On the mechanism of carrier recombination in downsized blue micro-LEDs

The mechanism of carrier recombination in downsized μ-LED chips from 100 × 100 to 10 × 10 μm2 on emission performance was systemically investigated. All photolithography processes for defining the μ-LED pattern were achieved by using a laser direct writing technique. This maskless technology achieved the glass-mask-free process, which not only can improve the exposure accuracy but also save the development time. The multi-functional SiO2 film as a passivation layer successfully reduced the leakage current density of μ-LED chips compared with the μ-LED chips without passivation layer. As decreasing the chip size to 10 × 10 μm2, the smallest chip size exhibited the highest ideality factor, which indicated the main carrier recombination at the high-defect-density zone in μ-LED chip leading to the decreased emission performance. The blue-shift phenomenon in the electroluminescence spectrum with decreasing the μ-LED chip size was due to the carrier screening effect and the band filling effect. The 10 × 10 μm2 μ-LED chip exhibited high EQE values in the high current density region with a less efficiency droop, and the max-EQE value was 18.8%. The luminance of 96 × 48 μ-LED array with the chip size of 20 × 20 μm2 exhibited a high value of 516 nits at the voltage of 3 V.

TP53 Mutation Status and Biopsy Lesion Type Determine the Immunotherapeutic Stratification in Non-Small-Cell Lung Cancer

Immunotherapy, a chemotherapy-free process, has emerged as a promising therapeutic strategy to prolong the overall survival (OS) of patients with non-small-cell lung cancer (NSCLC). However, effective stratification factors for immunotherapy remain unclear. The purpose of this study was to discuss the potential stratification factors of NSCLC immunotherapy using immune checkpoint inhibitors (ICIs) by integrating genomic profiling and tumor lesion–type information. In this study, 344 patients with NSCLC, whose clinical and tissue (including metastatic and primary lesions) mutation information was available, were included. The potential gene mutation status for predicting the outcomes of immunotherapy was screened by comparing the difference in mutation frequency between responders and non-responders. Our results indicated that the potential predictors of immunotherapy were significantly different, especially between patients with TP53(+) (including metastatic and primary lesions) and TP53(−) (including metastatic and primary lesions). According to this classification, patients with NSCLC who suggested immunotherapy had a higher OS than those who did not (25 months vs. 7 months, P < 0.0001, hazard ratio = 0.39). Collectively, this study provides a new perspective for screening immunotherapy predictors in NSCLC, suggesting that the TP53 mutation status and source of biopsy tissue should be considered during the development of immunotherapy biomarkers.

HOT MELT EXTRUSION IN ENGINEERING OF DRUG COCRYSTALS: A REVIEW

Crystal engineering technique has been widely explored in recent times to bring about changes in crystallinity which aids to achieve various goals such as solubility enhancement, stability and in vivo bioavailability without altering the chemical properties of the drug. Cocrystallisation is one of the crystal engineering approaches where the drug and an inert coformer are linked together by hydrogen bonding forming supramolecular homosynthon or heterosynthon using solvent-based or solvent-free techniques. Processing of active pharmaceutical ingredients with inert water-soluble coformers yields multicomponent crystalline cocrystals with high-performance characteristics and enhanced flow properties. Due to the emerging need of the industry for greener techniques, hot melt extrusion (HME), a continuous and solvent-free process is emerging as a field of interest in the mechanochemical synthesis of various pharmaceutical dosage forms such as solid dispersions, implants, ointments, and cocrystals. The current review emphasizes the role of HME as a cocrystallization technique for drugs to tailor-make their properties and ease of formulation. The distinct feature of HME is phase control during the process of cocrystallization. Furthermore, the selection of appropriate coformers with desirable water-solubility and stability features makes HME amenable to cocrystallization of versatile actives yielding suitable dosage forms. The application of process analytical technology further adds ease of monitoring during HME in cocrystallization approaches. Due to these salient features of HME, it can act as a prospective technique for cocrystallization of versatile drugs thus yielding dosage forms with desirable solubility and stability features.

Random Cyclic Triangle-Free Graphs of Prime Order

Cyclic triangle-free process (CTFP) is the cyclic analog of the triangle-free process. It begins with an empty graph of order n and generates a cyclic graph of order n by iteratively adding parameters, chosen uniformly at random, subject to the constraint that no triangle is formed in the cyclic graph obtained, until no more parameters can be added. The structure of a cyclic triangle-free graph of the prime order is different from that of composite integer order. Cyclic graphs of prime order have better properties than those of composite number order, which enables generating cyclic triangle-free graphs more efficiently. In this paper, a novel approach to generating cyclic triangle-free graphs of prime order is proposed. Based on the cyclic graphs of prime order, obtained by the CTFP and its variant, many new lower bounds on R 3 , t are computed, including R 3,34 ≥ 230 , R 3,35 ≥ 242 , R 3,36 ≥ 252 , R 3,37 ≥ 264 , R 3,38 ≥ 272 . Our experimental results demonstrate that all those related best known lower bounds, except the bound on R 3,34 , are improved by 5 or more.

Confronting repressive ideologies with critical pedagogy in science classrooms

The focus of this response to Arthur Galamba and Brian Matthews’s ‘Science education against the rise of fascist and authoritarian movements: towards the development of a Pedagogy for Democracy’ is to underpin a critical pedagogy that can be used as a counterbalancing force against repressive ideologies within science classrooms. Locating science education within the traditions of critical pedagogy allows us to interrogate some of the historical, theoretical, and practical contradictions that have challenged the field, and to consider science learning as part of a wider struggle for social justice in education. My analysis draws specifically on the intellectual ideas of Paulo Freire, whose work continues to influence issues of theoretical, political, and pedagogical importance. A leading social thinker in educational practice, Freire rejected the dominant hegemonic view that classroom discourse is a neutral and value-free process removed from the juncture of cultural, historical, social, and political contexts. Freire’s ideas offer several themes of relevance to this discussion, including his banking conception of education, dialog and conscientization, and teaching as a political activity. I attempt to show how these themes can be used to advance a more socially critical and democratic approach to science teaching.

Improved Mechanical, Thermal, and Hydrophobic Properties of PLA Modified with Alkoxysilanes by Reactive Extrusion Process

An eco-friendly strategy for the modification of polylactic acid (PLA) surface properties, using a solvent-free process, is reported. Reactive extrusion (REX) allowed the formation of new covalent bonds between functional molecules and the PLA polymeric matrix, enhancing its mechanical properties and modifying surface hydrophobicity. To this end, the PLA backbone was modified using two alkoxysilanes, phenyltriethoxysilane and N-octyltriethoxysilane. The reactive extrusion process was carried out under mild conditions, using melting temperatures between 150 and 180 °C, 300 rpm as screw speed, and a feeding rate of 3 kg·h−1. To complete the study, flat tapes of neat and functionalized PLA were obtained through monofilament melt extrusion to quantify the enhancement of mechanical properties and hydrophobicity. The results verified that PLA modified with 3 wt% of N-octyltriethoxysilane improves mechanical and thermal properties, reaching Young’s modulus values of 4.8 GPa, and PLA hydrophobic behavior, with values of water contact angle shifting from 68.6° to 82.2°.

Organic Solvent Free Process to Fabricate High Performance Silicon/Graphite Composite Anode

Cycling stability is a key challenge for application of silicon (Si)-based composite anodes as the severe volume fluctuation of Si readily leads to fast capacity fading. The binder is a crucial component of the composite electrodes. Although only occupying a small amount of the total composite mass, the binder has major impact on the long-term electrochemical performance of Si-based anodes. In recent years, water-based binders including styrene-butadiene rubber (SBR) and carboxymethyl cellulose (CMC) have attracted wide research interest as eco-friendly and low-cost alternatives for the conventional poly(vinylidene difluoride) (PVDF) binder in Si anodes. In this study, Si-based composite anodes are fabricated by simple solid mixing of the active materials with subsequent addition of SBR and CMC binders. This approach bypasses the use of toxic and expansive organic solvents. The factors of binder, silicon, and graphite materials have been systematically investigated. It is found that the retained capacities of the anodes are more than 440 mAh/g after 400 cycles. These results indicate that organic solvent free process is a facile strategy for producing high performance silicon/graphite composite anodes.