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Soft Matter Sep 2023Frictional network formation has become a new paradigm for understanding the non-Newtonian shear-thickening behavior of dense suspensions. Recent studies have...
Frictional network formation has become a new paradigm for understanding the non-Newtonian shear-thickening behavior of dense suspensions. Recent studies have exclusively focused on interparticle friction that instantaneously vanishes when applied shear is ceased. Herein, we investigate a friction that emerges from dynamic chemical bridging of functionalized particle surfaces sheared into close proximity. This enables tailoring of both friction magnitude and the time release of the frictional coupling. The experiments use dense suspensions of thiol-functionalized particles suspended in ditopic polymers endcapped with benzalcyanoacetamide Michael-acceptors. The subsequent room temperature, catalyst-free dynamic thia-Michael reactions can form bridging interactions between the particles with dynamic covalent bonds that linger after formation and release in the absence of shear. This chemical friction mimics physical friction but is stickier, leading to tunable rheopexy. The effect of sticky friction on dense suspension rheology is explored by varying the electronic nature of the benzalcyanoacetamide moiety, the molecular weight of the ditopic polymers, the amount of a competitive bonding compound, and temperature. These results demonstrate how dynamic-bond-induced sticky friction can be used to systematically control the time dependence of the non-Newtonian suspension rheology.
PubMed: 37646285
DOI: 10.1039/d3sm00479a -
Neural Regeneration Research Apr 2024Glaucoma, characterized by a degenerative loss of retinal ganglion cells, is the second leading cause of blindness worldwide. There is currently no cure for vision loss... (Review)
Review
Glaucoma, characterized by a degenerative loss of retinal ganglion cells, is the second leading cause of blindness worldwide. There is currently no cure for vision loss in glaucoma because retinal ganglion cells do not regenerate and are not replaced after injury. Human stem cell-derived retinal ganglion cell transplant is a potential therapeutic strategy for retinal ganglion cell degenerative diseases. In this review, we first discuss a 2D protocol for retinal ganglion cell differentiation from human stem cell culture, including a rapid protocol that can generate retinal ganglion cells in less than two weeks and focus on their transplantation outcomes. Next, we discuss using 3D retinal organoids for retinal ganglion cell transplantation, comparing cell suspensions and clusters. This review provides insight into current knowledge on human stem cell-derived retinal ganglion cell differentiation and transplantation, with an impact on the field of regenerative medicine and especially retinal ganglion cell degenerative diseases such as glaucoma and other optic neuropathies.
PubMed: 37843215
DOI: 10.4103/1673-5374.381494 -
Cancer Immunology, Immunotherapy : CII Dec 2023This study examined the composition of the immune microenvironment at different sites within resected pancreas specimens from patients with pancreatic ductal...
This study examined the composition of the immune microenvironment at different sites within resected pancreas specimens from patients with pancreatic ductal adenocarcinoma (PDAC). Therefore, single-cell suspensions were made from fresh tumor and non-tumorous tissue. Fourteen patients were included from whom twelve PDAC and five non-tumorous samples were obtained. These samples were analyzed with a nineteen marker panel on the Aurora spectral flow cytometer. Furthermore, slides from formalin-fixed paraffine PDACs of eight additional patients were stained with eight markers and analyzed by multispectral imaging. These corresponded to central tumor, periphery of the tumor, i.e., invasive front and resected lymph node and were divided into tumor and adjacent tissue. In the single-cell suspension, a decreased ratio between lymphoid and myeloid cells and between M1 and M2 macrophages was observed in the tumor tissue compared to non-tumorous tissue. Furthermore, an increase in CD169 + macrophages in patients undergoing neoadjuvant therapy was found. Using immunofluorescence, more macrophages compared to T cells were observed, as well as a lower ratio of CD8 to M2 macrophage, a higher ratio of CD4-CD8 T cells and a higher ratio of immune-suppressive cells to pro-inflammatory cells in the PDAC area compared to the adjacent non-tumorous tissue. Finally, there were more immune-suppressive cells in the central tumor area compared to the invasive front. In conclusion, we show a gradient in the immune-suppressive environment in PDAC from most suppressive in the central tumor to least suppressive in distant non-tumorous tissue.
Topics: Humans; Tumor Microenvironment; Pancreatic Neoplasms; Carcinoma, Pancreatic Ductal; Pancreas; T-Lymphocytes
PubMed: 37938368
DOI: 10.1007/s00262-023-03573-6 -
Child Abuse & Neglect Aug 2023Exposure to family and domestic violence (FDV) in childhood can have a detrimental effect on children's health and social outcomes. However, research on the school...
BACKGROUND
Exposure to family and domestic violence (FDV) in childhood can have a detrimental effect on children's health and social outcomes. However, research on the school outcomes of children exposed to FDV is scant.
OBJECTIVES
To investigate the impact of FDV exposure on school attendance and suspension in Aboriginal and non-Aboriginal children.
METHODS
A population-based retrospective cohort study of school children, in grade 1 to 10, born from 1993 to 2006 in Western Australia (n = 26,743) using linked administrative data. Multivariate logistic regression analysis was used to calculate odds ratios and 95% confidence intervals to determine the association with school attendance and suspension outcomes for children exposed to FDV compared to non-exposed children.
RESULTS
Compared to non-exposed children, children exposed to FDV have an increase of poor school attendance: Aboriginal children adjusted odds ratio (aOR) = 1.91, 95% confidence interval (CI): 1.75-2.07, non-Aboriginal children aOR = 2.42, 95%CI: 2.12-2.75. FDV-exposed children also have an increased risk of school suspension: Aboriginal children aOR = 1.60, 95%CI: 1.47-1.74, non-Aboriginal children aOR = 2.68, 95%CI: 2.35-3.05, compared to non-exposed counterparts.
CONCLUSION
Exposure to FDV is associated with an increased odds of poor school attendance and school suspension. Evidence-based and innovative strategies are needed to support children who are exposed to FDV. This involves responding in ways that does not cause further trauma to children; a restorative and trauma-informed approach is vital.
Topics: Child; Humans; Retrospective Studies; Domestic Violence; Students; Schools; Exposure to Violence
PubMed: 35459527
DOI: 10.1016/j.chiabu.2022.105594 -
Medicina (Kaunas, Lithuania) Dec 2023While suspension training devices are increasingly gaining popularity, there is limited evidence on their effects on balance, and no comprehensive assessment has been...
While suspension training devices are increasingly gaining popularity, there is limited evidence on their effects on balance, and no comprehensive assessment has been conducted. This study aimed to evaluate the effects of a 9-session suspension training program on dynamic and static balance, stability, and functional performance. A total of forty-eight healthy adults, aged between 18 and 30, participated in a 9-session suspension training program. The program included exercises targeting upper and lower body muscles as well as core muscles. Balance was comprehensively assessed using various dynamic balance tests, including the Y Balance Test (YBT) as the primary outcome, single-leg Emery test, and sideways jumping test. Static balance was evaluated through the monopedal and bipedal Romberg tests. Changes from baseline were analyzed using a one-way ANOVA test. : Thirty-nine participants (mean age: 21.8 years) completed the intervention. The intervention resulted in significant improvements in YBT, jumping sideways, Emery, and 30s-SST scores ( < 0.001). Platform measures indicated enhanced monopedal stability ( < 0.001) but did not show a significant effect on bipedal stability ( > 0.05). : Suspension training is a safe and feasible method for improving dynamic balance and functional performance in healthy, untrained young adults. However, it does not appear to significantly impact the ability to maintain a static posture while standing.
Topics: Young Adult; Humans; Adolescent; Adult; Research; Analysis of Variance; Exercise; Exercise Therapy; Health Status; Suspensions
PubMed: 38256308
DOI: 10.3390/medicina60010047 -
Child Development 2023The study examined the impact of child protective services (CPS) contact on out-of-school suspensions for 49,918 Wisconsin students (followed from ages 5-6 to 14-15;...
The study examined the impact of child protective services (CPS) contact on out-of-school suspensions for 49,918 Wisconsin students (followed from ages 5-6 to 14-15; [school years 2010-2019; 74% White; 7% Black; 11% Hispanic; 8% other; 49% female]). A quasi-experimental design comparing recent CPS contact to upcoming (future) CPS contact shows that both recent CPS contact without foster care and future CPS contact predict higher odds of suspension compared with no contact. Higher odds of suspension emerged prior to CPS contact and did not substantially increase during or after CPS contact, suggesting that system-induced stress is not a primary driver of behavioral problems leading to suspension. Foster care reduced the odds of suspension among White children and children in special education.
Topics: Child; Female; Humans; Male; Child Protective Services; Child Welfare; Foster Home Care; Hispanic or Latino; Students; Child, Preschool; Adolescent; White; Black or African American; Wisconsin; Punishment; Schools; Social Isolation
PubMed: 37161769
DOI: 10.1111/cdev.13941 -
The International Journal of... Nov 2023Tablets are the most widely available dosage form for the treatment of TB; however, adult tablets fail to meet the needs of young children who cannot swallow these...
Tablets are the most widely available dosage form for the treatment of TB; however, adult tablets fail to meet the needs of young children who cannot swallow these tablets or require dose titration. We tested a new, simple device (XTEMP-R) and the methodology for converting tablets of TB drugs into a homogeneous suspension for home use by children and caregivers. XTEMP-R is a new device used for converting tablets into liquid preparations. Four TB drugs - pretomanid, delamanid, clofazimine and bedaquiline - were dispersed in the device utilizing water and simple syrup. The reproducibility of accurately delivering aliquots from the suspension upon preparation and upon redispersion after storing for 2 days was studied. Suspensions of each of the drugs tested were easily prepared in about 10 min and were visually uniform in consistency. Dosages in 2 and 5 mL were assessed in suspension, and those in 5 mL tested upon redispersion after 2 days. The observed range for these dosages spanned from 94.6% to 101.1% of the theoretical concentration for the suspensions under examination. The cleaned device had no detectable residual drug. XTEMP-R can be used at home by caregivers to prepare doses of suspensions accurately for children and patients who cannot swallow tablets.
Topics: Child; Adult; Humans; Child, Preschool; Reproducibility of Results; Tuberculosis; Tablets; Suspensions; Drug Stability
PubMed: 37880886
DOI: 10.5588/ijtld.23.0165 -
Materials (Basel, Switzerland) Oct 2023We investigated the effect of bioactive glass and zinc oxide nanoparticles on enamel remineralization, as well as their antimicrobial effect on cariogenic microbes. This...
BACKGROUND
We investigated the effect of bioactive glass and zinc oxide nanoparticles on enamel remineralization, as well as their antimicrobial effect on cariogenic microbes. This is the first study that investigated the properties of bioactive glass and zinc oxide nanoparticles with mixed materials.
METHODS
Fluoride gel (F), bioactive glass microparticles (µB), bioactive glass nanoparticles (nB), zinc oxide nanoparticles (Z), and a mixed suspension of nB and Z (nBZ) were prepared and characterized by scanning and transmission electron microscopy, zeta potential measurement, X-ray diffraction, and acid buffering capacity testing. Further, we performed a remineralization cycle test of 28 days, and nanoindentation testing was carried out during the immersion period, and then the enamel surfaces were examined using scanning electron microscopy. Additionally, the antimicrobial effects of the sample suspensions were evaluated by measuring their minimum microbicidal concentrations against various cariogenic microbes.
RESULTS
Our results revealed that nB had a near-circular shape with an amorphous structure and a considerably large specific surface area due to nanoparticulation. Additionally, nB possessed a rapid acid buffering capacity that was comparable to that of μB. In the remineralization test, faster recovery of mechanical properties was observed on the enamel surface immersed in samples containing bioactive glass nanoparticles (nB and nBZ). After remineralization, demineralized enamel immersed in any of the samples showed a rough and porous surface structure covered with mineralized structures. Furthermore, nBZ exhibited a broad antimicrobial spectrum.
CONCLUSIONS
These results demonstrated that bioactive glass and zinc oxide nanoparticles have superior demineralization-suppressing and remineralization-promoting effects.
PubMed: 37959475
DOI: 10.3390/ma16216878 -
Materials (Basel, Switzerland) Sep 2023Aqueous suspensions (colloids) containing detonation nano-diamond (DND) feature in most applications of DND and are an indispensable stage of its production; therefore,... (Review)
Review
Aqueous suspensions (colloids) containing detonation nano-diamond (DND) feature in most applications of DND and are an indispensable stage of its production; therefore, the interaction of DND with water is actively studied. However, insufficient attention has been paid to the unique physico-chemical and biological properties of transparent colloids with DND content (≤0.1%), which are the subject of this review. Thus, such colloids possess giant dielectric permittivity which shows peculiar temperature dependence, as well as quasi-periodic fluctuations during slow evaporation or dilution. In these colloids, DND interacts with water and air to form cottonwool-like fibers comprising living micro-organisms (fungi and bacteria) and DND particles, with elevated nitrogen content due to fixation of atmospheric N. Prolonged contact between these solutions and air lead to the formation of ammonium nitrate, sometimes forming macroscopic crystals. The latter was also formed during prolonged oxidation of fungi in aqueous DND colloids. The possible mechanism of N fixation is discussed, which can be attributable to the high reactivity of DND.
PubMed: 37763505
DOI: 10.3390/ma16186227 -
Amyotrophic Lateral Sclerosis &... Aug 2023To describe the clinical and demographic characteristics of patients with MND treated with riluzole by comparing two dosage forms (oral suspension and tablets), as well...
To describe the clinical and demographic characteristics of patients with MND treated with riluzole by comparing two dosage forms (oral suspension and tablets), as well as the impact on survival in patients with and without dysphagia according to the form of dosage. Retrospective and prospective cohort of patients diagnosed with MND at the multidisciplinary functional unit of Motor Neuron Disease in our center in the period between 1 of January 2011 and 31 of December 2020 ( = 742). A descriptive analysis (univariate and bivariate) was carried out and survival curves were estimated. During the follow-up period, 402 males (54.18%) and 340 females (45.82%) were diagnosed with MND. Of these patients, 632 (97.23%) were being treated with 100mg riluzole: 282 (54.55%) patients took this in tablet form and 235 (45.45%) oral suspension. Riluzole in tablet form is taken more frequently by men than women, in younger age ranges, and mostly without dysphagia (78.31%). Also, it is the predominant dosage form for classic spinal ALS and respiratory phenotypes. Dosages via oral suspension are taken by patients in the older age ranges (over 64.8 years), mostly with dysphagia (53.67%) and more frequently with bulbar phenotypes such as classic bulbar ALS and PBP. Because of this, patients using oral suspension (most of them with dysphagia) had a poorer survival rate (at 90% CI) than patients using tablets (most of them without dysphagia). The most appropriate dosage form should be given according to the patient's needs at each stage of the disease and, furthermore, oral suspension could improve adherence to treatment because it avoids having to change from one form (tablet) to the other (suspension) when swallowing disorders appear.
Topics: Male; Female; Humans; Riluzole; Amyotrophic Lateral Sclerosis; Neuroprotective Agents; Retrospective Studies; Prospective Studies; Deglutition Disorders
PubMed: 37009997
DOI: 10.1080/21678421.2023.2192247