Supertoughened Polylactic Acid/Polybutylene Adipate Terephthalate Blends Compatibilized with Ethylene-Methyl Acrylate-Glycidyl Methacrylate: Morphology and Mechanical Properties by the Response Surface Methodology.

Optimized extrusion melt-blending of polylactic acid (PLA) polymer with a minor biopolymeric phase, polybutylene adipate terephthalate (PBAT), and compatibilized with random ethylene-methyl acrylate-glycidyl methacrylate terpolymer (EMA-GMA, Trademark: Lotader AX-8900) led to an outstanding improvement in mechanical properties. At the noncompatibilized PLA-PBAT (80-20) blend point, significant enhancement (∼4500%) in toughness and elongation-at-break was already obtained without compromising any elastic properties. The effect of the compatibilizer content on the mechanical properties of the PLA-PBAT (80-20) blend was investigated by an optimal custom response surface methodology. Thus, 2 wt % Lotader content was determined to be optimal by a numerical optimization methodology with a desirability value, D, of 0.882 to maximize toughness and elongation-at-break. The compatibilization and thermal behavior of the Lotader-modified blends were analyzed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Upon adding the compatibilizer, the original phase-separated morphology of the blends changed from PBAT quasi-spherical domains to nearly elongated elliptical ones. It was also found that the interfacial boundary line of the domains faded away, which revealed that interfacial compatibility was achieved. The thermostability of the blends remained largely unaltered following the incorporation of PBAT and Lotader. Moreover, while PBAT exhibited a minor influence on the crystallinity of PLA, Lotader had no discernible impact on crystallinity, as evidenced by the DSC thermograms. Thus, the compatibilizer at the optimal point in the optimized blend ratio led to the formation of a phase-separated morphology that combined internal cavitation, interfacial cavitation, and strong adhesion features at the right proportions in the microstructure which underlies the micromechanisms driving the remarkable enhancement of as much as 7100% in toughness and ductility.

Polyurea/Aminopropyl Isobutyl Polyhedral Oligomeric Silsesquioxane-Functionalized Graphene Nanoplatelet Nanocomposites for Force Protection Applications.

Herein, the development of new nanocomposite systems is reported based on one-part polyurea (PU) and aminopropyl isobutyl polyhedral oligomeric silsesquioxane (POSS)-functionalized graphene nanoplatelets (GNP-POSS) as compatible nanoreinforcements with the PU resin. GNP-POSS was effectively synthesized via a two-step synthesis protocol, including ultrasonication-assisted reaction and precipitation, and carefully characterized with respect to its chemical and crystalline structure, morphology, and thermal stability. FTIR and XPS spectroscopy analyses revealed that POSS interacts with the residual oxygen moieties of the GNPs through both covalent and noncovalent bonding. The X-ray diffraction pattern of GNP-POSS further revealed that the crystallinity of the GNPs was not altered after their functionalization with POSS. GNP-POSS was successfully incorporated in PU at contents of 1, 3, 5, and 10 wt % to yield PU/GNP-POSS nanocomposite films. An ATR-FTIR analysis of these films confirmed the presence of strong interfacial interactions between the urea groups of PU and the GNP-POSS functionalities. Moreover, the PU/GNP-POSS nanocomposite films exhibited enhanced thermal stability and mechanical properties compared to those of the neat PU film. The quasi-static tensile testing of the PU/GNP-POSS samples revealed remarkable enhancements in the tensile strength (from 7.9 for the neat PU to 25.1 MPa for PU/GNP-POSS) and Young's modulus (238-617 MPa), while elongation at break and toughness also showed 14 and 125% improvements, respectively. Finally, the effects of GNP-POSS content on the morphological, quasistatic tensile, and high-strain-rate dynamic behavior of the PU/GNP-POSS nanocomposite films were also investigated. Overall, the tests performed using a split-Hopkinson pressure bar setup revealed a large increase in the film strength (from 147.6 for the neat PU film to 199 MPa for the PU/GNP-POSS film) and a marginal increase in the energy density of the film (38.1-40.8 kJ/m3). These findings support the suitability of the PU/GNP-POSS nanocomposite films for force protection applications.

Graphitic Carbon Nitride Quantum Dots (g-C3N4 QDs): From Chemistry to Applications.

Since their emergence in 2014, graphitic carbon nitride quantum dots (g-C3N4 QDs) have attracted much interest from the scientific community due to their distinctive physicochemical features, including structural, morphological, electrochemical, and optoelectronic properties. Owing to their desirable characteristics, such as non-zero band gap, ability to be chemically functionalized or doped, possessing tunable properties, outstanding dispersibility in different media, and biocompatibility, g-C3N4 QDs have shown promise for photocatalysis, energy devices, sensing, bioimaging, solar cells, optoelectronics, among other applications. As these fields are rapidly evolving, it is very strenuous to pinpoint the emerging challenges of the g-C3N4 QDs development and application during the last decade, mainly due to the lack of critical reviews of the innovations in the g-C3N4 QDs synthesis pathways and domains of application. Herein, an extensive survey is conducted on the g-C3N4 QDs synthesis, characterization, and applications. Scenarios for the future development of g-C3N4 QDs and their potential applications are highlighted and discussed in detail. The provided critical section suggests a myriad of opportunities for g-C3N4 QDs, especially for their synthesis and functionalization, where a combination of eco-friendly/single step synthesis and chemical modification may be used to prepare g-C3N4 QDs with, for example, enhanced photoluminescence and production yields.

Incorporation of g-C3N4 nanosheets and CuO nanoparticles on polyester fabric for the dip-catalytic reduction of 4 nitrophenol.

In the present work, we present the preparation of a new emerged heterogeneous catalyst (PE/g-C3N4/CuO) by in situ deposition of copper oxide nanoparticles (CuO) over the graphitic carbon nitride (g-C3N4) as the active catalyst and polyester (PE) fabric as the inert support. The synthesized sample (PE/g-C3N4/CuO) "dip catalyst" was studied by using various analytical techniques (Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy and dispersive X-ray spectroscopy (SEM/EDX), and transmission electron microscopy (TEM). The nanocomposite is utilized as heterogeneous catalysts for the 4-nitrophenol reduction in the presence of NaBH4, in aqueous solutions. According to experimental results, PE/g-C3N4/CuO with a surface of 6 cm2 (3 cm × 2 cm) demonstrated the catalyst exhibit excellent catalytic activity with 95% reduction efficiency for only 4 min of reaction and an apparent reaction rate constant (Kapp) of 0.8027 min-1. Further evidence that this catalyst based on prepared PE support can be a good contender for long-lasting chemical catalysis comes from the remarkable stability after 10 repetitions reaction cycles without a noticeably loss in catalytic activity. The novelty of this work consists to fabricate of catalyst based of CuO nanoparticles stabilized with g-C3N4 on the surface of an inert substrate PE, which results in an heterogenous dip-catalyst that can be easily introduced and isolated from the reaction solution with good retention of high catalytic performance in the reduction of 4-nitrophenol.

Low-dose or -number of BCG in non-muscle invasive bladder cancer: updated systematic review and meta-analysis.

Aim: We aimed to review the evidence of reducing the dose or number of BCG instillations in non-muscle invasive bladder cancer (NMIBC) patients. Material & methods: A literature search was done according to Preferred Reporting Items for Meta-Analyses statement. Results: Overall, 15 and 13 studies were eligible for qualitative and quantitative synthesis, respectively. In patients with NMIBC, lowering either the dose or number of BCG instillations increases the risk of recurrence, but not the risk of progression. Lowering the dose of BCG decreases the risk of adverse events compared with standard-dose BCG. Conclusion: Standard-dose and -number of BCG is preferred for NMIBC patients based on oncologic efficacy; however, low-dose BCG could be considered in selected patients who suffer from significant adverse events.

Doctors use a medicine called BCG to treat a kind of bladder cancer that hasn't spread to other parts of the body. But because there isn't enough of this medicine, scientists are looking at giving smaller amounts. They found that smaller amounts of the medicine have fewer side effects, but they also found that they might not work as well to stop the cancer from coming back. So, the regular amount of BCG is still the best option for most patients, but smaller amounts might be okay for some people who are worried about side effects. However, more research is needed to make sure it's safe and effective.

Impact of Performance Status on Oncologic Outcomes in Patients with Advanced Urothelial Carcinoma Treated with Immune Checkpoint Inhibitor: A Systematic Review and Meta-analysis.

CONTEXT: Immune checkpoint inhibitors (ICIs) are widely used in the management of patients with advanced urothelial carcinoma (aUC). However, its performance in aUC patients with poor performance status (PS) remains unknown. OBJECTIVE: We aimed to assess the impact of patients' performance status on the oncologic outcomes in patients with aUC treated with ICIs. EVIDENCE ACQUISITION: We searched PubMed, Web of Science, and Scopus from inception until July 2022 to identify studies assessing the association between the Eastern Cooperative Oncology Group (ECOG) PS and the oncologic outcomes in patients with aUC treated with ICIs in randomised (RCTs) and nonrandomised (NRCTs) control studies according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. The outcomes of our interests were overall survival (OS), cancer-specific survival (CSS), progression-free survival (PFS), and objective response rate (ORR). EVIDENCE SYNTHESIS: Overall, six RCTs comprising 5428 patients and 32 NRCTs comprising 6069 patients were included. The meta-analysis of the RCTs revealed that patients with ECOG PS = 0 and PS ≥1 had a trend towards better OS with ICIs compared with those treated with chemotherapy (pooled hazard ratio [HR]: 0.86, 95% confidence interval [CI]: 0.71-1.04, and HR: 0.74, 95% CI: 0.53-1.03, respectively). There was no significant difference in terms of response to ICIs between patients with poor and good PS (I2 = 0%, p = 0.46). The meta-analysis of the NRCTs revealed that patients with PS ≥2 had significantly worse OS than those with PS <2 (pooled HR: 2.52, 95% CI: 2.00-3.17), as well as worse CSS (pooled HR: 3.35, 95% CI: 1.90-5.91), PFS (pooled HR: 2.89, 95% CI: 1.67-5.01), and ORR (pooled odds ratio: 0.47, 95% CI: 0.27-0.82). Similarly, patients with PS ≥1 had significantly worse oncologic outcomes than those with PS = 0. CONCLUSIONS: In the NRCTs, poor PS was correlated with worse oncologic outcomes in aUC patients treated with ICIs. In the RCTs, ICIs performed better than chemotherapy across all PS categories. These findings should be interpreted with caution due to the high heterogeneity across the studies and patient populations. More RCTs including poor PS are needed to assess the impact of PS on ICI therapy outcomes. PATIENT SUMMARY: Immune therapy for patients with urothelial carcinoma should not be restricted on the grounds of performance status. However, patients with poor performance status should be considered for other factors such as life expectancy and comorbidities.

MoS2 nanosheets/silver nanoparticles anchored onto textile fabric as "dip catalyst" for synergistic p-nitrophenol hydrogenation.

Attaining a synergistic merge between the performance of homogenous catalysts and the recyclability of heterogeneous catalysts remains until now a concerning issue. The main challenge is to design efficient, low-cost catalyst with outstanding reusability, facile recovery, and ease of retrieval and monitoring between the reuses. Despite the vast efforts in the development of silver nanoparticle-based catalyst for the reaction of hydrogenation of 4-nitrophenol, the aforementioned criteria are infrequently found in a chosen system. Herein, we report a MoS2 nanosheet/silver nanoparticle-anchored PES-based textile as an efficient and recyclable "dip catalyst" for the 4-NP hydrogenation in the presence of sodium bohydride as model reaction. The textile fabric-based catalyst was processed via a simple sono-coating approach using MoS2 nanosheets as first coating layer followed by an in situ deposition of silver nanoparticles. The "dip catalyst" fabric is rapidly and easily removed from the reaction and then reinserted in the batch system to attain over 10 reaction cycles. Additionally, the produced textile materials were characterized via spectroscopic and microscopic tools such as FTIR, XRD, SEM, and EDX. Moreover, the sources of the high catalytic activity are also discussed and a plausible reaction mechanism is suggested. The present study demonstrates the potential of metal nanoparticle-textile material combination for future applications in chemical sustainable catalysis for environmental remediation purposes.

Engineering of amine-based binding chemistry on functionalized graphene oxide/alginate hybrids for simultaneous and efficient removal of trace heavy metals: Towards drinking water.

Engineering of versatile binding chemistry on graphene oxide surface using nucleophilic substitution/amidation reactions for highly efficient adsorption of Cd (II), Cu (II) and Pb (II) is herein proposed. Graphene oxide (GO) was used as a precursor for covalent bonding of hexamethylenediamine (HMDA) molecules via the nucleophilic substitution/amidation reactions on epoxy (COC) and carboxyl (COOH) groups to yield hexamethylenediamine functionalized graphene oxide (GO-HMDA) with multiple binding chemistries such as oxygen and nitrogen. Afterwards, GO-HMDA was encapsulated in alginate hydrogel beads with different loadings 5, 10, 15 and 20 wt% to produce Alg/GO-HMDA hybrid adsorbents for the removal of trace heavy metal ions from aqueous solution. Batch adsorption studies showed remarkable adsorption rates reaching 100% for Pb (II), 98.18% for Cu (II) and 95.19 for Cd (II) (~1 mg L-1) with only 15 wt% of GO-HMDA incorporated into the alginate beads. Moreover, Alg/GO-HMDA showed high removal efficiencies of heavy metals from tap water with a removal order of (Pb > Cu > Cd) similar to that observed in single aqueous solution. In Addition, the Alg/GO-HMDA adsorbents displayed excellent regeneration ability for six consecutive adsorption-desorption cycles confirming the high performance and potential of these adsorbents, for real heavy metals remediation in environment and in drinking waters in both single and multiple systems. Finally, the adsorption mechanism of traces heavy metals resulted from several phenomena including the electrostatic interactions occurring between the COOH groups of Alginate and the GO-HMDA surface groups as well as, through chelation interactions occurring between the metal cations and amino-functionalized groups of Alg/GO-HMDA 15 hybrid adsorbent.

Emerging Chemical Functionalization of g-C3N4: Covalent/Noncovalent Modifications and Applications.

Atomically 2D thin-layered structures, such as graphene nanosheets, graphitic carbon nitride nanosheets (g-C3N4), hexagonal boron nitride, and transition metal dichalcogenides are emerging as fascinating materials for a good array of domains owing to their rare physicochemical characteristics. In particular, graphitic carbon nitride has turned into a hot subject in the scientific community due to numerous qualities such as simple preparation, electrochemical properties, high adsorption capacity, good photochemical properties, thermal stability, and acid-alkali chemical resistance, etc. Basically, g-C3N4 is considered as a polymeric material consisting of N and C atoms forming a tri-s-triazine network connected by planar amino groups. In comparison with most C-based materials, g-C3N4 possesses electron-rich characteristics, basic moieties, and hydrogen-bonding groups owing to the presence of hydrogen and nitrogen atoms; therefore, it is taken into account as an interesting nominee to further complement carbon in applications of functional materials. Nevertheless, g-C3N4 has some intrinsic limitations and drawbacks mainly related to a relatively poor specific surface area, rapid charge recombination, a limited light absorption range, and a poor dispersibility in both aqueous and organic mediums. To overcome these shortcomings, numerous chemical modification approaches have been conducted with the aim of expanding the range of application of g-C3N4 and enhancing its properties. In the current review, the comprehensive survey is conducted on g-C3N4 chemical functionalization strategies including covalent and noncovalent approaches. Covalent approaches consist of establishing covalent linkage between the g-C3N4 structure and the chemical modifier such as oxidation/carboxylation, amidation, polymer grafting, etc., whereas the noncovalent approaches mainly consist of physical bonding and intermolecular interaction such as van der Waals interactions, electrostatic interactions, π-π interactions, and so on. Furthermore, the preparation, characterization, and diverse applications of functionalized g-C3N4 in various domains are described and recapped. We believe that this work will inspire scientists and readers to conduct research with the aim of exploring other functionalization strategies for this material in numerous applications.

New amino group functionalized porous carbon for strong chelation ability towards toxic heavy metals.

Herein, ethylenediamine functionalized porous carbon (PC-ED/1.5) was synthesized, then characterized by various methods and finally used as a functional material for Cu(ii) and Pb(ii) ion removal from water. XPS revealed the presence of numerous functionalities within the surface of PC including -NH and C-N-C groups. Furthermore, S BET, RS, XRD and FTIR analyses confirmed the changes implemented on the PC surface. Thereafter, a systematic study was implemented to analyze the interactions of the PC-ED/1.5 surface with Cu(ii) and Pb(ii) heavy metal ions. Hence, adsorption experiments showed that the PC-ED/1.5 exhibits maximum adsorption capacities of 123.45 mg g-1 and 140.84 mg g-1 for Cu(ii) and Pb(ii), respectively. Moreover, in situ electrostatic interactions occurring between the divalent cation and the PC-ED/1.5 functional groups was investigated. The mechanism involves chelation processes, electrostatic interactions and mechanical trapping of the metal ions in the adsorbent pores. Interestingly, a synergistic effect of the pores and surface active sites was observed. Finally, by using alginate bio-polymer we prepared membrane films of PC-ED/1.5 which showed long-term stability, regeneration capabilities and high mass recovery.