Treatment Conditions Research Articles

Brain-derived neurotrophic factor modulation in response to oxidative stress and corticosterone: role of scopolamine and mirtazapine

Major Depressive Disorder (MDD) is a very complex disease, challenging to study and manage. The complexities of MDD require extensive research of its mechanisms to develop more effective therapeutic approaches. Crucial in the context of this disease is the role of brain-derived neurotrophic factor (BDNF) signaling pathway. AimThis manuscript aims to explore the complex relationship between MDD and BDNF signaling pathway, focusing on how BDNF is modulated in response to oxidative stress and corticosterone, known to be altered in MDD and contributing to the pathology of the disorder, when treated with scopolamine and mirtazapine. MethodsTo assess BDNF levels after the different treatment conditions, rat hippocampal slices and mice primary hippocampus and cortical cell culture were analyzed by immunofluorescence and Western blot. Key findingsBoth mirtazapine and scopolamine under stress conditions induced by hydrogen peroxide (H2O2) and corticosterone, had a significant impact on BDNF levels, and this was distinct in different neuronal models. Mirtazapine, especially when combined with H2O2, altered BDNF expression. Scopolamine when combined with both stressors also altered BDNF levels. However, its effects varied depending on the specific neuronal model and stress condition. In accordance with BDNF results, phosphorylated tropomyosin receptor kinase B (pTrkB) presented increased activation when neuronal cells subjected to stress were treated with mirtazapine or scopolamine. SignificanceCollectively, this study highlights the complex connection between these compounds, stress conditions, and BDNF/TrkB modulation, supporting the potential therapeutic effects of scopolamine and mirtazapine in modulating BDNF levels, even in stressful conditions.

Tribological and corrosion performance of duplex electrodeposited Ni-P/Ni-W-P coatings

The present research investigates the properties of duplex electrodeposited Ni-P/Ni-W-P coatings consisting of Ni-P and Ni-W-P as inner layers alternately. This study aims to examine how various heat treatment conditions affect the mechanical, tribological, and electrochemical properties of the coatings.The results show that the heat treatment temperature and duration have a profound influence on the coating’s microstructure, which significantly affects its overall performance. Optimal microhardness and lower wear rates are observed at 400 °C temperature for 1 h duration. However, at 800 °C for 4 h, duplex electrodeposited coatings display cracks and increased oxide layers, negatively impacting mechanical, tribological, and corrosion properties. The Ni-W-P outer layer coating exhibited higher hardness and a lower wear rate compared to the Ni-P outer layer coatings. However, the assessment of corrosion behavior shows that Ni-P offers increased corrosion resistance, largely due to its ability to form a passive layer, which is further enhanced after heat treatment. When compared to their individual single-layer coatings, the present duplex coatings demonstrate superior overall performance.

Functional activity and connectivity signatures of ketamine and lamotrigine during negative emotional processing: a double-blind randomized controlled fMRI study

Ketamine is a highly effective antidepressant (AD) that targets the glutamatergic system and exerts profound effects on brain circuits during negative emotional processing. Interestingly, the effects of ketamine on brain measures are sensitive to modulation by pretreatment with lamotrigine, which inhibits glutamate release. Examining the antagonistic effects of ketamine and lamotrigine on glutamate transmission holds promise to identify effects of ketamine that are mediated through changes in the glutamatergic system. Investigating this modulation in relation to both the acute and sustained effects of ketamine on functional activity and connectivity during negative emotional processing should therefore provide novel insights. 75 healthy subjects were investigated in a double-blind, single-dose, randomized, placebo-controlled, parallel-group study with three treatment conditions (ketamine, lamotrigine pre-treatment, placebo). Participants completed an emotional face viewing task during ketamine infusion and 24 h later. Acute ketamine administration decreased hippocampal and Default Mode Network (DMN) activity and increased fronto-limbic coupling during negative emotional processing. Furthermore, while lamotrigine abolished the ketamine-induced increase in functional connectivity, it had no acute effect on activity. Sustained (24 h later) effects of ketamine were only found for functional activity, with a significant reduction in the posterior DMN. This effect was blocked by pretreatment with lamotrigine. Our results suggest that both the acute increases in fronto-limbic coupling and the delayed decrease in posterior DMN activity, but not the attenuated limbic and DMN recruitment after ketamine, are mediated by altered glutamatergic transmission.

The potential of alkaline tolerant microbial consortia for textile wastewater treatment under integrated anaerobic/aerobic conditions: Performance evaluation and microbial community analysis

Sequential anaerobic/aerobic (A/O) treatment conditions for textile wastewater (WW) are more effective than conventional biological treatment. Anaerobic treatment is essential because anaerobic microbes can first break down complex and recalcitrant compounds, which are difficult to degrade under aerobic conditions. The simpler, more degradable compounds are then further broken down by aerobic microbes. This study aimed to evaluate the performance of a sequential A/O treatment process using a pilot-scale reactor to treat real textile WW and to characterize reactor and inoculum microbial community structures. The reactors were inoculated with microbial consortia originating from a diverse alkaliphilic soda lake in the Ethiopian Rift Valley. The WW test parameters were used to evaluate the performance of the treatment process. At steady state, the removal efficiencies were 97 % for dye, 86 % for Chemical Oxygen Demand (COD), and 93 % for Total Kjeldahl Nitrogen (TKN). Amplicon sequencing revealed that Firmicutes, Proteobacteria, and Actinobacteria were the dominant phyla in all the samples. Uncategorized microorganisms, followed by Alkalibacterium, Bifidobacterium, and Clostridium were the most abundant taxon in all the samples. The microbial community detected during the treatment process was not abundant in the inoculum originating from Lake Chitu, suggesting that the communities likely originated from textile WW. The textile WW treated with the integrated A/O process effectively degraded dyes, and the inoculated microbes demonstrated resistance to the toxic chemical composition of the WW. The integrated treatment process, along with the alkaliphilic microbial consortia, has proven to be practical for treating textile WW, offering valuable insights for field-scale applications.

Effects of atmospheric pressure plasma treatment and its aging behaviors on interfacial strength of PI/PEEK composite film

AbstractSince the properties of surface roughness with time and the wettability pattern of polymer surfaces transformed by plasma remain unclear. In order to understand the mechanism of aging effect on film properties, this paper analyzes the aging of plasma‐treated PI films. The optimal treatment conditions were first explored by adjusting the plasma treatment power. Based on the effect of plasma treatment power on the surface physicochemical properties and mechanical properties of PI films. It was found that the content of oxygen‐containing functional groups on the surface of the film was highest at a plasma treatment power of 800 W, and the surface energy reached a maximum value of 67.71 mJ/m2. As the treatment power increases, the surface etching of the PI film increases significantly, as does the roughness. However, if the power is too high, it can cause excessive etching, resulting in peeling of the film surface. In addition, the mechanical properties of the films decreased with increasing plasma treatment power. Based on the effect of plasma treatment power on the surface physicochemical and mechanical properties of PI films, the best overall modification effect of PI films was determined when the treatment power was 800 W and the speed was 6 mm/s. And at 800 W, the peel strength of the PI/PEEK composite film reached a maximum value of 9.55 N/cm, which was 77.84% higher than that of the untreated composite film. However, plasma‐treated PI films can experience surface remodeling after being exposed to air for a period of time. In this paper, the wettability as well as the mechanical properties of the films are analyzed for different aging times. The results showed that after 30 days of plasma treatment, the O/C and N/C contents on the surface of the PI film decreased, and the wettability performance decreased by 19.45% compared with that of the recently treated film.

Nebulized fentanyl does not improve exercise capacity or dyspnoea in fibrosing interstitial lung disease.

Exercise intolerance and exertional dyspnoea are hallmarks of fibrosing interstitial lung disease (FILD) and are associated with worse prognosis and quality of life. Activation of pulmonary vagal afferents influences the ventilatory pattern and contributes to the sensation of dyspnoea. We tested the hypothesis that nebulized fentanyl, which might attenuate aberrant pulmonary afferent activity in FILD, reduces ventilation and dyspnoea while extending exercise endurance time (EET). In this randomized, single-blind, placebo-controlled study, eight FILD patients (two males, 71±6years of age) performed incremental cardiopulmonary cycle exercise tests following nebulization of either fentanyl citrate (100 µg) or 0.9% saline. Previous work indicated that this dose was unlikely to produce central effects. Comparisons between treatment conditions at rest were undertaken using Student's paired t-test, and exercise data were evaluated with two-way ANOVA with repeated measures. Dyspnoea was assessed using the Borg dyspnoea scale. Resting respiratory variables were not different following treatment with fentanyl and saline; however, resting heart rate was lower following fentanyl (P=0.002) and remained lower throughout exercise compared with placebo (P=0.008). Fentanyl did not increase EET (placebo 334±117s vs. fentanyl 348±126s, P=0.250) although overall minute ventilation was reduced slightly (mean difference: -0.97 L/min, P=0.022). There were no differences in ratings of dyspnoea intensity or unpleasantness between the conditions either at rest or at end-exercise. Nebulized fentanyl did not improve EET or exercise dyspnoea but did decrease minute ventilation during exercise, although the extent of this reduction appears clinically insignificant. These findings suggest that nebulized fentanyl is unlikely to offer significant benefits for enhancing exercise capacity in FILD.

Caregivers on point: a randomized treatment–control prevention trial for foster and kinship caregivers to reduce behavior challenges among children in foster care

BackgroundChildren in foster care who are newly placed with licensed or kinship caregivers are often vulnerable to increased behavior problems associated with trauma and social disruptions. When those issues are not addressed, children are susceptible to placement disruptions that exacerbate behavior problems. Few preventive interventions are available for foster and kinship caregivers, and none are designed to be delivered at the time of a child’s placement into the home. This study aims to examine the impact of the Chicago Parent Program adapted and customized for foster and kinship caregivers (CPP-FC), locally branded as Caregivers on Point, on caregiver stress, parenting confidence and strategies, children’s behaviors, and placement stability.MethodsCaregivers (N = 300) are being recruited from a specialized foster care clinic that sees children and caregivers within five business days of a new placement. Upon completing baseline surveys and behavioral observation, caregiver-child dyads are randomized to receive CPP-FC (n = 150) or usual care (n = 150). Those in the treatment condition will complete 11 weekly sessions addressing child behavior management and caregiving approaches. A booster session will occur one month after the weekly sessions conclude. A mid-point assessment and behavioral observation will be collected four months after the baseline assessment for all participants, coinciding with the completion of the CPP-FC programming. At 6 months post-baseline, an end-of-study assessment will be collected. Administrative data will be extracted from the child welfare record to determine placement stability for the 12 months following enrolment. The primary outcome of interest is child behavior, indicated by changes in caregiver reports and objective ratings of behavior from observations, where raters are blinded to the treatment arm and timing of data collection. Secondary outcomes include placement stability and changes in caregiver stress and confidence in managing children’s behavior.DiscussionIf found to be effective, CPP-FC would be helpful for families involved with child welfare. It could be delivered by child welfare agencies, licensing and kinship navigator agencies, and foster care clinics and may be eligible for government reimbursement as a preventive intervention for children in foster care.Trial registrationThis study was prospectively registered with ClinicalTrials.gov, NCT06170047.

Risk of Hepatitis B Virus Reactivation in COVID-19 Patients Receiving Immunosuppressive Treatment: A Prospective Study.

Objectives: This study aimed to evaluate the risk of hepatitis B virus reactivation (HBVr) in COVID-19 patients receiving immunosuppressive treatment, which has been insufficiently studied to date. Secondarily, we aimed to evaluate the seroprevalence of HBV infection in COVID-19 patients. Methods: We performed HBV screening on all Romanian adults hospitalized in four COVID-19 wards between October 2021 and September 2022. We enrolled patients with positive hepatitis B core antibody (anti-HBc) without protective hepatitis B surface antibody (anti-HBs), HBV treatment, or baseline immunosuppressive conditions, and we conducted a virological follow-up on these patients at 3 months. Results: We identified 333/835 (39.9%) anti-HBc-positive patients. Follow-up was performed for 13 patients with positive hepatitis B surface antigen (HBsAg) and 19 HBsAg-negative/anti-HBc-positive patients. Among those who received immunosuppressants, 4/23 (17.4%) patients experienced HBVr: 1 out of 8 (12.5%) HBsAg-positive patients (with 1.99 log increase in HBV DNA level) and 3 out of 15 (20%) HBsAg-negative/anti-HBc-positive patients (with a de novo detectable HBV DNA level). Conclusions: Administration of COVID-19 immunosuppressants may result in a significant risk of HBVr in co-infected patients. We recommend performing an HBV triple screen panel (HBsAg, anti-HBs, anti-HBc) for all COVID-19 patients receiving immunosuppressive treatment. HBV prophylaxis may be indicated in certain patients. Larger studies are needed in order to establish appropriate and cost-effective management for these patients.

Microstructure, hardness, and creep of Co-Fe-Ni-based high-entropy superalloy processed by laser powder-bed fusion

A Co-Fe-Ni-based high-entropy superalloy (29Co-29Fe-29Ni-4.3Al-4.3Ti-4.3 V, at.%) designed to form a γ/γ′ microstructure was fabricated via laser powder-bed fusion, utilizing a blend of elemental powders. The hardness and microstructure were compared in terms of laser processing parameters, heat treatment conditions, and fabrication methods. Lower volumetric energy density (45 J/mm³) for fusion favor the formation of swirl-shaped, partially-mixed regions. The extent of elemental enrichment and depletion varies from region to region, even within the same sample. Upon direct aging of these inhomogeneous as-built samples, γ′ precipitates form along cell boundaries, which is attributed to strong segregation of Ni and Ti elements at these boundaries. After homogenization of the as-built samples, a uniform distribution of fine γ′ precipitates is achieved through aging. The hardness of a homogenized traditionally-cast sample is lower than that of an as-built sample, owing to differences in grain size. Nevertheless, both samples aged under the same conditions exhibited a similar level of hardness, attributed to strengthening by the γ′ phase.

Extraction of cellulose nanofibers from sugarcane bagasse at different hydrolysis conditions

This study investigated the effect of alkaline treatment and various acid hydrolysis conditions on the extraction of cellulose nanofibers from sugarcane bagasse. Alkaline treatments were conducted using sodium hydroxide and sodium hypochlorite solutions. After the alkaline treatment, acid hydrolysis was performed in solutions containing 60, 64, and 68% wt. of sulfuric acid at temperatures of 30 ± 1 °C and 45 ± 1 °C. The effectiveness of the alkaline treatment in removing non-cellulosic components was assessed by infrared spectrometry and scanning electron microscopy, which demonstrated satisfactory results in eliminating non-cellulosic components. Transmission electron microscopy revealed the impact of temperature on the dimensions of the extracted cellulose nanofibers, with acid hydrolysis at 45 °C yielding smaller nanofibers compared to hydrolysis at 30 °C. X-ray diffraction analysis showed a higher percentage of crystallinity for hydrolysis at 45 °C, which can be attributed to the removal of a substantial amount of amorphous cellulose content.

The Role of Generative Learning Strategy in Bridging the Gap between High and Low Achievers in Genetics Studies in Sefwi-Wiawso Municipality, Ghana

The study sought to investigate the use of the Generative Learning Strategy (GLS) in bridging the performance gap between high- and low-achieving students in genetics in Ghana's Western North region's capital, Sefwi-Wiawso Municipality. The study adopted an embedded research design involving the quasi-experimental pretest/posttest groups with a sample size of 106 SHS 3 Biology students. Two intact classes were randomly selected, treated as one group and exposed to the same treatment conditions. The Genetic Concepts Test and a semi-structured interview guide collected the quantitative and qualitative data, respectively. The GCT's internal consistency was 0.784, indicating a preferable internal consistency. The quantitative data was analyzed using the SPSS version 26, by employing descriptive and inferential statistics. The study found no significant performance difference between high and low achievers after using the GLS. The approach improved the lower achievers’ performance. The interview results revealed that Senior High School Biology students perceived that the Generative Learning Strategy improved the understanding, motivation, retention and self-directed learning of genetic concepts, thereby enhancing their learning outcomes. The study recommended that SHS Biology teachers employ the Generative Learning Strategy in teaching genetic concepts to bridge the performance gap between high and low achievers.

Evaluating the effectiveness of Smoke-Free Home SafeCare, an integrated intervention, among families at risk for secondhand smoke exposure and child maltreatment in the United States: a study protocol for a hybrid type 1 trial

BackgroundSecondhand smoke exposure (SHS) and child maltreatment (CM) are preventable yet have negative lifelong impacts on health. When considered together, the risk for negative health outcomes may be compounded, especially for people living in low-resource settings. Evidence-based interventions exist for preventing CM and reducing SHS among families with low resources; however, no programs jointly target SHS exposure and maltreatment risk.MethodsThis study is a hybrid type 1 trial to examine the effectiveness of a systematically braided intervention to target CM risk and SHS in the home. Fifty SafeCare Providers will be randomized to deliver either standard SafeCare (i.e., the SafeCare model alone; active treatment control; n = 25) or Smoke-Free Home SafeCare (SFHSC; treatment condition; n = 25), the braided intervention that includes both SafeCare and the Smoke-Free Homes: Some Things are Better Outside intervention to N = 500 families. Aim 2 is to assess family-level outcomes. The primary outcome is a full home smoking ban, validated by air nicotine monitors; secondary outcomes include parenting and smoking outcomes. Aim 3 is to evaluate process and implementation outcomes, including cost–benefit. We will use multilevel models and ROC analyses to evaluate and validate the primary outcome. We will use tests of non-inferiority to evaluate secondary outcomes. Cost-effectiveness analyses will be used to assess cost–benefit of SFHSC.DiscussionThis study will be the first to document the outcomes of a multi-component intervention to address cumulative risk factors that impact cancer risk among children whose parents are at risk or involved in child-protective services. Integrating an evidence-based intervention that targets SHS exposure in the home with a broadly disseminated CM prevention intervention may be a sustainable way to help reduce the compounded effects of SHS in the home and CM.Trial registrationClinicaltrials.gov, NCT05000632. Registered on August 11, 2021.

Improvements in Safety Outcomes Following Brief Healthcare-Based Intimate Partner Violence Interventions among Women Who Screen Positive for Intimate Partner Violence-Related Traumatic Brain Injuries.

Background: Traumatic brain injuries (TBIs) are a common consequence of experiencing intimate partner violence (IPV). IPV-related TBI contributes to adverse health outcomes among women, but it is unknown whether a history of IPV-related TBI negatively impacts safety outcomes following healthcare-based interventions for IPV. Methods: Using data from a larger randomized clinical trial, we explored the impact of IPV-related TBI status on safety-related outcomes in two healthcare-based IPV interventions. At baseline, 35% (n = 21) of the sample screened positive for IPV-related TBI history. We used repeated measures ANOVAs to examine differences in safety outcomes at post-treatment and 1-month follow-up based on treatment condition and IPV-related TBI status. Results: Significant interaction effects were found for safety outcomes, such that women with IPV-related TBI history experienced larger reductions in the frequency of physical IPV and similar reductions in sexual IPV across both treatment conditions compared to women without IPV-TBI (F(2, 102) = 10.88, p < 0.001; F(2, 98) = 3.93, p = 0.036). Conclusions: Findings suggest that brief healthcare-based IPV interventions may result in improvements in safety outcomes for women with a history of IPV-TBI. This highlights the continued need for implementation of promising IPV-focused interventions to promote safety and protect women from experiencing further IPV.

8245 Estradiol Interacts with the Val66Met Single Nucleotide Polymorphism in the Brain-Derived Neurotrophic Factor Gene to Alter Endometrial Thickness in a Rat Model

Abstract Disclosure: S. Moosa: None. E. Kohlmeir: None. S. Kujawa: None. D. Korol: None. A. Prakapenka: None. Brain derived neurotrophic factor (BDNF) is most known for its involvement in cell development, survival, and plasticity in the nervous system. BDNF and its cognate receptors can also be found in non-neural tissue including the ovary and uterus in humans and in animal models, suggesting that BDNF signaling may regulate reproductive functions. Indeed, disruptions in BDNF signaling are associated with health conditions related to the reproductive system, such as endometriosis. Studies show that treatment with estradiol increases expression of uterine BDNF and its cognate receptors, suggesting that estradiol can modulate BDNF signaling and its effects in the reproductive system. A common human functional single nucleotide polymorphism (SNP) in the BDNF gene, Val66Met (rs6265), is thought to decrease activity-dependent release of BDNF, altering BDNF signaling. Using a CRISPR/cas9 rat model of the human Val66Met BDNF SNP, we investigated the interacting role of estradiol and this variation in the BDNF gene on female uterine structure. Middle-aged (11-14-months-old) female rats were either homozygous for the Val allele (Val/Val; control) or the Met allele (Met/Met; BDNF SNP). All rats were ovariectomized and after three weeks randomly assigned to receive subcutaneous treatment of vehicle (sesame oil) or estradiol (17beta-estradiol benzoate) for two consecutive days. Twenty-four hours after the second injection, rats were euthanized and tissue collected, weighed, and placed in fixative. Uterine tissue weights differed significantly by treatment and by genotype such that uterine horns were heavier in estradiol-treated compared to vehicle-treated rats within each genotype and uterine horns were heavier in Met/Met compared to Val/Val rats within each treatment condition. To determine which uterine layer contributed to the weight differences, uterine horns were sectioned and stained with hematoxylin and eosin. Thickness of myometrium, endometrium, and lumen were individually measured. Although there were no treatment and no genotype effects on myometrial thickness, there were significant treatment and genotype effects on endometrial thickness. Of note, the endometrium of estradiol-treated Met/Met rats was thicker compared to vehicle-treated Met/Met rats and compared to estradiol-treated Val/Val rats, suggesting that estradiol and the BDNF gene variation interact to modulate endometrial size. Lumen circumference did not differ between genotypes but did increase with estradiol compared to vehicle treatment within each genotype. Altogether, findings suggest that BDNF genotype affects uterine structure, notably the endometrium. Differences with BDNF gene variation emerged with estradiol exposure, implicating the hormone’s role in modulating BDNF signaling and warranting future research on the interactive effects of estradiol and BDNF genotype on the endometrium. Presentation: 6/2/2024

8245 Estradiol Interacts with the Val66Met Single Nucleotide Polymorphism in the Brain-Derived Neurotrophic Factor Gene to Alter Endometrial Thickness in a Rat Model

Abstract Disclosure: S. Moosa: None. E. Kohlmeir: None. S. Kujawa: None. D. Korol: None. A. Prakapenka: None. Brain derived neurotrophic factor (BDNF) is most known for its involvement in cell development, survival, and plasticity in the nervous system. BDNF and its cognate receptors can also be found in non-neural tissue including the ovary and uterus in humans and in animal models, suggesting that BDNF signaling may regulate reproductive functions. Indeed, disruptions in BDNF signaling are associated with health conditions related to the reproductive system, such as endometriosis. Studies show that treatment with estradiol increases expression of uterine BDNF and its cognate receptors, suggesting that estradiol can modulate BDNF signaling and its effects in the reproductive system. A common human functional single nucleotide polymorphism (SNP) in the BDNF gene, Val66Met (rs6265), is thought to decrease activity-dependent release of BDNF, altering BDNF signaling. Using a CRISPR/cas9 rat model of the human Val66Met BDNF SNP, we investigated the interacting role of estradiol and this variation in the BDNF gene on female uterine structure. Middle-aged (11-14-months-old) female rats were either homozygous for the Val allele (Val/Val; control) or the Met allele (Met/Met; BDNF SNP). All rats were ovariectomized and after three weeks randomly assigned to receive subcutaneous treatment of vehicle (sesame oil) or estradiol (17beta-estradiol benzoate) for two consecutive days. Twenty-four hours after the second injection, rats were euthanized and tissue collected, weighed, and placed in fixative. Uterine tissue weights differed significantly by treatment and by genotype such that uterine horns were heavier in estradiol-treated compared to vehicle-treated rats within each genotype and uterine horns were heavier in Met/Met compared to Val/Val rats within each treatment condition. To determine which uterine layer contributed to the weight differences, uterine horns were sectioned and stained with hematoxylin and eosin. Thickness of myometrium, endometrium, and lumen were individually measured. Although there were no treatment and no genotype effects on myometrial thickness, there were significant treatment and genotype effects on endometrial thickness. Of note, the endometrium of estradiol-treated Met/Met rats was thicker compared to vehicle-treated Met/Met rats and compared to estradiol-treated Val/Val rats, suggesting that estradiol and the BDNF gene variation interact to modulate endometrial size. Lumen circumference did not differ between genotypes but did increase with estradiol compared to vehicle treatment within each genotype. Altogether, findings suggest that BDNF genotype affects uterine structure, notably the endometrium. Differences with BDNF gene variation emerged with estradiol exposure, implicating the hormone’s role in modulating BDNF signaling and warranting future research on the interactive effects of estradiol and BDNF genotype on the endometrium. Presentation: 6/2/2024

Effect of HIP on Creep Properties in the Single Crystal Superalloy

The Rene N5 is a second-generation single crystal superalloy containing 3wt% Re, commonly used in gas turbine blades for power generation at temperatures up to 1600°C due to its excellent creep life. Generally, single crystal (SX) and directionally solidified (DS) blades are not applied to hot isostatic pressing (HIP) because their porosities are lower than conventionally cast (CC) blades, and it causes recrystallization issue. However, in this study, HIP was chosen as a candidate to improve the mechanical properties of the second-generation single crystal superalloy Rene N5. HIP followed by ultra-rapid cooling rate of 660K/minute was applied in an attempt to address this issue. This approach was expected to enhance creep rupture properties through pore reduction and microstructural homogenization. Furthermore, by setting the HIP temperature and time identical to the solution treatment condition, the possibility of replacing solution treatment with HIP was discussed. As results of creep rupture tests, the rupture life was excellent in the order of specimens treated with HIP + solution + aging, solution + aging, and HIP + aging treatments. It is interesting that this is found to be primarily influenced by the size and shape of carbides and γ’ phases, with the effects of crystallographic orientation, shrinkage porosity, and eutectic phase being negligible.

Research on the corrosion protection of in-situ prepared Li[sbnd]Al layered double hydroxides on AZ31 Mg alloy under standard atmospheric pressure and low temperature

This work successfully prepared LiAl LDHs coatings on AZ31 Mg alloy under standard atmospheric pressure and low temperature. The whole process did not require a hydrothermal autoclave reactor and high pressure. Electrochemical test results showed that the coating was able to provide good corrosion protection performance. The LiAl LDHs coatings provided a large low-frequency impedance on AZ31. When the treatment time was 24 h, the maximum |Z|0.01Hz at pH = 12 was 5.14 × 104 Ω∙cm2, which is more than an order of magnitude higher than the |Z|0.01Hz of 1.81 × 103 Ω∙cm2 for the bare sample. Under the same treatment conditions, the potentiodynamic polarization test results showed that the LiAl LDHs coated samples had a lower corrosion current density and a higher breakdown potential. The icorr was 1.78 × 10−7 A/cm2 and Ebr was −0.82 VSCE compared to the Mg substrate (icorr of 1.13 × 10−5 A/cm2 and Ebr of −1.53 VSCE). Additionally, LiAl LDHs coatings also had a significant inhibitory effect on cathodic hydrogen evolution, providing targeted protection to the cathodic areas.

Heat Treatment Optimization and Nitriding Effects on Mechanical Properties of 32CrMoV12-10 Steel

32CrMoV12-10 steel is widely utilized in industries where high strength and toughness are crucial. This alloy is commonly used in manufacturing components like gun barrels, gears, and bearings, which demand exceptional mechanical properties. These parts typically undergo heat treatments, including hardening and surface enhancement techniques such as nitriding, to extend their fatigue life significantly. It is crucial to identify optimal heat treatment conditions to achieve desired material performance. In this study, commercial 32CrMoV12-10 steel was selected to investigate the impact of heat treatment parameters (temperature, duration time, and quenching media) on its mechanical properties. To analyse the effect of these parameters, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and the Taguchi Method were employed, facilitating a systematic examination of the process stages and subsequent mechanical testing outcomes, including Charpy V-notch impact, hardness, and tensile strength assessments. An optimal heat treatment protocol was established based on these analyses, and the nitriding depth of the optimally treated sample was examined using a micro-Vickers hardness tester. For comparative analysis, another sample with closely related outcomes was also evaluated. Results indicated that the surface hardness of the optimally treated Sample 10 reached 870 HV, with a core hardness of 417 HV, compared to non-nitrided Sample 3, which showed a surface hardness of 860 HV and a core hardness of 415 HV. Despite the proximity in their values, Sample 10 exhibited slightly higher micro-Vickers hardness than Sample 3. However, while Sample 3 fails to meet the specified tensile stress and hardness criteria, Sample 10, produced through optimization, meets criteria, ranging from 970 to 1040 N/mm², underscoring the efficacy of the optimization process facilitated by TOPSIS. This optimization was notable for its minimal experimental requirements, proving effective in conserving time, energy, and resources while investigating the processed material.

Integrating the Memory Support Intervention into the Transdiagnostic Intervention for Sleep and Circadian Dysfunction (TranS-C): can improving memory for treatment in midlife and older adults improve patient outcomes? Study protocol for a randomized controlled trial

BackgroundPoor memory for treatment is associated with poorer treatment adherence and poorer patient outcomes. The memory support intervention (MSI) was developed to improve patient memory for treatment with the goal of improving patient outcomes. The aim of this study protocol is to conduct a confirmatory efficacy trial to test whether a new, streamlined, and potent version of the MSI improves outcomes for midlife and older adults. This streamlined MSI is comprised of constructive memory supports that will be applied to a broader range of treatment content. The platform for this study is the Transdiagnostic Intervention for Sleep and Circadian Dysfunction (TranS-C). We will focus on midlife and older adults who are low income and experiencing mobility impairments.MethodsParticipants (N = 178) will be randomly allocated to TranS-C + MSI or TranS-C alone. Both intervention arms include eight 50-min weekly sessions. Assessments will be conducted at pre-treatment, post-treatment, 6-, and 12-month follow-up (6FU and 12FU). Aim 1 will compare the effects of TranS-C + MSI versus TranS-C alone on sleep and circadian functioning, daytime functioning, well-being, and patient memory. Aim 2 will test whether patient memory for treatment mediates the relationship between treatment condition and patient outcomes. Aim 3 will evaluate if previously reported poor treatment response subgroups will moderate the relationship between treatment condition and (a) patient memory for treatment and (b) treatment outcome. Exploratory analyses will compare treatment condition on (a) patient adherence, patient-rated treatment credibility, and patient utilization of treatment contents, and (b) provider-rated acceptability, appropriateness, and feasibility.DiscussionThis study has the potential to provide evidence for (a) the efficacy of a new simplified version of the MSI for maintaining health, well-being, and functioning, (b) the wider application of the MSI for midlife and older adults and to the treatment of sleep and circadian problems, and (c) the efficacy of the MSI for sub-groups who are likely to benefit from the intervention.Trial registrationClinicalTrials.gov NCT05986604. Registered on 2 August 2023.

Polysomnographically mediated cognitive improvements in individuals with insomnia symptoms following continuous theta-burst stimulation of the default mode network

IntroductionInsomnia is associated with mild cognitive impairment, although the mechanisms of this impairment are not well-understood. Timing of slow-wave and rapid eye movement sleep may help explain cognitive impairments common in insomnia. This investigation aimed to determine whether cognitive changes following continuous theta-burst stimulation (cTBS) are attributable to active stimulation, polysomnographic parameters of sleep, or both.MethodData presented here are part of a pilot clinical trial aiming to treat insomnia by targeting a node in the default mode network using an inhibitory 40-s (cTBS). A double-blind counterbalanced sham-controlled crossover design was conducted. Participants (N = 20) served as their own controls on two separate in-laboratory visits—one with active cTBS and the other with sham cTBS. Each visit included cognitive assessments before and after stimulation and following a night of sleep in the lab monitored with polysomnography.ResultsSlow wave sleep duration influenced working memory in the active cTBS condition, with shorter duration predicting improvements in working memory post sleep (B = −0.003, p = 0.095). Onset latency to rapid eye movement sleep predicted subsequent working memory, regardless of treatment condition (B = −0.001, p = 0.040). Results suggest that changes in attention and processing speed were primarily due to slow wave sleep onset (B = −0.001, p = 0.017) and marginally predicted by slow wave sleep duration (B = 0.002, p = 0.081) and sleep efficiency (B = 0.006, p = 0.090).ConclusionsFindings emphasize the important role that timing of slow-wave and rapid eye movement sleep have on information processing. Future work using larger sample sizes and more stimulation sessions is needed to determine optimal interactions between timing and duration of slow wave and rapid eye movement throughout the sleep period.Clinical trial registrationThis study is registered on ClinicalTrials.gov (NCT04953559). https://clinicaltrials.gov/study/NCT04953559?locStr=Arizona&amp;amp;country=United%20States&amp;amp;state=Arizona&amp;amp;cond=insomnia&amp;amp;intr=tms%20&amp;amp;rank=1