase beyond the temperature threshold of 400°C.

Contributions of Chinese hamster ovary cell derived extracellular vesicles and other cellular materials to hollow fiber filter fouling during perfusion manufacturing of monoclonal antibodies.

Hollow fiber filter fouling is a common issue plaguing perfusion production process for biologics therapeutics, but the nature of filter foulant has been elusive. Here we studied cell culture materials especially Chinese hamster ovary (CHO) cell-derived extracellular vesicles in perfusion process to determine their role in filter fouling. We found that the decrease of CHO-derived small extracellular vesicles (sEVs) with 50-200 nm in diameter in perfusion permeates always preceded the increase in transmembrane pressure (TMP) and subsequent decrease in product sieving, suggesting that sEVs might have been retained inside filters and contributed to filter fouling. Using scanning electron microscopy and helium ion microscopy, we found sEV-like structures in pores and on foulant patches of hollow fiber tangential flow filtration filter (HF-TFF) membranes. We also observed that the Day 28 TMP of perfusion culture correlated positively with the percentage of foulant patch areas. In addition, energy dispersive X-ray spectroscopy-based elemental mapping microscopy and spectroscopy analysis suggests that foulant patches had enriched cellular materials but not antifoam. Fluorescent staining results further indicate that these cellular materials could be DNA, proteins, and even adherent CHO cells. Lastly, in a small-scale HF-TFF model, addition of CHO-specific sEVs in CHO culture simulated filter fouling behaviors in a concentration-dependent manner. Based on these results, we proposed a mechanism of HF-TFF fouling, in which filter pore constriction by CHO sEVs is followed by cake formation of cellular materials on filter membrane.

Enhanced microbubble-mediated cavitation by using acoustic droplet vaporization

Acoustic cavitation serves various therapeutic purposes, with both microbubbles and phase-transit droplets serving as potential cavitation nuclei. This project focused on investigating the intricate interaction between microbubbles and droplets and the resultant impact on acoustic cavitation.To facilitate this investigation, microbubbles with a negative potential of −51.58 mV were prepared, while droplets were endowed with a positive potential of +4.22 mV, facilitating the formation of microbubble-droplet clusters. Microscopic analysis was employed to observe the morphology of these clusters, revealing an initial mean size of 4.85 µm before ultrasound activation and subsequent transformation into larger bubbles with a mean size of 12.54 µm after ultrasound activation. The experimental approach involved the use of varying driven voltages to generate ultrasound waves with different intensities. A passive cavitation detector (PCD) was then employed to capture cavitation signals. Results demonstrated that, when maintaining a microbubble ratio of 50% and varying droplet ratios from 0% to 50%, the driven voltage at which the cavitation peak appeared decreased from 180 mV to 140 mV. Additionally, the mean cavitation intensity exhibited an initial increase from 0.58 to 0.78, followed by a subsequent decrease from 0.78 to 0.63 after normalization.This study provided valuable insights into the dynamic interactions between microbubbles and droplets. Specifically, it showed that microbubble cavitation transferred energy to droplets, leading to the generation of larger bubbles and higher cavitation intensity. Nevertheless, the observed cavitation intensity and threshold were contingent upon the ratios of microbubbles and droplets. Notably, to achieve an ideal cavitation intensity, the energy generated by microbubble cavitation must be substantial enough to activate all droplets, inducing acoustic droplet vaporization (ADV) and cavitation.