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Aromaticity is a fundamental concept in organic chemistry. Hyperconjugative aromaticity, also known as hyperconjugation-induced aromaticity, has evolved from its origin from main group substituents to transition metal analogues, establishing itself as an important category of aromaticity. Additionally, aromatic compounds comprising two sp3-carbon atoms have recently been reported both experimentally and computationally. However, what is the maximum number of sp3-hybridized atoms needed to maintain hyperconjugative aromaticity? Here, we report that hyperconjugative aromaticity can be achieved in hexa-substituted indoliums and octa-substituted pyrroliums, possessing three-five sp3-hybridized carbon/nitrogen atoms by means of density functional theory (DFT) calculations. The aromaticity was confirmed by using various aromaticity indices, i.e., NICS, MCI, and EDDB. Notably, the strong electron-donating ability and aurophilicity of Au(I) substituents play a pivotal role in maintaining the aromaticity and structural integrity. In addition, increasing the number of hyperconjugative centers will decrease the aromaticity in these five-membered rings. Our findings highlight the significance of transition metal substituents in hyperconjugative aromaticity and offer a novel approach for designing aromatic organometallics.

Since toys are potential sources of lead contamination for young children, we aim to explore potential correlations between blood-lead-levels (BLLs) of young children and toy-lead contamination using two concurrent investigations. In investigation-1, a total of 2249 children under 7 years old were studied using stratified-cluster-sampling in 6 districts of Shanghai, parents completed questionnaires and children’s whole-blood was collected, and then BLLs were measured using tungsten-atomizer-absorption-spectrophotometer. In investigation-2, a total of 288 toys made of different materials (plastic, wooden, metals, and stuffed cloth) were collected in 6 great supermarkets/toy-stores and toy-lead-levels were measured by a portable X-ray-fluorescence instrument. The geometric-mean of BLLs was 2.02 μg/dL. Adjusting for related confounders, playing with plastic toys was a significant risk factor (β= 0.067, P< 0.05) for BLL-increment. Plastic toys accounted for the highest proportion (154/288, 53.47%) and had the highest rates exceeding toy-lead-standards (the over-standard rates of ≥ 300/600 mg/kg, plastic toys: 3.90%/1.30%; other toys: 0.00%/0.00%). Children’s BLLs in the three (Pudong-suburban, Xuhui, and Yangpu) districts and toy-lead over-standard rates in the neighboring stores were compared, the highest BLLs and over-standard rates were both found in Pudong-suburban district and similar BLLs and over-standard rates were observed between Yangpu and Xuhui districts (Pudong-suburban vs. Xuhui vs. Yangpu: 2.07 vs. 1.55 vs. 1.50 μg/dL for the medians of BLLs, P< 0.001; 1.67% vs. 0.00% vs. 0.00% for the over-standard rates of ≥ 600 mg/kg). This study raised the possibility that lead contamination in toys (especially in low social-economic-status areas) might be associated with BLLs in young children. Lead contamination from plastic toys needs cautions for preventing children from lead exposure.

Compared to the impressive advances achieved in coil–coil block copolymers (BCPs) capable of crystallization, advances in conjugated rod–rod BCPs are somewhat limited owing to their semirigid characteristics. The ability to tune crystallization and microphase segregation in this class of BCPs enables efficient control of the microstructures and the physical and optoelectronic properties. Herein, we report the effective manipulation of the cocrystallization and microphase segregation in a series of conjugated triblock copolymers through meticulous control of the length of the middle amorphous block at the molecular level and scrutinize the close correlation between their crystalline structures and charge transport properties. Specifically, a family of poly(3-hexylthiophene)-block-poly[3-(6-bromohexyl)-thiophene]-block-poly(3-decylthiophene) (P3HT-b-P3BrHT-b-P3DT) BCPs was designed and synthesized, in which the central P3BrHT had a low rigidity and negligible crystalline property compared with the two outer P3HT and P3DT blocks. The shorter P3BrHT was favorable to the cocrystallization of the two outer P3HT and P3DT. Moreover, the phase transition from the cocrystallization of P3HT and P3DT to their microphase segregation was facilitated by increasing the length of the central P3BrHT (intrinsic factor) in conjunction with slow solvent evaporation and thermal treatment (extrinsic factors). Finally, the different crystalline structures of P3HT-b-P3BrHT-b-P3DT are strongly correlated with their optical and charge transport properties. This study provides insights into cocrystallization and microphase segregation in conjugated BCPs via meticulous molecular design at the molecular level and external processing strategies.

Installing an electric-controlled pressure relief valve with battery fault detection capability on a liquid-cooled battery pack can prevent explosions caused by thermal runaway.

The auto-transformer rectifier unit (ATRU) is one of the most widely used avionic secondary power supplies. Timely fault identification and location of the ATRU is significant in terms of system reliability. A two-level fault diagnosis method for the ATRU using multi-source features (MSF) is proposed in this paper. Based on the topology of the ATRU, three key electrical signals are selected and analyzed to extract appropriate features for fault diagnosis. Mathematic expressions and simulation results of the feature signals under different fault modes are presented in the paper. Therefore, a unique MSF system is developed and a two-level fault diagnosis method based on radial basis function network groups is proposed. On the first level, the overall fault set is classified into three subsets and then on the second level, three radial basis function neural networks are constructed and trained to realize accurate fault localization. To verify the diagnosis performance of the proposed method, several comparative tests are implemented on a 12-pulse ATRU system, which shows that this method has a lower computational cost, better diagnostic accuracy and increased stability when compared with alternative methods.

Aromaticity, in general, can promote a given reaction by stabilizing a transition state or a product via a mobility of π electrons in a cyclic structure. Similarly, such a promotion could be also achieved by destabilizing an antiaromatic reactant. However, both aromaticity and transition states cannot be directly measured in experiment. Thus, computational chemistry has been becoming a key tool to understand the aromaticity-driven reaction mechanisms. In this review, we will analyze the relationship between aromaticity and reaction mechanism to highlight the importance of density functional theory calculations and present it according to an approach via either aromatizing a transition state/product or destabilizing a reactant by antiaromaticity. Specifically, we will start with a particularly challenging example of dinitrogen activation followed by other small-molecule activation, CF bond activation, rearrangement, as well as metathesis reactions. In addition, antiaromaticity-promoted dihydrogen activation, CO2capture, and oxygen reduction reactions will be also briefly discussed. Finally, caution must be cast as the magnitude of the aromaticity in the transition states is not particularly high in most cases. Thus, a proof of an adequate electron delocalization rather than a complete ring current is recommended to support the relatively weak aromaticity in these transition states.

The ability to control the polymorph in conjugated polymers offers a robust means of scrutinizing the structure–property correlation as various polymorphs with a slight difference in crystal packing greatly impact their solid-state properties. Notably, despite a few studies on the polymorphs of conjugated homopolymers, polymorph control in conjugated polymer blends has yet to be explored. Herein, we report, for the first time, the tailoring of polymorphs (i.e., polymorphs I and II) in a set of poly(3-butylthiophene)/poly(3-hexylselenophene) (P3BT/P3HS) blends with various molecular weights (MWs) via a simple yet efficient meniscus-assisted solution-shearing (MASS) approach. The MASS process renders appealing polymorph transformation of the respective conjugated polymer as well as cocrystallization of either P3BT and P3HS or their phase separation, resulting in different optical properties for each blend. Specifically, P3BT-3K/P3HS-3K, P3BT-3K/P3HS-16K, and P3BT-16K/P3HS-16K blends display a phase-separated structure containing the respective P3BT and P3HS crystals in the drop-cast film, where P3BT-3K and P3BT-16K have polymorphs II and I, respectively, and P3HS-3K and P3HS-16K possess polymorphs II and I, respectively, with minor polymorph II in P3HS-16K as well. This contrasts with the cocrystallization formed in the drop-cast P3BT-16K/P3HS-3K film. Intriguingly, when subjecting the P3BT/P3HS blend solutions to the MASS, the polymorph of P3BT-3K in both P3BT-3K/P3HS-3K and P3BT-3K/P3HS-16K blends transform from polymorph II to I, and cocrystallizes with P3HS-3K in the P3BT-3K/P3HS-3K yet phase-separates with P3HS-16K in the P3BT-3K/P3HS-16K. Increasing MW in the P3BT-16K/P3HS-16K blend confers it to cocrystallize more readily than the low-MW P3BT-3K/P3HS-3K blend due to the more matchable crystal size in the former blend. The polymorph transformation kinetics and associated morphology evolution are scrutinized. These P3BT/P3HS blends with different crystalline structures are found to correlate closely to their optical properties. This work elucidates how P3BT and P3HS experience the polymorph transformation and interact with each other to cocrystallize or phase-separate imparted by a facile MASS process, thereby strengthening the fundamental understanding of polymorph transformation and crystallization behavior in conjugated polymer blends.

Aromaticity and hyperconjugation are two fundamental concepts in chemistry. Combining them together led to the proposal of the concept of hyperconjugative aromaticity by Mulliken in 1939. Now, it has been attracting considerable attention from both theoretical and experimental chemists. Recently, the concept of hyperconjugative aromaticity has been extended from main-group substituents to transition metal systems including groups 9, 10, and 11 transition metal substituents. Here, we report the hyperconjugative aromaticity in cyclopentadienes and pyrroliums containing group 7 transition metal substituents through density functional theory (DFT) calculations. It is found that the metal–metal bonding interaction can significantly reduce the aromaticity in cyclopentadienes, whereas the stronger σ-donor ligand, bridged hydride, and carbonyls can enhance aromaticity. All these findings expand the scope of the concept of hyperconjugative aromaticity, enriching aromatic organometallic chemistry.

Despite impressive progress in the research of all-conjugated diblock copolymers, there is a quite limited investigation into triblock counterparts. Moreover, regarding the block sequence, which is peculiar to triblock copolymers, its effect on their crystallization and microphase separation is still poorly understood. Herein, we design and synthesize a family of all-conjugated triblock copolymers comprising poly(3-butylthiophene) (P3BT), poly(3-hexylselenophene) (P3HS), and poly(3-dodecylthiophene) (P3DDT) of various block sequences, i.e., P3BT-b-P3DDT-b-P3HS, P3BT-b-P3HS-b-P3DDT, and P3HS-b-P3BT-b-P3DDT, elucidate the impact of the block sequence on their crystalline structures in conjunction by utilizing various solvents and thermal annealing, and investigate the charge transport properties of these different crystalline structures. Remarkably, the block sequence with the P3DDT block located in the central position (P3BT-b-P3DDT-b-P3HS) and faster solvent evaporation favor the cocrystals, while the P3DDT block situated at terminals (P3BT-b-P3HS-b-P3DDT and P3HS-b-P3BT-b-P3DDT), slower evaporation of the solvent, and heating lead to microphase separation over cocrystallization. Intriguingly, three different microphase-separated structures, which are correlated to the block sequence, are observed after high-temperature annealing (240 °C). Moreover, these various crystalline structures of triblock copolymers influence their charge mobilities in organic field-effect transistors (OFETs) closely. Thus, this work comprehensively elucidates the effect of the block sequence (intrinsic factor), solvent, and heating temperature (extrinsic factors) on the crystalline structure and electrical properties of conjugated triblock copolymers.

Conjugated rod–rod block copolymers (BCPs) are important semiconducting materials because they combine the unique microphase-separation characteristics of BCPs with the remarkable optoelectronic properties of conjugated polymers. The ability to tailor the two fundamental phase transitions (microphase separation and crystallization) in BCPs could enable efficient control over their physical and optoelectronic properties. Herein, a set of poly(3-butylthiophene)-block-poly(3-dodecylthiophene) (P3BT-b-P3DDT) BCPs with controlled block ratios are synthesized and the interplay between their microphase separation and cocrystallization is explored by tuning both the intrinsic (i.e., block ratios) and extrinsic factors (i.e., solvent and thermal annealing temperatures). An increased P3BT content, slower solvent evaporation, and higher thermal annealing temperatures favor microphase separation in P3BT-b-P3DDT. Furthermore, the relationship between various P3BT-b-P3DDT crystalline structures and their charge-transport properties is scrutinized. This work elucidates how P3BT-b-P3DDT BCPs undergo microphase separation and crystallization and how these processes can be tailored, strengthening our fundamental understanding of conjugated rod–rod BCP systems.

The ability to tune the polymorph and crystal orientation of semiconducting conjugated polymers provides a powerful platform for revealing processing–structure–property relationships. In contrast to the widely studied poly(3-alkylthiophene)s, their close poly(3-alkylselenophene) analogs have been much less studied. Herein, we report tailoring the polymorphs and crystal orientations in poly(3-hexylselenophene) (P3HS) of different molecular weights (MWs) via rubbing and elucidate the relationships between the crystalline structure and charge transfer characteristics for organic field-effect transistors (OFETs). In particular, the as-cast P3HS-3K film exhibits polymorph II with a dominant flat-on crystal orientation; however, it transforms into polymorph I with a face-on crystal orientation upon rubbing at elevated temperatures. Moreover, the as-cast P3HS-22K film transitions from edge-on to face-on with its polymorph I retained throughout the rubbing process. The polymorph and crystal orientation transitions in the P3HS-3K and 22K systems are accompanied by the formation of large-scale highly aligned crystalline films along the rubbing direction. The polymorph transformation kinetics during the rubbing process and associated alterations in the crystalline packing and photophysical properties are investigated. The various P3HS films exhibit OFET performance that shows a strong relationship with the attained crystalline structures. Such polymorph and crystal orientation transformations involving the rubbing technique are readily applied to other conjugated polymers in interest. This research emphasizes tailoring the crystalline structures and, thus, the charge transfer characteristics of conjugated polymers, which advances their use in optoelectronic-device applications.

Recently, wearable and breathable healthcare devices for air filtering and real-time vital signs monitoring have become urgently needed since virus and particulate matter (PM) cause serious health issues. Herein, we present a trap-induced dense monocharged hybrid perfluorinated electret nanofibrous membrane (HPFM) for highly efficient ultrafine PM0.3removal with an efficiency of 99.712% under low pressure drop (38.1 Pa) and high quality factor of 0.154 Pa–1. Furthermore, a recyclable multifunctional healthcare mask is constructed by integrating the HPFM-based nanogenerator, which realizes efficient PM0.3filtering and wireless real-time human respiration monitoring simultaneously. More importantly, the performance of this mask is still relatively stable even at 100%RH humidity and 92 °C temperature conditions for 48 h, which infers that it can be reused after disinfection. The strategy of fabricating HPFM provides an approach to obtain charge-rich stable electret materials, and the design of multifunctional masks demonstrates their potential application for future personal protection and health monitoring devices.

ABSTRACTThe precise mechanism through which macroautophagy/autophagy affects psoriasis is poorly understood. Here, we found that keratinocyte (KC) autophagy, which was positively correlated with psoriatic severity in patients and mouse models and could be inhibited by mitogen-activated protein kinase (MAPK) family inactivation. The impairment of autophagic flux alleviated psoriasisform inflammation. We also found that an autophagy-based unconventional secretory pathway (autosecretion) dependent on ATG5 (autophagy related 5) and GORASP2 (golgi reassembly stacking protein 2) promoted psoriasiform KC inflammation. Moreover, the alarmin HMGB1 (high mobility group box 1) was more effective than other autosecretory proteins in regulating psoriasiform cutaneous inflammation. HMGB1 neutralization in autophagy-efficient KCs eliminated the differences in psoriasiform inflammation between Krt14+/+-Atg5f/fKCs and Krt14Cre/+-atg5f/fKCs, and conversely, recombinant HMGB1 almost completely restored psoriasiform inflammation in Krt14Cre/+-atg5f/fKCs in vivo. These results suggest that HMGB1-associated autosecretion plays a pivotal role in cutaneous inflammation. Finally, we demonstrated that Krt14Cre/+-hmgb1f/fmice displayed attenuated psoriatic inflammation due to the essential crosstalk between KC-specific HMGB1-associated autosecretion and γδT cells. Thus, this study uncovered a novel autophagy mechanism in psoriasis pathogenesis, and the findings imply the clinical significance of investigating and treating psoriasis.Abbreviations:3-MA: 3-methyladenine; ACTB: actin beta; AGER: advanced glycosylation end-product specific receptor; Anti-HMGB1: anti-HMGB1 neutralizing antibody; Anti-IL18: anti-IL18 neutralizing antibody; Anti-IL1B: anti-IL1B neutralizing antibody; ATG5: autophagy related 5; BAF: bafilomycin A1; BECN1: beclin 1; CASP1: caspase 1; CCL: C-C motif chemokine ligand; CsA: cyclosporine A; ctrl shRNA: lentivirus harboring shRNA against control; CXCL: C-X-C motif chemokine ligand; DCs: dendritic cells; DMEM: dulbecco’s modified Eagle’s medium; ELISA: enzyme-linked immunosorbent assay; EM: electron microscopy; FBS: fetal bovine serum; GORASP2shRNA: lentivirus harboring shRNA against GORASP2; GORASP2/GRASP55: golgi reassembly stacking protein 2; GR1: a composite epitope between LY6 (lymphocyte antigen 6 complex) locus C1 and LY6 locus G6D antigens; H&E: hematoxylin and eosin; HMGB1: high mobility group box 1; HMGB1shRNA: lentivirus harboring shRNA against HMGB1; IFNG/IFN-γ: interferon gamma; IL17A: interleukin 17A; IL18: interleukin 18; IL1A/IL-1α: interleukin 1 alpha; IL1B/IL-1β: interleukin 1 beta; IL22/IL-22: interleukin 22; IL23A: interleukin 23 subunit alpha; IL23R: interleukin 23 receptor; IMQ: imiquimod; ITGAM/CD11B: integrin subunit alpha M; ITGAX/CD11C: integrin subunit alpha X; IVL: involucrin; KC: keratinocyte; KD: knockdown; KO: knockout; Krt14+/+-Atg5f/fmice: mice bearing an Atg5 floxallele, in which exon 3 of the Atg5gene is flanked by two loxP sites; Krt14+/+-Hmgb1f/f: mice bearing an Hmgb1flox allele, in which exon 2 to 4 of the Hmgb1gene is flanked by two loxP sites; Krt14Cre/+-atg5f/fmice: keratinocyte-specific atg5knockout mice generated by mating Atg5-floxedmice with mice expressing Crerecombinase under the control of the promoter of Krt4; Krt14Cre/+-hmgb1f/fmice: keratinocyte-specific hmgb1knockout mice generated by mating Hmgb1-floxedmice with mice expressing Crerecombinase under the control of the promoter of Krt14; Krt14-Vegfamice: mice expressing 164-amino acid Vegfasplice variant recombinase under the control of promoter of Krt14; LAMP1: lysosomal associated membrane protein 1; LDH: lactate dehydrogenase; LORICRIN: loricrin cornified envelope precursor protein; M5: TNF, IL1A, IL17A, IL22 and OSM in combination; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MAPK: mitogen-activated protein kinase; MKI67: marker of proliferation Ki-67; MTT: thiazolyl blue tetrazolium bromide; NFKB/NF-κB: nuclear factor kappa B; NHEKs: primary normal human epidermal keratinocytes; NS: not significant; OSM: oncostatin M; PASI: psoriasis area and severity index; PtdIns3K: class III phosphatidylinositol 3-kinase; qRT-PCR: quantitative RT-PCR; RELA/p65: RELA proto-oncogene, NF-kB subunit; rHMGB1: recombinant HMGB1; rIL18: recombinant interleukin 18; rIL1B: recombinant interleukin 1 beta; S100A: S100 calcium binding protein A; SQSTM1/p62: sequestosome 1; T17: IL17A-producing T; TCR: T-cell receptor; tcrdKO mice: tcrd(T cell receptor delta chain) knockout mice, which show deficient receptor expression in all adult lymphoid and epithelial organs; TLR: toll-like receptor; TNF/TNF-α: tumor necrosis factor; WOR: wortmannin; WT: wild-type; γδT17 cells: IL17A-producing γδ T cells.

The cocrystallization method that combines various constituents into cocrystals yields the newly formed materials with significantly enhanced charge transport properties. However, this strategy has not been greatly utilized in all-conjugated block copolymers (BCPs). Herein, we scrutinize the relationship between cocrystals and charge mobilities in all-conjugated BCPs (i.e., poly(3-butylthiophene)-block-poly(3-hexylthiophene); denoted P3BT-b-P3HT) by tuning their molecular weights and thermal annealing process. All the rod–rod BCPs form cocrystals with high charge mobilities than P3BT and P3HT homopolymers and P3BT/P3HT blend, imparting the cocrystal-facilitated charge transport because of the synergy of two conjugated components. Upon 150 °C treatment, their crystallinities increase and their charge mobilities at 15k, 18k, and 28k increase slightly. In contrast, P3BT-b-P3HT-12k shows decreased charge mobilities. It is due to the preferential increase of crystal size and order through the π–π stacking direction in the former while through the alkyl stacking direction in the latter. Intriguingly, when these P3BT-b-P3HT cocrystals experience two-step thermal treatment, P3BT-b-P3HT-12k retains its cocrystalline structure, while microphase separation of P3BT and P3HT occurs in P3BT-b-P3HT-15k, 18k, and 28k with different degrees. All P3BT-b-P3HT BCPs exhibit decreased charge mobilities. This study demonstrates the cocrystallization-promoted charge mobility in all-conjugated BCPs, which may facilitate their application in a wide range of optoelectronic devices.

Despite significant advances in double-crystalline coil–coil block copolymers (BCPs), investigations into double-crystalline all-conjugated rod–rod BCPs have been comparatively fewer and are limited in scope. Moreover, the ability to control the crystalline structures of all-conjugated BCPs may endow the materials and devices with enhanced optoelectronic properties over the two respective constituents. Herein, we report the synthesis of a series of poly(3-hexylthiophene)-block-poly(3-butylselenophene) (P3HT-b-P3BS) BCPs with tunable block ratios and investigate the effects of block ratio and thermal annealing process on their crystallization and microphase-separated structures. These rod–rod BCPs exhibit a sole P3HT crystallization (P3HT/P3BS = 63:37) or individual P3HT and P3BS crystallization (P3HT/P3BS = 55:45 and 42:58) in as-cast thin films, influenced by the block ratio of P3HT/P3BS. Interestingly, upon 200 °C-annealing (i.e., annealed at the temperature below the melting points of P3HT and P3BS form I blocks), P3HT-b-P3BS (P3HT/P3BS = 63:37) remains the sole P3HT crystallization, while P3HT-b-P3BS (P3HT/P3BS = 55:45 and 42:58) transforms from two individual P3HT and P3BS crystal domains into cocrystals, accompanied by the phase transition of P3BS block from form II to I. Remarkably, after a higher thermal annealing at 230 °C (i.e., close to the melting point of P3HT block yet below the melting point of P3BS form I block), the cocrystalline structures originally existing in P3HT-b-P3BS (P3HT/P3BS = 55:45 and 42:58) at the 200 °C-annealing process do not form, and they reverse back to individual P3HT and P3BS form I crystals. Finally, the relationship between various structures of P3HT-b-P3BS and the resulting charge mobilities is clarified. This study provides an insight into the interplay between microphase separation of P3HT-b-P3BS and crystallization of both P3HT and P3BS blocks tailored by the block ratio and thermal annealing temperature and correlates their different structures with the charge transport properties.

•Formulation Al@AP/PVDF is optimized on the basis of the maximum energy release.•The thermal decomposition process and reaction mechanisms of Al@AP/PVDF with GO doped are be clarified.•Better morphology and doping of GO could improve the combustion property, density, and the heat of reaction, etc.

Despite recent impressive advances in synthesis of all-conjugated diblock copolymers via facile quasi-living Grignard metathesis (GRIM) polymerization, it remains challenging to achieve well-defined all-conjugated triblock copolymers of interest. Herein, we report the judicious design and synthesis of a series of all-conjugated triblock copoly(3-alkylthiophene)s consisting of poly(3-butylthiophene) (P3BT), poly(3-hexylthiophene) (P3HT), poly(3-octylthiophene) (P3OT), or poly(3-dodecylthiophene) (P3DDT) in all 12 possible combinations. The effects of block sequences and the length of alkyl side chains on their cocrystallization and microphase-separated structures are investigated. Moreover, the correlation between different crystalline structures and charge mobilities in organic field-effect transistors (OFETs) is scrutinized. These rationally synthesized triblock copoly(3-alkylthiophene)s self-assemble into cocrystals with an edge-on orientation in as-cast and 150 °C-annealed samples. Remarkably, the combinations with the shortest alkyl side chains placed as the central block (i.e., P3HT-b-P3BT-b-P3OT, P3HT-b-P3BT-b-P3DDT, P3OT-b-P3BT-b-P3DDT, and P3OT-b-P3HT-b-P3DDT) exhibit higher film crystallinity and charge mobilities than the other two combinations where the blocks with shortest alkyl side chains are located at two terminals. Intriguingly, upon thermal annealing near the melting temperature of these combinations, P3BT-b-P3OT-b-P3HT, P3BT-b-P3DDT-b-P3OT, and P3HT-b-P3DDT-b-P3OT can retain their cocrystalline structure while the other combinations are found to microphase separate. Finally, the all-conjugated triblock copoly(3-alkylthiophene)s with proper block sequence demonstrate stable charge mobilities at high temperatures and good flexibility in OFET devices. Taken together, this study elucidates that the block sequence is of key importance on control of the crystallization and charge transport behavior of poly(3-alkylthiophene)-based triblock copolymers.

Density functional theory calculations were used to investigate the reaction mechanisms on [3 + 2] cycloaddition reactions of azides with metal carbyne complexes. Our results reveal that the formation of a 1,4-metallatriazole regioisomer is a kinetically favorable process in comparison with the formation of 1,5-metallatriazole. Aromaticity plays an important role in stabilizing the products in these reactions. Further analyses show that the electron-donating ligand on metal centers or the electron-withdrawing group on the azide could accelerate the [3 + 2] cycloaddition reaction. All of these findings could be useful for experimental chemists to develop “click reactions” in organometallic chemistry.

In this paper, the composites of a newly insensitive high explosive 2,4,6-triamino-5-nitropyrimidine-1,3-dioxide (ICM-102) with nanosized metals (Al, Co, Mg, Si, Ti, and Zr) and nanosized metal oxides (CuO and Fe2O3) have been prepared and investigated in terms of thermal reactivity. The catalytic effects on the thermal decomposition of ICM-102 composites have been investigated by TGA-DSC technique. Among all the composites, ICM-102/Co shows the minimum residue rate of 1.57 wt % and ICM-102/Si shows the maximum heat release of 1001.9 J g–1. The kinetic parameters for the catalytic decomposition of ICM-102 have been obtained. The activation energy (Ea) of ICM-102 decomposition is within 197.9–212.0 kJ mol–1. Compared with ICM-102, the Eaof ICM-102/Si decomposition was decreased by about 90 kJ mol–1. The decomposition gaseous products of ICM-102 and its composites have been analyzed by the TG-MS technique. It has been shown that the main gaseous products are H2O, C2H4, C3, and C2N or C3H2. The ICM-102 decomposition undergoes intramolecular dehydration, followed by two different ring-opening chemical pathways. The decomposition products are largely dependent on the type of additives.

Background: Accumulating observational studies have identified associations between type 1 diabetes (T1D) and polycystic ovary syndrome (PCOS). Still, the evidence about the causal effect of this association is uncertain. Methods: We performed a two-sample Mendelian randomization (MR) analysis to test for the causal association between T1D and PCOS using data from a large-scale biopsy-confirmed genome-wide association study (GWAS) in European ancestries. We innovatively divided T1D into nine subgroups to be analyzed separately, including: type1 diabetes wide definition, type1 diabetes early onset, type 1 diabetes with coma, type 1 diabetes with ketoacidosis, type 1 diabetes with neurological complications, type 1 diabetes with ophthalmic complications, type 1 diabetes with peripheral circulatory complications, type 1 diabetes with renal complications, and type 1 diabetes with other specified/multiple/unspecified complications. GWAS data for PCOS were obtained from a large-scale GWAS (10,074 cases and 103,164 controls) for primary analysis and the IEU consortium for replication and meta-analysis. Sensitivity analyses were conducted to evaluate heterogeneity and pleiotropy. Results: Following rigorous instrument selection steps, the number of SNPs finally used for T1D nine subgroups varying from 6 to 36 was retained in MR estimation. However, we did not observe evidence of causal association between type 1 diabetes nine subgroups and PCOS using the IVW analysis, MR-Egger regression, and weighted median approaches, and all Pvalues were > 0.05 with ORs near 1. Subsequent replicates and meta-analyses also yielded consistent results. A number of sensitivity analyses also did not reveal heterogeneity and pleiotropy, including Cochran’s Qtest, MR-Egger intercept test, MR-PRESSO global test, leave-one-out analysis, and funnel plot analysis. Conclusion: This is the first MR study to investigate the causal relationship between type 1 diabetes and PCOS. Our findings failed to find substantial causal effect of type 1 diabetes on risk of PCOS. Further randomized controlled studies and MR studies are necessary.

In order to enhance the heat release of nanoparticles silicon, the Si@AP/NC metastable intermixed composites (MICs) Si@AP/NC with varied content of silicon (40%, 60%, and 80%) were designed and prepared by electrospray. Observation by scanning electron microscopy (SEM) has shown that the morphological characterization of those composites was homogeneously mixed. The thermal properties of those MICs were evaluated by means of DSC-TG techniques. Results show that the low- and high-temperature decomposition of AP transitioned from two separated stages to a one-step process. This was mainly caused by the interaction of thin silica on the surface of silicon and perchloric acid. The dependence of activation energy on the conversation rate was obtained by making use of state-of-the-art kinetic procedures. It has been found that decomposition of Si@NC/AP-40 and Si@NC/AP-60 followed the random chain scission model. With the strengthening of active centers of silica, the mechanism of proton migration of AP turned into the growth of the nucleus. The decomposition process of AP started on the surface of the crystal and gradually decomposed steadily as AP decomposition proceeded. Therefore, it is a first-order reaction model for Si@NC/AP-60 and Si@NC/AP-80 in their second-step reaction. Overall, manufacture spherical Si-NPs composites wrapped in polymer though electrostatic spray technology, a novel way of preparing nanoenergetic materials was created. These nanocomposites could be applied normally as fuels in thermobaric explosives or solid propellants. Graphical abstract.

By virtue of simple fabrication, low cost, and high conversion efficiency, nanogenerators play a key role in promoting the development of self-powered systems and large-scale mechanical energy harvesting. Efforts have been ongoing for improving the output power of nanogenerators by maximizing their surface charge density via surface modification or structure optimization. Nevertheless, because of inevitable air breakdown during the operation process, enhancing charge density is not retainable, which is the most crucial limitation for the output performance of nanogenerators. Here, a suppressing breakdown strategy is developed to remarkably enhance the output charge density of the nanogenerator by embedding a dielectric film (polyvinylidene fluoride) with high permittivity into air gaps. Because of the air breakdown suppression and strongly field-induced dielectric polarization effect, the output charge density of ∼470 μC m–2is obtained at ambient condition, which is ∼4 times larger than the value of the conventional nanogenerator with air breakdown. In addition, the effects of different dielectric materials and their different thicknesses are also studied for enhancing the output charge density of the nanogenerator. These results provide a guide to design the state-of-the-art nanogenerator for efficient mechanical energy harvesting.

Using methanol as a sustainable C1 source, cobalt-catalyzed α-methoxymethylation and α-aminomethylation of ketones have been developed. With cheap CoCl2·6H2O as catalyst and TBHP as oxidant, the methoxymethylated products were obtained within a short reaction time in up to 91% yield. Based on the observed reversibility of methoxy adduct to enone, the α-aminomethylation of ketones was then achieved by a one-pot methylenation/aza-Michael addition sequence. In addition, an easy way to convert α-methoxymethyl ketones to α-aminomethyl ketones has been discovered.

Chronic diseases are currently posing a major challenge not only to our life expectancy and healthspan but also to the healthcare system, as patients will need continual monitoring, treatment, and care to mitigate some of the severe health complications that may arise. Merely frequent visits to medical facilities and clinics may not be sufficient. Home‐based point‐of‐care diagnosis and monitoring may be needed for the prevention and/or management of long‐term complications. Recent advances in materials, fabrication methods, and bioelectronics have led to some epidermal systems that can measure critical physiological parameters and provide long‐term monitoring of several chronic diseases. In this review, it is systematically outlined the progress of epidermal bioelectronics aimed at managing common chronic diseases, such as cardiovascular diseases, diabetes, and chronic wounds. Flexible and stretchable materials with related engineering approaches that render wearability are also discussed. Finally, a list of current challenges, future perspectives as well as potential research directions with the aim towards better translation in bringing these wearable technologies from the laboratory to the clinic and market are presented. This review outlines the progress of epidermal bioelectronics aimed at managing common chronic diseases. Flexible and stretchable materials with related engineering approaches are also discussed. Finally, the review ends with current challenges, future perspectives, as well as potential research directions with the aim of better translation of wearable technologies and bringing them from the laboratory to the clinic and market.

Flexible pressure sensors possess promising applications in artificial electronic skin, intelligence robot, wearable health monitoring, flexible physiological signal sensing, etc. Herein, we design a flexible pressure sensor with robust stability, high sensitivity, and large linear pressure region on the basis of tetrafluoroethylene–hexafluoropropylene–vinylide (THV)/cyclic olefin copolymer (COC) piezoelectret nanogenerator. According to the theoretical analysis for piezoelectret nanogenerators with imbalanced charge distribution, THV and COC are utilized to promote the electric field inside the piezoelectret for output voltage enhancement. Meanwhile, the compression property of the piezoelectret nanogenerator is facilely tuned. Owing to high inner electric field and optimized compression property, the THV/COC piezoelectret nanogenerator exhibits a high sensitivity of 30 mV/kPa, which is 10 times higher than that of the traditional cellular polypropylene piezoelectret. Simultaneously, the linear pressure region reaches 150 kPa with excellent linearity (R2= 0.99963). The device is demonstrated to realize wearable pressure sensing with a wide pressure range from finger typing to fist hammering. This study presents a fabrication strategy for piezoelectret nanogenerators with high sensitivity and large linear pressure region, paving the way for development of wearable and flexible pressure sensing networks.

ABSTRACTLong non-coding RNAs (lncRNAs) can actively participate in tumorigenesis in various cancers. However, the involvement of lncRNA long stress induced non-coding transcripts 5 (LSINCT5) in non-small cell lung cancer (NSCLC) remains largely unknown. Here we showed a novel lncRNA signature in NSCLC through lncRNA profiling. Increased LSINCT5 expression positively correlates with malignant clinicopathological features and poor survival. LSINCT5 can promote migration and viability of various NSCLC cells in vitroand also enhance lung cancer progression in vivo. RNA immunoprecipitation followed by mass spectrometry has identified that LSINCT5 interacts with HMGA2. This physical interaction can increase the stability of HMGA2 by inhibiting proteasome-mediated degradation. Therefore, LSINCT5 may possibly contribute to NSCLC tumorigenesis by stabilizing the oncogenic factor of HMGA2. This novel LSINCT5/HMGA2 axis can modulate lung cancer progression and might be a promising target for pharmacological intervention.

Advances in mobile networks and low-power electronics have driven smart mobile medical devices at a tremendous pace, evoking increased interest in household healthcare, especially for those with cardiovascular or respiratory disease. Thus, flexible battery-free pressure sensors, with great potential for monitoring respiration and heartbeat in a smart way, are urgently demanded. However, traditional flexible battery-free pressure sensors for subtle physiological signal detecting are mostly tightly adhered onto the skin instead of working under the pressure of body weight in a noncontact mode, as the low sensitivity in the high-pressure region can hardly meet the demands. Moreover, a hollow microstructure (HM) with higher deformation than solid microstructures and great potential for improving the pressure sensitivity of self-powered sensors has never been investigated. Here, for the first time, we demonstrated a noncontact heartbeat and respiration monitoring system based on a flexible HM-enhanced self-powered pressure sensor, which possesses the advantages of low cost, a high dynamic-pressure sensitivity of 18.98 V·kPa–1, and a wide working range of 40 kPa simultaneously. Specific superiority of physiological detection under a high pressure is also observed. Continuous reliable heartbeat and respiration information is successfully detected in a noncontact mode and transmitted to a mobile phone.

Wearable active sensors have extensive applications in mobile biosensing and human–machine interaction but require good flexibility, high sensitivity, excellent stability, and self-powered feature. In this work, cellular polypropylene (PP) piezoelectret was chosen as the core material of a sensitivity-enhanced wearable active voiceprint sensor (SWAVS) to realize voiceprint recognition. By virtue of the dipole orientation control method, the air layers in the piezoelectret were efficiently utilized, and the current sensitivity was enhanced (from 1.98 pA/Hz to 5.81 pA/Hz at 115 dB). The SWAVS exhibited the superiorities of high sensitivity, accurate frequency response, and excellent stability. The voiceprint recognition system could make correct reactions to human voices by judging both the password and speaker. This study presented a voiceprint sensor with potential applications in noncontact biometric recognition and safety guarantee systems, promoting the progress of wearable sensor networks.

Wearable healthcare devices with monitoring, treating and protecting applications can provide reliable and newfangled interactive service for people. Herein, a bi-functional smart face mask based on electrospun polyetherimide (PEI) electret nonwoven is developed. By virtue of the surplus charges maintained steadily in the PEI nonwoven, the smart face mask possesses bi-functions of removing the particulate matter and generating electricity. Moreover, the unique applications for dynamically monitoring the particulate matter removal ability and human's respiratory rates are demonstrated. Besides offering an unique air filter, this study will promisingly promote the progress of self-powered wearable electronics.

•Graphene-based metal complexes of carbohydrazide were tested by DSC/TGA and FTIR.•Isoconversional and Combined kinetic method are used to calculate the Ea.•The concentrations of gaseous products are different depending on the metal types.

The photoswitching behaviors of heteroaryl azos and azobenzenes have attracted considerable interest due to their applications from material science to pharmacology. However, the use of UV light limits their application, especially in biomedicine and photopharmacology. In this work, using several aromaticity descriptors, including anisotropy of the induced current density analysis and nucleus-independent chemical shifts, we systematically investigate the relationship between anti-aromaticity and the absorption of a series of heterocyclic azos. We have demonstrated that the antiaromatic heterocycles substituted with diazenes enable the significant red shifts of the n → π* and π → π* transition bands of Eand Zisomers via density functional theory calculations. Moreover, introducing substituents into heterocycles could further tune the absorption. Finally, the λmaxof the first transition bands of the E(ca. 1026 nm) and Zisomers (ca. 1167 nm) of azos is achieved in the near-infrared region.