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Materials Horizons Jun 2024Reversible adhesion with on-demand attachment and detachment is used by many animals for their locomotion. However, achieving robust and switchable adhesion on rough...
Reversible adhesion with on-demand attachment and detachment is used by many animals for their locomotion. However, achieving robust and switchable adhesion on rough surfaces in artificial adhesives remains a significant challenge. Here, we present a snail mucus-inspired touch-initiate adhesive (TIA), showing robust adhesions on various surfaces. TIA is a polymeric hydrogel photo-cured with the presence of supersaturated sodium acetate (NaAc) in the precursor solution. TIA is soft and flexible at room temperature, allowing it to form conformal contact with objects with various surfaces. The contact with the target surface immediately initiates the crystallization of TIA, increasing the elastic modulus of TIA by an order of magnitude. The increased modulus and the interlocking with the target surfaces thus results in an adhesion strength up to 465.56 ± 84.05 kPa. TIA can be easily detached from the surface by heating to a temperature above 58 °C, showing an adhesion strength of 12.71 ± 2.73 kPa. The detached TIA, even cooled down to and kept at room temperature, is readily used for the subsequent adhesion. The study here not only provides a highly adhesive material for on-demand attachment to various surfaces, but also proposes a new design strategy to compose smart materials.
PubMed: 38932648
DOI: 10.1039/d4mh00331d -
Viruses Jun 2024Here, we report the discovery of two viruses associated with a disease characterized by severe diarrhea on a large-scale goat farm in Jilin province. Electron Microscopy...
Here, we report the discovery of two viruses associated with a disease characterized by severe diarrhea on a large-scale goat farm in Jilin province. Electron Microscopy observations revealed two kinds of virus particles with the sizes of 150-210 nm and 20-30 nm, respectively. Detection of 276 fecal specimens from the diseased herds showed the extensive infection of peste des petits ruminants virus (63.77%, 176/276) and caprine enterovirus (76.81%, 212/276), with a co-infection rate of 57.97% (160/276). These results were partially validated with RT-PCR, where all five PPRV-positive and CEV-positive specimens yielded the expected size of fragments, respectively, while no fragments were amplified from PPRV-negative and CEV-negative specimens. Moreover, corresponding PPRV and CEV fragments were amplified in PPRV and CEV double-positive specimens. Histopathological examinations revealed severe microscopic lesions such as degeneration, necrosis, and detachment of epithelial cells in the bronchioles and intestine. An immunohistochemistry assay detected PPRV antigens in bronchioles, cartilage tissue, intestine, and lymph nodes. Simultaneously, caprine enterovirus antigens were detected in lung, kidney, and intestinal tissues from the goats infected by the peste des petits ruminants virus. These results demonstrated the co-infection of peste des petits ruminants virus with caprine enterovirus in goats, revealing the tissue tropism for these two viruses, thus laying a basis for the future diagnosis, prevention, and epidemiological survey for these two virus infections.
Topics: Animals; Goats; Peste-des-Petits-Ruminants; Peste-des-petits-ruminants virus; Goat Diseases; China; Coinfection; Enterovirus Infections; Diarrhea; Enterovirus; Feces; Phylogeny
PubMed: 38932277
DOI: 10.3390/v16060986 -
Polymers Jun 2024While extensive research has focused on understanding the degradation mechanisms of Poly(vinyl acetate) (PVAC) paint under different environmental conditions, limited...
While extensive research has focused on understanding the degradation mechanisms of Poly(vinyl acetate) (PVAC) paint under different environmental conditions, limited attention has been paid to the long-term stability of PVAC-based white glues, especially when used in artworks. This study investigates the accelerated degradation, under simulated photoaging, and isothermal treatment of a commercial PVAC-based white glue considered representative of this class of materials used in contemporary artworks to predict its durability and assess its behavior in art objects. Through accelerated aging experiments and comparison with natural aging observed in artworks, the study reveals the formation of chromophores and the release of plasticizers as key processes; in particular, the progressive darkening was considered an early indicator of degradation processes, before structural changes could be detected by FTIR or NMR spectroscopies. The plasticizer loss induces an increase in glass transition temperature, from 7 °C to temperatures higher than room temperature, affecting the adhesive's cohesive strength and contributing to the detachment of materials in artworks. The findings underscore the importance of preventive conservation measures to mitigate degradation issues in PVAC-based artworks.
PubMed: 38932062
DOI: 10.3390/polym16121712 -
Polymers Jun 2024Clay minerals have different negative effects on the froth flotation process such as low adsorption of collectors on valuable minerals, increased pulp viscosity, and the...
Clay minerals have different negative effects on the froth flotation process such as low adsorption of collectors on valuable minerals, increased pulp viscosity, and the reduction in recovery and grade concentrates of copper sulfides. This study aims to evaluate the use of polystyrene-based nanoparticles (NPs) for the froth flotation of chalcopyrite and their ability to mitigate the negative effect of montmorillonite on the recovery of this sulfide. The experimental stage consisted of preparing a type of polystyrene-based nanoparticle (St-CTAB-VI), which was analyzed by dynamic night scattering (DLS) to establish its hydrodynamic size. Then, the effect of NPs on chalcopyrite's angle's in the presence and absence of montmorillonite (15%) was evaluated and compared with the contact angle achieved using potassium amyl xanthate (PAX) and a mixture of PAX and NPs. In addition, zeta potential measurements were carried out to investigate the interactions between the chalcopyrite and the montmorillonite or the NPs under fixed concentrations and microflotation tests were performed employing different times to evaluate the chalcopyrite recovery in the presence of montmorillonite, using NPs and mixtures with PAX. Finally, turbidity analysis as a function of time was performed to evaluate the occurrence of sedimentation and flocculation phenomena in suspensions of 15% montmorillonite in the presence and absence of chalcopyrite, nanoparticles, and mixtures of NPs and PAX. The results indicated that the mixture of NPs and PAX contributed to increasing the contact angle of chalcopyrite in the presence of montmorillonite. This can be associated with the presence of molecular and nanometric collectors that generated a higher hydrophobicity on the chalcopyrite particles, contributing to reducing the presence of clay minerals on the mineral surface. In addition, the mixture of NPs and PAX promoted the generation of nanoparticles on the sulfide mineral surface, which helps to detach the slime and facilitate the bubble/mineral attachment step during flotation.
PubMed: 38932032
DOI: 10.3390/polym16121682 -
Pharmaceutics Jun 2024Cancer represents a significant threat to human health. The cells and tissues within the microenvironment of solid tumors exhibit complex and abnormal properties in... (Review)
Review
Cancer represents a significant threat to human health. The cells and tissues within the microenvironment of solid tumors exhibit complex and abnormal properties in comparison to healthy tissues. The efficacy of nanomedicines is inhibited by the presence of substantial and complex physical barriers in the tumor tissue. The latest generation of intelligent drug delivery systems, particularly nanomedicines capable of charge reversal, have shown promise in addressing this issue. These systems can transform their charge from negative to positive upon reaching the tumor site, thereby enhancing tumor penetration via transcytosis and promoting cell internalization by interacting with the negatively charged cell membranes. The modification of nanocarriers with 2,3-dimethylmaleic anhydride (DMMA) and its derivatives, which are responsive to weak acid stimulation, represents a significant advance in the field of charge-reversal nanomedicines. This review provides a comprehensive examination of the recent insights into DMMA-modified nanocarriers in drug delivery systems, with a particular focus on their potential in targeted therapeutics. It also discusses the synthesis of DMMA derivatives and their role in charge reversal, shell detachment, size shift, and ligand reactivation mechanisms, offering the prospect of a tailored, next-generation therapeutic approach to overcome the diverse challenges associated with cancer therapy.
PubMed: 38931929
DOI: 10.3390/pharmaceutics16060809 -
Pharmaceutics May 2024Gastric acid secretion is closely associated with the development and treatment of chronic gastritis, gastric ulcers, and reflux esophagitis. However, gastric acid...
Gastric acid secretion is closely associated with the development and treatment of chronic gastritis, gastric ulcers, and reflux esophagitis. However, gastric acid secretion is affected by complex physiological and pathological factors, and real-time detection and control are complicated and expensive. A gastric delivery system for antacids and therapeutics in response to low pH in the stomach holds promise for smart and personalized treatment of stomach diseases. In this study, pH-responsive modular units were used to assemble various modular devices for self-regulation of pH and drug delivery to the stomach. The modular unit with a release window of 50 mm could respond to pH and self-regulate within 10 min, which is related to its downward floatation and internal gas production. The assembled devices could stably float downward in the medium and detach sequentially at specific times. The assembled devices loaded with antacids exhibited smart pH self-regulation under complex physiological and pathological conditions. In addition, the assembled devices loaded with antacids and acid suppressors could multi-pulse or prolong drug release after rapid neutralization of gastric acid. Compared with traditional coating technology, 3D printing can print the shell layer by layer, flexibly adjust the internal and external structure and composition, and assemble it into a multi-level drug release system. Compared with traditional coating, 3D-printed shells have the advantage of the flexible adjustment of internal and external structure and composition, and are easy to assemble into a complex drug delivery system. This provides a universal and flexible strategy for the personalized treatment of diseases with abnormal gastric acid secretion, especially for delivering acid-unstable drugs.
PubMed: 38931841
DOI: 10.3390/pharmaceutics16060717 -
Micromachines Jun 2024This study developed a novel dielectric wetting microfluidic operation platform combining parallel-plate and coplanar-plate regions with a curved surface structure as...
This study developed a novel dielectric wetting microfluidic operation platform combining parallel-plate and coplanar-plate regions with a curved surface structure as the connection structure. With the new electrowetting on dielectric (EWOD) platform, "droplet pull-out" has been successfully achieved and viewed as an essential new operation for microfluidics with the dielectric wetting technique. The EWOD system is divided into a PDMS substrate top plate and an indium tin oxide (ITO) glass substrate as a bottom layer on this chip. In the parallel-plate region, the droplets can be generated and transported through the square parallel electrodes; in the single-plate area, the droplets can be pulled out from the parallel structure, transported and mixed through the common grounded coplanar electrodes. In dielectric wetting performance testing, coplanar electrodes can apply a maximum driving force of 31.22 µN to DI water and 13.38 µN to propylene carbonate (PC). This driving force is sufficient to detach the sample from the top cover and pull the sub-droplet from the parallel plate structure for DI water, PC and polyethylene glycol diacrylate (PEGDA) buffer. The novel EWOD system also possesses the advantage of precise volume control for liquid samples; the volume error of the generated droplet can be controlled within 0.1% to 2%.
PubMed: 38930767
DOI: 10.3390/mi15060797 -
Microorganisms Jun 2024In September 2023, several hatcheries in Latin America experienced significant mortality rates, up to 90%, in zoea stage 2 of . Observations of fresh mounts revealed...
In September 2023, several hatcheries in Latin America experienced significant mortality rates, up to 90%, in zoea stage 2 of . Observations of fresh mounts revealed structures resembling lipid droplets, similar to those seen in a condition known as "las bolitas syndrome". Routine histopathological examinations identified detached cells and tissues in the digestive tracts of affected zoea, contrasting with the typical algal cell contents seen in healthy zoea. Polymerase chain reaction (PCR) testing for over 20 known shrimp pathogens indicated minimal differences between diseased and healthy batches. Both groups tested negative for acute hepatopancreatic necrosis disease (AHPND) but positive for species and Rickettsia-like bacteria in the diseased samples. Histological analyses of the affected zoea revealed characteristic tissue degeneration in the hepatopancreas, forming spheres that eventually migrated into the upper gut, midgut, and midgut caeca, a pathology identified as bolitas syndrome (BS). Microbiological assessments revealed species at concentrations of 10 CFU zoea/g in affected zoea, approximately two orders of magnitude higher than in healthy zoea. Bacterial isolation from both healthy and BS-affected zoea on thiosulphate-citrate-bile salts-sucrose (TCBS) agar and CHROMagar™ (Paris, France), followed by identification using API 20E, identified six strains of . Despite similarities to "las bolitas syndrome" in fresh mounts, distinct histopathological differences were noted, particularly the presence of sloughed cells in the intestines and variations in hepatopancreatic lobes. This study highlights the critical need for further research to fully understand the etiology and pathology of bolitas syndrome in zoea stage 2 of to develop effective mitigation strategies for hatchery operations.
PubMed: 38930568
DOI: 10.3390/microorganisms12061186 -
Journal of Clinical Medicine Jun 2024: To investigate anatomical and functional changes of the macula caused by epiretinal membrane (ERM) peeling procedures in patients with or without posterior vitreous...
: To investigate anatomical and functional changes of the macula caused by epiretinal membrane (ERM) peeling procedures in patients with or without posterior vitreous detachment (PVD). : This is a multicentric prospective observational study on thirty-seven (37) patients affected by symptomatic ERM who underwent 25-gauge pars plana vitrectomy (PPV), induction of a PVD (as needed) and peeling of both the internal limiting membrane (ILM) and ERM. Optical coherence tomography-angiography (OCT-A) (, Nidek, Japan) and microperimetry (, Nidek, Japan) were performed; central retinal thickness (CRT), foveal avascular zone (FAZ) area and perimeter, vessel density and perfusion density, retinal sensitivity and fixation stability (as a total mean retinal sensitivity (MRS), and MRS in the ellipse area and bivariate contour ellipse area (BCEA)) were recorded at baseline and up to postoperative month 3. : Eyes were classified as having complete PVD (51.4%) or incomplete PVD (48.6%). At baseline, patients with incomplete PVD had worse best-corrected distance visual acuity (BCDVA), total MRS, MRS in the ellipse area and BCEA, and higher CRT than patients with complete PVD. At month 3, the differences in BCDVA between the two groups remained statistically significant, with patients with incomplete PVD having worse results (difference: 0.199 logMAR, < 0.001). The difference in the MRS in the ellipse area was statistically significant at month 3 (-3.378 Db, = 0.035), with greater improvement in patients with complete PVD. : Our study shows that patients with incomplete PVD have worse conditions at baseline than patients with complete PVD, and the differences in visual acuity and retinal sensitivity were maintained postoperatively.
PubMed: 38930094
DOI: 10.3390/jcm13123565 -
Journal of Clinical Medicine Jun 2024: This study aimed to assess the effectiveness of bi-monthly brolucimumab treatment in patients with neovascular age-related macular degeneration (nAMD) refractory to...
: This study aimed to assess the effectiveness of bi-monthly brolucimumab treatment in patients with neovascular age-related macular degeneration (nAMD) refractory to monthly aflibercept treatment. : A retrospective chart review included 32 eyes of patients with refractory nAMD who switched from monthly intravitreal aflibercept treatment to bi-monthly intravitreal brolucizumab treatment. This study evaluated changes in visual acuity (VA), intraretinal fluid (IRF), subretinal fluid (SRF), pigment epithelial detachment (PED), and central macular thickness (CMT), at specific times as follows: baseline before switching (T0), 2 months after switching (T1), 4 months after switching (T2), and 6 months after switching (T3). : The mean best-corrected visual acuity (BCVA) did not significantly change across all time points (0.52 ± 0.12, 0.48 ± 0.27, 0.48 ± 0.28, and 0.50 ± 0.27 logarithms of the minimum angle of resolution in T0, T1, T2, and T3, respectively). CMT significantly decreased after additional brolucizumab injections compared to the baseline (218.2 ± 48.6 and 207.9 ± 49.8 μm, respectively; = 0.001). The PED height also significantly decreased from 251.0 ± 165.4 to 154.4 ± 115.65 μm ( < 0.001), with complete resolution in nine patients (28%). The mean subfoveal choroidal thickness (SFCT) before brolucizumab treatment was 262.8 ± 79.7 μm, which decreased to 233.0 ± 71.2 μm ( = 0.001) after the first injection. The final SFCT also significantly decreased after additional brolucizumab injections compared to the baseline SFCT ( = 0.012). : Bi-monthly brolucizumab treatment proves effective for patients refractory to monthly fixed aflibercept, resulting in positive anatomical changes without significant deterioration in visual acuity. This approach provides a promising prognosis while reducing the treatment burden on refractory patients.
PubMed: 38929964
DOI: 10.3390/jcm13123434