Poly Methyl Methacrylate Research Articles

Different essential oils can inhibit Candida albicans biofilm formation on acrylic resin by suppressing aspartic proteinase: In vitro and in silico approaches.

Cymbopogon martini, Syzygium aromaticum, and Cupressus sempervirens are used for antimicrobial purposes in the worldwide. Both their extracts and essential oil contents are rich in active ingredients. The aim of this study was to investigate the inhibitory effect of Cymbopogon martini essential oil (CMEO), Syzygium aromaticum essential oil (SAEO) and Cupressus sempervirens essential oil (CSEO) on Candida albicans biofilm formation on heat-polymerized polymethyl methacrylate (PMMA) samples in vitro and in silico. Essential oil contents with anticandidal potential were determined by Gas Chromatography-Mass Spectrometry. Following C. albicans adhesion, PMMA samples were treated independently with Corega® and each essential oil. The anticandidal activity of the essential oils was determined by spectrophotometric absorbance measurement at 600nm, taking into account the cultures of each sample. The cytotoxicity evaluation of essential oils was performed by MTT Colorimetric assay. The software package AutoDockTools (1.5.6) was used for the in silico studies. The effect of essential oil content on the inhibition of Secreted aspartic proteinase (SAP2) was evaluated considering the Ligand@SAP2 complex formation. 2% of CMEO and 5% of SAEO exhibited higher anticandidal activity than Corega® (p < 0.05), whereas Corega® had higher anticandidal activity than 2% and 5% of CSEO (p < 0.05). The cytotoxicity of essential oils on NIH/3T3 cells after 24h was found to be 2.41 for CSEO, 2.84 for CMEO, and 2.85µg/mL for SAEO. The results of the in silico study showed that citronellol from CMEO, chavibetol (m-eugenol) from SAEO and β-pinene from CSEO each had the highest effect on the inhibition of SAP2. The highest binding affinity value was found for citronellol at -5.3kcal/mol. The biofilm formation of C. albicans onto acrylic resin was inhibited by CMEO, SAEO and CSEO at a concentration of 2% through in vitro assay. The most effective inhibition was determined to be due to citronellol in CMEO through in silico analysis.

The impact of customized surface topography and porosity created by additive manufacturing technology on gingival fibroblasts.

The purpose of this study was to analyze gingival fibroblast proliferation on additively manufactured polymethylmethacrylate (PMMA) groups with different surface characteristics namely no treatment group (NTG) and customized 250µm diameter porosity (AM-250G) group. 3D-printed NTG was compared for its influence on growth of cells to a additively manufactured surface with porosity (AM-250G). For each group (NTG, AM-250G) 20 samples of material were tested. Fibroblast cells, at a concentration of 2.5×104cells/mL, were seeded into 48 plates separately into two groups (NTG, AM-250G). These were cultured in Dulbecco's Modified Eagle's Medium (DMEM) supplemented with 10% fetal bovine serum (FBS) at 37°C and 5% CO2 atmosphere. For cell proliferation MTT assay was conducted at 24, 48, and 72h. Cell proliferation was quantified through optical density (OD) measurements of the cell supernatant, and surface analysis was conducted using a scanning electron microscope (SEM). Data normality was confirmed by the Shapiro-Wilk test, with a significance level set at p<0.05. Statistical analysis was conducted using an independent Student's t-test at each time point. A significant difference in cell proliferation was observed at 24h, with the NTG group showing higher cell numbers compared to AM-250G group. Qualitative analysis of cell culture was performed using scanning electron microscopy to compare to the NTG and the porosity (AM-250G) groups after 24, 48, and 72h of fibroblast tissue attachment. No significant differences were observed between the groups at the 48 and 72-h intervals. At 24h, the NTG surface demonstrated superior cell proliferation compared to the surface with porosity (AM-250G). However, significant differences in cell growth on both materials at 48 and 72h, suggesting that both surface types eventually support similar levels of cell proliferation, with an increase of extensive spread and elongation of fibroblasts cells proliferation on the surface with porosity.

Facile Access to Highly Efficient 3D Printing Using Robust Self-Healing CDs/Polymer Hybrids.

3D printing efficiency, as a key indicator of additive manufacturing technology, directly affects its competitiveness in rapid prototyping, small batch production, and even large-scale industrial applications. Compared with traditional manufacturing methods, the high efficiency of 3D printing is often considered a bottleneck, hindering its application across various fields. Herein, a versatile and efficient strategy is proposed, namely, the dimensional reduction printing (DRP) process, to break the obstacle of high efficiency of 3D printing. Specifically, the self-healing CDs/PMMA nanocomposites were constructed via introducing carbon dots (CDs) synthesized by microfluidics into poly(methyl methacrylate) (PMMA) materials. Under the assistance of abundant hydrogen bonding and the entanglement of polymer chains, the fabricated CDs/PMMA nanocomposites exhibited outstanding self-healing properties, which can be utilized as ideal printing inks to achieve a highly efficient 3D printing process through assembling the printed simple 1D and 2D components into complex 3D models. We firmly believe that the DRP strategy opens up an idea for the design of a 3D printing process and points out the direction for the meaningful application of 3D printing technologies.

Chiral Resolution and Chiroptical Properties of Hindered Tetraphenylethylene Helicates.

Hindered tetraphenylethylene (hTPE) helicates are resolved into two left-handed (M) and right-handed (P) isomers by linkage and removal of chiral auxiliary (1R,2S,5R)-menthol, furnishing gram-scale hTPE enantiomers via flash silica column chromatography. hTPE helicate enantiomers bearing electron-accepting cyano and electron-donating triphenylamine groups can emit deep-blue CPL signals with a fluorescence quantum yield surpassing 50%. Full-color and white-light emission were achieved by blending them with dyes in a poly(methyl methacrylate) (PMMA) film.

Photophysical Investigation of Dyes and Dye-PMMA Systems: Insights into Absorption, Emission, and Charge Transfer Mechanisms.

The photophysical properties of five dyes, i.e., perylene, anthracene, aminoanthracene, 1,6-diphenylhexatriene, and 7-diethylamino-4-methylcoumarin, in solvent and attached to the poly(methyl methacrylate) (PMMA) polymer, were studied via DFT and TD-DFT calculations. Their absorption and emission spectra were calculated, while for the PMMA-dye systems, their absorption spectra were measured experimentally, in good agreement with the calculated ones. In the PMMA-dye systems, charge transfer from the dye to PMMA was observed, and in the case of perylene, electron transfer from its ground state was also observed. It was found that the PMMA-dye systems can interact photochemically via laser illumination, and provided that the charge transfer will be enhanced by using the appropriate laser parameters, the systems may be candidates for the design of materials for specific nanopatterning needs.

ОПЕРАТИВНАЯ КОРРЕКЦИЯ ДЕГЕНЕРАТИВНОГО ПОЯСНИЧНО-КРЕСТЦОВОГО СТЕНОЗА У СОБАК

The purpose of the study is to conduct a comparative evaluation of various methods for the correction of degenerative lumbosacral stenosis in dogs and to determine the most effective method. 32 dogs of various breeds and mestizos aged from one to 9 years were under observation. 8 dogs underwent surgery to correct degenerative lumbosacral stenosis by dorsal laminectomy followed by stabilization of L7-S1 screws 3.5–4.5 mm in diameter and polymethyl methacrylate. 24 dogs were operated on by the dorsal laminectomy method with the installation of the L7-S1 transpedicular system. Performing a dorsal laminectomy with L7-S1 stabilization with screws and bone cement is technically more difficult due to the impossibility of suturing the muscles over the metal structure, which in the early postoperative period is fraught with purulent complications due to the impossibility of creating a muscle frame over the cement fixator. In such cases, the risk of septic complications was significantly increased. Also, during revision operations, it becomes difficult to remove the cement and replace it if necessary. As a result of the studies, it was proved that dorsal laminectomy and installation of the L7-S1 transpedicular system ensures the disappearance of clinical signs of stenosis and rehabilitation of the animal in a shorter postoperative period, while providing unique opportunities for reoperation in cases of complications.

Polysiloxane-Modified PMMA-Shell Phase Change Microcapsules for Thermal Management Fabrics.

Critical issues such as leakage, degradation, and thermal response hysteresis have become the focus in the application of phase change materials (PCMs) in area such as thermal management of fabrics. The encapsulation of PCMs prepared as microcapsules using polysiloxanes, etc. as a component unit of crosslinking agents represents a highly promising avenue of research. In this work, organosilicon crosslinkers are prepared and employed for the crosslinking of poly (methyl methacrylate) (PMMA) for microencapsulation of paraffin wax in microcapsule phase change materials (mPCMs). The results showed that increasing the degree of crosslinking helps to improve the performance of mPCMs by smoothing the shell surface, but excessive crosslinking leads to flocculation, which reduces its performance. The mPCMs produced with 10%wt crosslinking agent gave the highest performance with encapsulation efficiency, melting enthalpy and crystallization enthalpy of 81.3%, 285.0 Jg-1 and 253.1 Jg-1, respectively. The obtained mPCMs are also combined with epoxy resin and fabrics to form composite materials. Notably, the polysiloxane-modified mPCMs permit epoxy resins to achieve a maximum temperature reduction of 25 °C. By adjusting the mass ratio of organosilicon crosslinkers, the obtained mPCMs enable textiles to reach a maximum temperature reduction of 17 °C while maintaining satisfactory air permeability.

Effect of Fluorophilic- and Hydrophobic-Modified Polyglycerol-Based Coatings on the Wettability of Low Surface Energy Polymers.

Catechol-derived polymers form stable coatings on a wide range of materials including challenging to coat low surface energy polymers. Whether modification of the coating polymer with fluorophilic or hydrophobic groups is a successful approach to further favor the coating of hydrophobic or fluorophilic surfaces with catechol-based polymers remains ambiguous. Herein, we report the effect of a series of catechol-derived polyglycerol (PG)-based coatings and monolayer coatings on the wettability of polytetrafluoroethylene (PTFE), polystyrene, and poly(methyl methacrylate) surfaces. Coatings with a longer hydrophilic PG block resulted in surface coatings with water contact angles (WCAs) around 60° independently of the modification and substrate, while coatings with a longer hydrophobic anchoring block possessed more diverse WCAs up to (129 ± 10)°. Despite the generally small impact of the fluorophilic modification for most substrate/coating combinations, some fluorophilic modified coatings reduce the WCA of PTFE below Berg's limit of 65°, indicating a shielding of fluorous segments from the surface.

Efficient Copolymerization of Methyl Methacrylate and Lactide Using Metalate Catalysts.

The development of catalysts that are both robust and highly active at room temperature can often be seen as a major challenge in anionic polymerization. However, these properties are desirable for polymer synthesis because they allow for easy and sustainable production of interesting materials. Here, iron and magnesium complexes are used to form in situ generated metalate complexes that are shown to be highly active in the room temperature copolymerization of methyl methacrylate and lactide. Their ability to form homopolymers and block copolymers of poly(methyl methacrylate) and polylactide shows that they are more stable than their organolithium counterparts and also more active than the neutral complexes from which they are derived.

РЕНТГЕНОЛОГИЧЕСКОЕ ОБОСНОВАНИЕ ЭФФЕКТИВНОСТИ ИСПОЛЬЗОВАНИЯ АНТИБАКТЕРИАЛЬНОГО СПЕЙСЕРА ПРИ СЕПТИЧЕСКОМ АРТРИТЕ ТАЗОБЕДРЕННОГО СУСТАВА У СОБАК

Purulent coxitis is one of the most common and severe complications of acute hematogenous osteomyelitis of the proximal end of the femur. Radiography remains the first-line imaging method for diagnosing and monitoring osteoarthritis due to its availability and low cost. The purpose of the study was to interpret radiographs of the hip joint in dogs with purulent coxitis using conservative and surgical treatment options. The basis for the treatment of purulent coxitis in dogs (n=15) in this study was radical surgical sanitation of the affected structures and suppression of the activity of bacterial infection using a special device – a hip joint spacer. The dogs of the first experimental group (n=5) were fitted with a reinforcing implant made of polymethyl methacrylate with an antibiotic (gentamicin). In the second experimental group (n=5), a two-component spacer made intraoperatively was used. The use of bone cement with the inclusion of an antibiotic contributed to its release over a long period of time and stopping the infectious process, which was recorded by X-ray images. The infectious process in the dogs of the control group was stopped quite slowly. Thus, destructive foci in the femoral head and acetabulum were observed on the 30th day; partial recovery was recorded in the dorsal edge of the acetabulum. By the 60th day of observation, the X-ray picture generally remained the same. Thus, by the 60th day after the operation, the acetabulum in dogs (n=5) of the first experimental group restored the lost structures, while in the second experimental group only two dogs showed positive dynamics by the 90th day of observation.

Evaluation of Polymethyl Methacrylate as a Provisional Material in a Fully Digital Workflow for Immediate-Load Complete-Arch Implant-Supported Prostheses over Three Months

While complete-arch digital-implant-scanning protocols have been described, their clinical outcomes when using polymethyl methacrylate (PMMA) as a provisional material remain insufficiently substantiated. This clinical study aims to integrate digital solutions into implant dentistry and establish PMMA as a reliable material for immediate-loaded protocols. Fifty-six patients received 432 implants and 72 immediate fixed interim complete-arch prostheses, all fabricated using a fully digital workflow. Patients were followed up at 3 months to evaluate implant survival, prosthesis survival, and implant mean marginal bone loss using an interim PMMA prosthesis. Patients completed the Oral Health Impact Profile (OHIP) questionnaire to determine the implants’ impact on quality of life. Statistical analyses included analysis of variance, Fisher’s least significant difference (LSD) test, and the Wilcoxon signed-rank test. Of the 432 implants placed, only two failures were observed. Marginal bone loss (MBL) was significantly greater in male patients (p = 0.002) and older smokers (p = 0.016). Patient-reported outcomes, as measured by the OHIP questionnaire, demonstrated significant improvements in quality of life. PMMA is a reliable material for immediate-loading protocols in fixed interim complete-arch implant prostheses. Its combination of mechanical strength, biocompatibility, and esthetic properties, along with the accuracy of fully digital workflows, ensures predictable clinical outcomes.

Microplastics in rivers of Gujarat (India) until the Arabian Sea: assessment of the sources, distribution and associated environmental risk.

Microplastics (MPs) have become a notable concern and are released into the environment through the disposal or fragmentation of large plastics. Rivers have been the major pathways for MPs present in the oceans, which significantly affects the marine environment. In the current study, water samples were collected from the upper stream and downstream of Damanganga and Tapi rivers across different sites in the state of Gujarat, India for exploration of MPs contamination. Additionally, samples were also collected from Dumas Beach to detect the presence of MPs. MPs were extracted from the samples through sieving, density separation and wet peroxide oxidation (WPO) techniques which were subsequently analyzed using μ-FTIR, optical microscope, Pyrolysis GCMS (Py-GCMS) and SEM. The concentration of MPs was also quantified from each stretch of Damanganga, Tapi rivers as well as Dumas Beach. Findings revealed that Damanganga showed a higher concentration (3.53 particles/L) of MPs as compared to others. Further, optical microscope and μ-FTIR analysis confirm the presence of MPs like Polypropylene (PP), Polystyrene (PS), Polyethylene terephthalate (PET), Polyethylene (PE) and Polymethyl Methacrylate (PMMA). Pyrolysis products of PP, PS and Polyamide (PA) were detected from Py-GCMS studies. Additionally, SEM images revealed that MPs were subjected to weathering, oxidation and atmospheric deposition over the years. The study additionally confirmed the flux of MPs in both the rivers and beach due to anthropogenic and industrial effects. Risk assessment of MPs was performed using the Pollutant Loading Index (PLI), which indicated that the overall MPs pollution in the studied sites was marginal. Nevertheless, the PLI scores revealed that Damanganga was the most prone to MP pollution among the three study sites.

The Role of Thermal Conductivity on Opposed Flow Flame Spread

ABSTRACT Quantifying the magnitude of solid-phase and gas-phase heat transfer for opposed flow flame spread has been the subject of research, and debate, for decades. Many studies neglect the contribution of longitudinal conduction through thermally thick solids for opposed flow flame spread. This study demonstrates the role of thermal conductivity with the addition of unidirectional conductive elements (copper, steel, and carbon fiber) in 12-mm-thick polymethylmethacrylate (PMMA) substrates. A layer of conductive elements was placed either or 3 or 6 mm from the surface of the solid. The addition of conductive elements in the direction of flame spread was found to increase the rate of both downward and lateral flame spread. The addition of copper elements in particular was found to increase the downward flame spread rate by nearly 60%. The subsequent increase in flame spread rate for each sample orientation (lateral and downward) was contextualized using the ratio of gas-phase and solid-phase heat transfer, as determined in previous studies. Additionally, the flame spread rate was correlated to the effective thermal conductivity in the longitudinal direction and the spread rate was found to follow an approximately linear relationship with effective thermal conductivity.

A Novel Tumor on Chip Mimicking the Breast Cancer Microenvironment for Dynamic Drug Screening

In light of the emerging breakthroughs in cancer biology, drug discovery, and personalized medicine, Tumor-on-Chip (ToC) platforms have become pivotal tools in current biomedical research. This study introduced a novel rapid prototyping approach for the fabrication of a ToC device using laser-patterned poly(methyl methacrylate) (PMMA) layers integrated with a polylactic acid (PLA) electrospun scaffold, enabling dynamic drug delivery and the assessment of therapeutic efficacy in cancer cells. Traditional drug screening methods, such as conventional cell cultures, mimic certain aspects of cancer progression but fail to capture critical features of the tumor microenvironment (TME). While animal models offer a closer approximation of tumor complexity, they are limited in their ability to predict human drug responses. Here, we evaluated the ability of our ToC device to recapitulate the interactions between cancer and TME cells and its efficacy in evaluating the drug response of breast cancer cells. The functional design of the proposed ToC system offered substantial potential for a wide range of applications in cancer research, significantly accelerating the preclinical assessment of new therapeutic agents.

Laminated Two-Terminal All-Perovskite Tandem Solar Cells with Transparent Conductive Adhesives.

Established sequential deposition of multilayer two-terminal (2T) all-perovskite tandem solar cells possesses challenges for fabrication and limits the choice of materials and device architecture. In response, this work represents a lamination process based on a transparent and conductive adhesive that interconnects the wide-bandgap (WBG) perovskite top solar cell and the narrow-bandgap (NBG) perovskite bottom solar cell in a monolithic 2T all-perovskite tandem solar cell. The transparent conductive adhesive (TCA) layer combines Ag-coated poly(methyl methacrylate) microspheres with an optical adhesive. The TCA is employed as a recombination junction, achieving self-encapsulation with high transparency and good conductivity. A high vertical electrical conductivity is realized by optimizing the distribution of microspheres using a novel solidification strategy that employs UV curing and drying at 85 °C at low pressure. In addition, uniform and dense bilayer hole transport layers are realized by vapor-phase evaporation, which facilitates the application of the TCA and achieves pinhole-free buried interfaces in both the WBG perovskite top solar cell and the NBG perovskite bottom solar cell. Using these two strategies, losses in fill factor (FF) and open-circuit voltage (VOC) of the 2T all-perovskite tandem solar cell are reduced, achieving a respectable power conversion efficiency up to 18.2% for the lamination of the all-perovskite tandem solar cell. The laminated tandem solar cell retains ∼93% of initial efficiency after exposure in ambient air (30-70 RH% and 20-35 °C) for ∼30 days.

Filtration flow rate at low convection volume in continuous hemodiafiltration using cytokine adsorbing hemofilter does not affect cytokine clearance in an experimental model

BackgroundIn recent years, continuous kidney replacement therapy (CKRT) with a cytokine adsorbing hemofilter (CAH) has been used in clinical practice to treat acute kidney injury associated with hypercytokinemia. Two types of CAH are available, including polymethyl methacrylate (PMMA) and polyethylenimine-coated polyacrylonitrile (AN69ST), each having distinct adsorption mechanisms. PMMA adsorbs substances with hydrophobic bases through hydrophobic interactions, resulting in occlusion of the membrane pores. AN69ST adsorbs positively charged substances through electrostatic bonds because its bulk layer is negatively charged. In both CAH, the adsorption efficiency of cytokines with large molecular weights is likely affected by filtration rather than by diffusion transfer. These adsorbing-type membranes have limitations in terms of filtration flow rate because of their low water permeability. The relationship between the adsorption effect and the filtration flow rate in CAH-CKRT has not been fully investigated.PurposeThe effect of low-convection volume settings below 600 mL/h on cytokine adsorption characteristics was experimentally investigated in CKRT.Materials and methodsTest solutions, including albumin (4.5%), creatinine (10 mg/dL), interleukin (IL)-6 (1000 pg/mL), and IL-8 (1000 pg/mL), were prepared. The test solution was circulated through the experimental circuit of continuous hemodiafiltration (CHDF) with a total convection volume ranging from 0 to 600 mL/h. The test solution was circulated through the experimental circuit of hemodiafiltration (CHDF) with various dialysate flow rates (QD; 0, 200, 400, and 600 ml/h) and filtration flow rates (QF; 0, 200, 400, and 600 ml/h). Samples immediately before and after CAH from the sampling port of the circuit were collected seven times at 1-min intervals. Clearances of creatinine, IL-6, and IL-8 were calculated for each setting of the proportions of QD and QF during CKRT using PMMA and AN69ST.ResultsCreatinine clearance increased with increasing QD and QF, regardless of the membrane type. There were no significant differences in the adsorption clearance of IL-6 and IL-8 among the different settings, regardless of the membrane type.ConclusionThe results of this study indicate that the cytokine clearance at a low convection volume in CAH-CKRT was not affected by the filtration flow rate.

Effective Thermal Conductivity of Nanofluids Containing Silicon Dioxide, Titanium Dioxide, Copper Oxide, Polystyrene, or Polymethylmethacrylate Nanoparticles Dispersed in Water, Ethylene Glycol, or Glycerol

The present study represents a continuation of our investigations on the effective thermal conductivity λeff of nanofluids by systematically varying the types of base fluids and particles. For the spherical nanoparticles with mean diameters between (20 and 175) nm, the metal oxides silicon dioxide (SiO2), titanium dioxide (TiO2), and copper oxide (CuO) as well as the polymers polystyrene (PS) and polymethylmethacrylate (PMMA) were selected to cover a broad range for the particle thermal conductivity λp from about (0.1 to 30) W⋅m–1⋅K–1. The corresponding polar base fluids water, ethylene glycol, and glycerol allow to not only vary their thermal conductivity λbf by a factor of more than two, but also their dynamic viscosity by about three orders of magnitude. For the measurement of λeff of the twelve different particle–fluid combinations, i.e., TiO2 or CuO with all three liquids as well as SiO2, PS, or PMMA with water or ethylene glycol, a steady-state guarded parallel-plate instrument (GPPI) associated with an expanded (k = 2) relative uncertainty between 0.022 and 0.032 was used at atmospheric pressure over a temperature range from (283 to 358) K at varying particle volume fractions up to 0.31. The results for the thermal-conductivity ratio λeff·λbf–1 are independent of temperature and show a moderate and relatively linear change as a function of the particle volume fraction. For similar ratios λp·λbf–1, the experimental data for λeff·λbf–1 are also very similar, which are above, close to, or below 1 if λp is larger than, comparable to, or smaller than λbf, respectively. For all nanofluids investigated, the Hamilton–Crosser model can describe the present measurement results and reliable experimental data reported in the literature for λeff·λbf–1 typically within ± 5 %. Overall, the measurement results from this work contribute to an extension of the database for λeff of nanofluids with respect to the investigated wide ranges of systems, temperature, and particle volume fraction.

Cement-Augmented Pedicle Screw Fixation in Patients with Osteoporosis : Safety, Efficacy and Complications.

Cement-augmented pedicle screw instrumentation is a widely accepted method for managing osteoporotic fractures, but it carries inherent risks, particularly related to cement leakage and embolism. This study aimed to analyze a clinical case of complications following cement fixation and provide a detailed review of relevant literature. A 70-year-old patient underwent transpedicular screw instrumentation from L2-L4 with polymethyl methacrylate augmentation, which resulted in cement leakage into the spinal canal and subsequent pulmonary embolism. After revision surgery and conservative treatment for the embolism, the patient's condition stabilized, demonstrating that conservative measures can be effective in managing cement embolism. To complement this case, a comprehensive literature review was conducted to explore the causes, prevention, and treatment of complications related to cement augmentation. The findings support that while cement-augmented pedicle screw instrumentation remains a leading technique for osteoporotic fractures, the associated risks are manageable with proper treatment protocols. This study holds practical significance for healthcare professionals by highlighting both the risks and solutions associated with cement fixation, thus contributing to improved patient outcomes and the development of standardized treatment guidelines.

Sensitization of Lanthanides with Metal Chalcogenides Nanocrystals: Night Vision Imaging and Security Encryption

AbstractThe sensitization of lanthanide ions by semiconductor nanocrystals offers promising potential for developing luminophores with high quantum yields, promising for light harvesting and imaging applications. This study introduces lanthanide‐doped CdS nanocrystals fabricated through a phosphine‐free method. Lanthanide ions such as Yb3+, Tm3+, Ho3+, and Er3+ are successfully doped into the CdS matrix, resulting in tunable NIR emissions ranging from 950 to 1600 nm. These nanocrystals exhibit visible–NIR emission with a total photoluminescence quantum yield of ≈41 ± 3%. Steady‐state and time‐resolved spectroscopic studies confirm the broadband sensitization of lanthanide ions by the CdS host. Binary ions‐doped CdS nanocrystals (CdS:Yb3+, Er3+/Ho3+/Tm3+) demonstrate both upconversion and downshifting processes within a single system. Furthermore, the NIR emission is enhanced under CdS excitation compared to direct lanthanide sensitization. Time‐resolved photoluminescence and transient absorption studies reveal the efficient energy transfer processes from CdS to the lanthanide dopants. Additionally, the NIR emission in CdS:Ln3+ embedded polymethyl methacrylate nanocomposites remains highly stable even months after fabrication, making them suitable for night vision imaging and security encryption. This study, therefore, advances the development of smart visible‐to‐NIR light sources for optoelectronic applications, including enhanced anti‐counterfeiting measures and night vision imaging.

"Mechanical Integrity Assessment of Polymethylmethacrylate Bone Cement Incorporating Local Anesthetics: Implications for Joint Arthroplasty".

Effective management of postsurgical pain following arthroplasty remains a challenge, lacking a definitive gold standard. As most knee and hip arthroplasties are cemented or hybrid, we used the property of bone cement as a drug carrier and added powdered local anesthetics (lidocaine hydrochloride and bupivacaine hydrochloride) to the polymethylmethacrylate (PMMA) as analgesics. However, the addition of drugs to bone cement may compromise its mechanical properties, necessitating a thorough analysis. Our objective was to assess the impact of added local anesthetics on the mechanical properties of PMMA bone cement. Mechanical properties, including compressive strength, bending modulus, and bending strength, were evaluated following the procedure set by the International Organization for Standardization (ISO) 5833-2002 and the American Society for Testing and Materials (ASTM) F451-1 standards. There were three study groups compared: PMMA, PMMA with lidocaine hydrochloride, and PMMA with bupivacaine hydrochloride. Significant differences were observed between groups in compressive and bending strength, but not in bending modulus. Despite these differences, the mean compressive strength and bending modulus of all groups and the mean bending strength of the lidocaine group surpassed the minimum values set by the ISO 5833-2002 and ASTM F 451-08 standards for acrylic bone cement. However, the bupivacaine group fell short of the minimum bending strength value. The addition of powdered local anesthetics to PMMA affects its mechanical properties, specifically compressive and bending strength, without compromising the bending modulus. While differences were noted, all groups surpassed the minimum standards for compressive strength and bending modulus. However, the bupivacaine group did not meet the minimum bending strength requirement. This highlights the importance of considering mechanical properties when incorporating drugs into bone cement for implant fixation.