Linear Non-benzenoid Isomer of Acene Fusing Chrysene with Azulene Units.

Non-benzenoid polycyclic aromatic hydrocarbons (PAHs) have received considerable attention owing to their distinctive optical and electrical properties. Nevertheless, the synthesis and optoelectronic application of non-benzenoid PAHs remain challenging. Herein, we present a facile synthesis of linear non-benzenoid PAH with an armchair edge, diACh, by fusing chrysene with two azulene units. We systematically investigated the optical and electrical properties, which were also compared to its isomers, including benzenoid and non-benzenoid zigzag edge isomers. diACh exhibits global aromaticity, good planarity, and suitable highest occupied molecular orbital/lowest unoccupied molecular orbital energy levels. The protonation of diACh in solution successively forms a stable tropylium cation and dication. Moreover, the neutral, cationic, and dicationic states of diACh can be transformed with remarkable reversibility during the protonation-deprotonation process, as confirmed by ultraviolet-visible absorptions, fluorescence spectra, 1H nuclear magnetic resonance, and theoretical calculations. Additionally, we fabricate p-type organic field-effect transistor (OFET) devices based on diACh with hole mobility up to 0.026 cm2 V-1 s-1, and we further develop OFET-based acid vapor sensors with good sensitivity, recyclability, and selectivity. These findings underscore the unique properties of linear non-benzenoid PAHs with an armchair edge engendered by the fusion of azulene with the acene backbone, showcasing prospective applications in organic optoelectronics.

Lignin-based vitrimer containing dynamic borate ester bonds with intrinsic photoconversion and excellent photothermal remoldability.

The development of photoresponsive shape memory materials based on the photothermal conversion properties of lignin and the low activation energy of the dynamic covalent borate bond is of great importance. In this paper, a kind of lignin-based vitrimer polymer (LBP) containing dynamic boronic ester bonds was prepared by a "sulfhydryl-epoxy" click reaction and etherification reaction. The results show that the rigid segment EP-EL (lignin-based epoxy resin) and BDB (2,2'-(1,4-phenylene)-bis-[4-mercapto-1,3,2-dioxaneborane]) with benzene ring structure can impart tensile strength (20.8 MPa) to the LBP, while the flexible segment PEG imparts good elongation at break (15 %). The dynamic binding and dissociation exchange mechanism of the boronic ester bonds enables LBP to exhibit thermal remodelling properties (up to 36.2 %) and water-assisted self-healing properties at room temperature (up to 49.0 %). In addition, LBP exhibits excellent thermal and light-responsive shape memory properties due to its own photothermal conversion performance (photothermal conversion efficiency up to 18.2 %) and the dynamic boronic ester bond thermal activation bond exchange mechanism. The insulating properties of LBP make it suitable for use in high temperature protection circuit devices and light-responsive circuit devices. This study provides new insights into the design and application of Vitrimer and photoresponsive shape memory polymers, and also offers a new avenue for high-value utilization of lignin.

Spiro-buckybowls: Synthesis and Selective Transformations toward Chiral and Nonlinear Optical Polycycles.

Integration of spirocycles with buckybowls is a promising strategy to construct three-dimensional (3D) curved π-systems and to endow distinctive physicochemical features arising from buckybowls. Herein, a series of carbon-bridged spiro-type heterosumanenes (spiro-HSEs) were synthesized by combining 9,9'-spirobifluorene and dichalcogenasumanenes (DCSs). It is found that spiro-conjugation plays an important role in the geometric and electronic structures of spiro-HSEs. The bowl depth of DCSs moiety becomes larger in the spiro-HSEs. Owing to the Jahn-Teller (J-T) effect, two DCSs segments of spiro-HSEs have different bowl depths accompanied with the unequal distribution of charge in radical cation state. Taking advantage of the typical reactions of DCSs, selective transformations of spiro-HSEs have been adopted in accordance to the nature of chalcogen atoms (S, Se, Te) to bestow the value-added functionalities. The emissive property is enhanced by converting the thiophene rings of S-doped spiro-HSE into thiophene S,S-dioxides. A chiroptical polycycle could be produced by ring-opening of the edge benzene of Se-doped spiro-HSE. The covalent adduct of Te-doped spiro-HSE with Br2 forms non-centrosymmetric halogen-bonded networks, resulting in the high performance second-order nonlinear optics (NLO).

Synthesis, Structures, and Properties for PIII-Doped Hetero-Buckybowls and Their Phosphonium Salts.

Doping polycyclic aromatic hydrocarbons with heteroatoms enables manipulation of their electronic structures. Herein, the structures and properties of phosphorus (P) doped heterosumanenes (HSEs) are regulated by varying the valence states of P-dopant. The phosphine sulfide (PV) and chalcogens (S, Se, Te) co-doped HSEs (1-3) are reduced to trivalent phosphorus (PIII) doped analogues 4-6. Then, the PIII-dopants on 4-6 are converted to phosphonium salts (R4P+), giving 7-9. The valence states of P-dopant show great influence on molecular geometries and electronic structures. Taking P and S co-doped HSEs as example, bowl-depths increase in the order of 1 (PV) < 7 (R4P+) < 4 (PIII), and the HOMO energy levels and HOMO-LUMO gaps increase to be 7 < 1 < 4. Consistent with the theoretical calculation, the first oxidation potentials decrease and the absorption/emission bands show blue shift from 7 to 1 to 4. The transformation of PV to PIII leads to large variations on the coordination with Ag+, owing to the alteration of coordination site from P=S to PIII. The phosphonium salts show ring-opening of phosphole rings under electrochemical reduction. It is found that chalcogen atoms play pivotal roles on coordination patterns of coordination complexes and the conversion rates of ring-opening reactions.

YTHDF1 facilitates esophageal cancer progression via augmenting m6A-dependent TINAGL1 translation.

N6-methyladenosine (m6A) is the most abundant internal RNA modification and plays a critical role in carcinogenesis and tumor progression. As a powerful m6A reader, YTHDF1 is implicated in multiple malignancies. However, the functions and underlying mechanisms of YTHDF1 in esophageal cancer (ESCA) are elusive. Here, we revealed that YTHDF1 expression was remarkably up-regulated in ESCA and linked with poor prognosis. Functionally, YTHDF1 promoted ESCA cell proliferation, migration, and metastasis in vitro and in vivo. Mechanistically, we demonstrated that TINAGL1 might be a potential target of YTHDF1. We revealed that YTHDF1 recognized and bound to m6A-modified sites of TINAGL1 mRNA, resulting in enhanced translation of TINAGL1. Furthermore, TINAGL1 knockdown partially rescued tumor-promoting effects of YTHDF1 overexpression. Therefore, we unveil that YTHDF1 facilitates ESCA progression by promoting TINAGL1 translation in an m6A-dependent manner, which offers an attractive therapeutic target for ESCA.

Multi-heterojunctioned plastics with high thermoelectric figure of merit.

Conjugated polymers promise inherently flexible and low-cost thermoelectrics for powering the Internet of Things from waste heat1,2. Their valuable applications, however, have been hitherto hindered by the low dimensionless figure of merit (ZT)3-6. Here we report high-ZT thermoelectric plastics, which were achieved by creating a polymeric multi-heterojunction with periodic dual-heterojunction features, where each period is composed of two polymers with a sub-ten-nanometre layered heterojunction structure and an interpenetrating bulk-heterojunction interface. This geometry produces significantly enhanced interfacial phonon-like scattering while maintaining efficient charge transport. We observed a significant suppression of thermal conductivity by over 60 per cent and an enhanced power factor when compared with individual polymers, resulting in a ZT of up to 1.28 at 368 kelvin. This polymeric thermoelectric performance surpasses that of commercial thermoelectric materials and existing flexible thermoelectric candidates. Importantly, we demonstrated the compatibility of the polymeric multi-heterojunction structure with solution coating techniques for satisfying the demand for large-area plastic thermoelectrics, which paves the way for polymeric multi-heterojunctions towards cost-effective wearable thermoelectric technologies.

Multi-Functional 2D Covalent Organic Frameworks with Diketopyrrolopyrrole as Electron Acceptor.

2D covalent organic framework (COF) materials with extended conjugated structure and periodic columnar π-arrays exhibit promising applications in organic optoelectronics. However, there is a scarcity of reports on optoelectronic COFs, mainly due to the lack of suitable π-skeletons. Here, two multi-functional optoelectronic 2D COFs DPP-TPP-COF and DPP-TBB-COF are constructed with diketopyrrolopyrrole as electron acceptor (A), and 1,3,6,8-tetraphenylpyrene and 1,3,5-triphenylbenzene as electron donor (D) through imine bonds. Both 2D COFs showed good crystallinities and AA stacking with a rhombic framework for DPP-TPP-COF and hexagonal one for DPP-TBB-COF, respectively. The electron D-A and ordered intermolecular packing structures endow the COFs with broad UV-vis absorptions and narrow bandgaps along with suitable HOMO/LUMO energy levels, resulting in multi-functional optoelectronic properties, including photothermal conversion, supercapacitor property, and ambipolar semiconducting behavior. Among them, DPP-TPP-COF exhibits a high photothermal conversion efficiency of 47% under 660 nm laser irradiation, while DPP-TBB-COF exhibits superior specific capacitance of 384 F g-1. Moreover, P-type doping and N-type doping are achieved by iodine and tetrakis(dimethylamino)ethylene on a single host COF, resulting in ambipolar semiconducting behavior. These results provide a paradigm for the application of multi-functional optoelectronic COF materials.

Vertical distribution of arsenic and bacterial communities in calcareous farmland amending by organic fertilizer and iron-oxidizing bacteria: Field experiment on concomitant remediation.

The migration and transformation mechanisms of arsenic (As) in soil environments necessitate an understanding of its influencing processes. Here, we investigate the subsurface biogeochemical transformation of As and iron (Fe) through amended in the top 20 cm with iron oxidizing bacteria (FeOB) and organic fertilizer (OF). Our comprehensive 400-day field study, conducted in a calcareous soil profile sectioned into 20 cm increments, involved analysis by sequential extraction and assessment of microbial properties. The results reveal that the introduction of additional OF increased the release ratio of As/Fe from the non-specific adsorption fraction (136.47 %) at the subsoil depth (40-60 cm), underscoring the importance of sampling at various depths and time points to accurately elucidate the form, instability, and migration of As within the profile. Examination of bacterial interaction networks indicated a disrupted initial niche in the bottom layer, resulting in a novel cooperative symbiosis. While the addition of FeOB did not lead to the dominance of specific bacterial species, it did enhance the relative abundance of As-tolerant Acidobacteria and Gemmatimonadetes in both surface (39.2 % and 38.76 %) and deeper soils (44.29 % and 23.73 %) compared to the control. Consequently, the amendment of FeOB in conjunction with OF facilitated the formation of poorly amorphous Fe (hydr)oxides in the soil, achieved through abiotic and biotic sequestration processes. Throughout the long-term remediation process, the migration coefficient of bioavailable As within the soil profile decreased, indicating that these practices did not exacerbate As mobilization. This study carries significant implications for enhancing biogeochemical cycling in As-contaminated Sierozem soils and exploring potential bioremediation strategies. ENVIRONMENTAL IMPLICATION: The long-term exposure of sewage irrigation has potential adverse effects on the local ecosystem, causing serious environmental problems. Microorganisms play a vital role in the migration and transformation of arsenic in calcareous soil in arid areas, which highlights the necessity of understanding its dynamics. The vertical distribution, microbial community and fate of arsenic in calcareous farmland soil profile in northwest China were studied through field experiments. The results of this work have certain significance for the remediation of arsenic-contaminated soil in arid areas, and provide new insights for the migration, transformation and remediation of arsenic in this kind of soil.

Pre-Endcapping of Hyperbranched Polymers toward Intrinsically Stretchable Semiconductors with Good Ductility and Carrier Mobility.

The advancement of semiconducting polymers stands as a pivotal milestone in the quest to realize wearable electronics. Nonetheless, endowing semiconductor polymers with stretchability without compromising their carrier mobility remains a formidable challenge. This study proposes a "pre-endcapping" strategy for synthesizing hyperbranched semiconducting polymers (HBSPs), aiming to achieve the balance between carrier mobility and stretchability for organic electronics. The findings unveil that the aggregates formed by the endcapped hyperbranched network structure not only ensure efficient charge transport but also demonstrate superior tensile resistance. In comparison to linear conjugated polymers, HBSPs exhibit substantially larger crack onset strains and notably diminished tensile moduli. It is evident that the HBSPs surpass their linear counterparts in terms of both their semiconducting and mechanical properties. Among HBSPs, HBSP-72h-2.5 stands out as the preeminent candidate within the field of inherently stretchable semiconducting polymers, maintaining 93% of its initial mobility even when subjected to 100% strain (1.41 ± 0.206 cm2 V-1 s-1). Furthermore, thin film devices of HBSP-72h-2.5 remain stable after undergoing repeated stretching and releasing cycles. Notably, the mobilities are independent of the stretching directions, showing isotropic charge transport behavior. The preliminary study makes this "pre-endcapping" strategy a potential candidate for the future design of organic materials for flexible electronic devices.

Arsenic and cadmium simultaneous immobilization in arid calcareous soil amended with iron-oxidizing bacteria and organic fertilizer.

Immobilization stands as the most widely adopted remediation technology for addressing heavy metal(loid) contamination in soil. However, it is crucial to acknowledge that this process does not eliminate pollutants; instead, it confines them, potentially leaving room for future mobilization. Presently, our comprehension of the temporal variations in the efficacy of immobilization, particularly in the context of its applicability to arid farmland, remains severely limited. To address this knowledge gap, our research delves deep into the roles of iron-oxidizing bacteria (FeOB) and organic fertilizer (OF) in the simultaneous immobilization of arsenic (As) and cadmium (Cd) in soils. We conducted laboratory incubation and field experiments to investigate these phenomena. When OF was combined with FeOB, a noteworthy transformation of available As and Cd into stable species, such as the residual state and combinations with Fe-Mn/Al oxides, was observed. This transformation coincided with changes in soil properties, including pH, Eh, soluble Fe, and dissolved organic carbon (DOC). Furthermore, we observed synergistic effects between available As and Cd when treated with bacteria and OF individually. The stabilization efficiency of As and Cd, as determined by the Toxicity Characteristic Leaching Procedure, reached its highest values at 33.39 % and 24.67 %, respectively, after 120 days. Nevertheless, the formation of iron­calcium complexes was disrupted due to pH fluctuations. Hence, long-term monitoring and model development are essential to enhance our understanding of the remediation process. The application of organic fertilizer and the use of FeOB in calcareous soil hold promise for the restoration of polluted soil and the maintenance of soil health by mitigating the instability of heavy metals(loid).

Radical Cation Salts of Hetera-Buckybowls: Polar Crystals, Negative Thermal Expansion and Phase Transition.

Radical cation salts of π-conjugated polycycles are rich in physical properties. Herein, two kinds of hetera-buckybowls, ethoxy-substituted trithiasumanene (3SEt) and triselenasumanene (3SeEt), are synthesized as electron donors. Galvanostatic oxidation of them affords radical cation salts (3SEt)5 (TTFMPB)3 , (3SeEt)5 (TTFMPB)3 , (3SEt)4 PMA, and (3SeEt)4 PMA, where PMA is Keggin-type phosphomolybdate and TTFMPB is tetrakis[3,5-bis(trifluoromethyl)-phenyl]borate. In these salts, 3SEt/3SeEt are partially charged and show distinct conformation change with the site charge and counter anions. In TTFMPB salts, (TTFMPB)- forms hexagonal channels that accommodate the packing columns of 3SEt/3SeEt. In particular, (3SEt)5 (TTFMPB)3 adopts the R3c space group and is a polar crystal with the columns of 3SEt all in the up-bowl direction. The PMA salts of 3SEt/3SeEt are polar crystals (C2 space group) with 3SEt/3SeEt being planar and forming columnar stacks. (3SeEt)4 PMA shows a structural modulation below 200 K, namely, negative thermal expansion (NTE) of the unit cell volume and enlargement of the intermolecular distances between neighboring 3SeEt molecules. The four salts are semiconductors with an activation energy of 0.18-0.38 eV. The conductivity of (3SeEt)4 PMA shows a reversible transition upon cooling and heating, in accordance to the NTE structural modulation. This work paves the way toward conducting materials based on hetera-buckybowls.

Evaluation of Rice Straw, Corncob, and Soybean Straw as Substrates for the Cultivation of Lepista sordida.

Lepista sordida is a type of high-quality rare edible and medicinal mushroom, and its research boom is just beginning. More than 80 million tons of grain crop residues are produced each year in Heilongjiang Province. To realize the exploration and utilization of wild L. sordida mushrooms and also provide a theoretical support for the high-value utilization of these resources in Heilongjiang Province, we evaluated the cultivation of L. sordida mushrooms using rice straw, corncob, and soybean straw as substrates. L. sordida grew on all three substrates, and the biological efficiency and yield of the mushrooms grown on soybean straw and corncob were 32.33 ± 1.78% and 4.20 ± 0.23 kg m-2, and 30.15 ± 0.93% and 3.92 ± 0.12 kg m-2, respectively, which increased by 9.38% and 2.08% compared with that on the rice straw substrate with 3.84 ± 0.12 kg m-2 and 29.56 ± 0.89%. The time it took for the mycelia to colonize and initiate primordia on the soybean straw substrate was 22.33 ± 0.58 d and 19.67 ± 0.58 d, respectively, which was delayed by 2 d and 3 d compared with that on the rice straw substrate with 20.67 ± 2.08 d and 16.33 ± 0.58 d, respectively. The fruiting bodies grown on corncob and soybean straw substrates were relatively larger than those on the rice straw substrate. The highest amount of crude protein was 57.38 ± 0.08 g 100 g-1, and the lowest amount of crude polysaccharide was 6.03 ± 0.01 g 100 g-1. They were observed on mushrooms collected from the corncob substrate. The contents of the heavy metal mercury, lead, arsenic, and cadmium in the fruiting bodies grown on each substrate were within the national safety range.

Phototunable and Photopatternable Polymer Semiconductors.

ConspectusIn recent decades, there has been rapid development in the field of polymer semiconductors, particularly those based on conjugated donor-acceptor (D-A) polymers exhibiting high charge mobilities. Furthermore, the application of polymer semiconductors has been successfully extended to a wide range of functional devices, including sensors, photodetectors, radio frequency identification (RFID) tags, electronic paper, skin electronics, and artificial synapses. Over the past few years, there has been a growing focus on stimuli-responsive polymer semiconductors, which have the potential to impart additional functionalities to conventional field-effect transistors, garnering increased attention within the research community. In this context, phototunable polymer semiconductors have received significant attention due to their ability to utilize light as an external stimulus, enabling remote control of device performance with high spatiotemporal resolution. Meanwhile, integration of field-effect transistors with polymer semiconductors can enable the realization of complex functions. To achieve this, precise and controllable patterning of polymer semiconductors becomes essential. In this Account, we discuss our research findings in the context of phototunable and photopatternable polymer semiconductors. These developments encompass the following key aspects: (i) polymer semiconductors, such as poly(diketopyrrolopyrrole-quaterthiophene) (PDPP4T), exhibit phototunability when blended with the photochromic compound hexaarylbiimidazole (HABI). The photo/thermal-responsive field-effect transistors (FETs) can be fabricated using blending thin films. Remarkably, these photo/thermal-responsive transistors can function as photonically programmable and thermally erasable nonvolatile memory devices. (ii) By incorporating photoswitchable groups like azo and spiropyran into the side chains of conjugated D-A polymers, we can create phototunable polymer semiconductors. The reversible isomerization of azo and spiropyran groups significantly influences the charge transport properties of these polymer semiconductors. Consequently, the performance of the resulting FETs can be reversibly tuned through UV/visible or near-infrared light (NIR) irradiation. Notably, the incorporation of two distinct azo groups into the side chains leads to polymer semiconductors with tristable semiconducting states, offering the ability to logically control device performance using light irradiation at three different wavelengths. (iii) Photopatterning of p-type, n-type, and ambipolar semiconductors featuring alkyl side chains can be achieved using a diazirine-based, four-armed photo-cross-linker (4CNN) with a loading concentration of no more than 3% (w/w). Furthermore, the semiconducting performances of FETs with patterned thin films were found to be satisfactorily uniform. Importantly, the cross-linked thin films are robust and show good resistance to organic solvents, which is useful for fabricating all-solution processable multilayer electronic devices. (iv) The introduction of azide groups into the side chains of conjugated polymers results in a single-component semiconducting photoresist. The presence of azide groups renders the side chains with photo-cross-linking ability, enabling the successful formation of uniform patterns, even as small as 5 µm, under UV light irradiation. Benefiting from the single component feature, field-effect transistors with individual patterned thin films display satisfactorily uniform performances. Moreover, this semiconducting photoresist has proven effective for efficiently photopatterning other polymer semiconductors, demonstrating its versatility.

Effects of Different Forms and Proportions of Nitrogen on the Growth, Photosynthetic Characteristics, and Carbon and Nitrogen Metabolism in Tomato.

Optimal plant growth in many species is achieved when the two major forms of N are supplied at a particular ratio. This study investigated optimal nitrogen forms and ratios for tomato growth using the 'Jingfan 502' tomato variety. Thirteen treatments were applied with varying proportions of nitrate nitrogen (NN), ammonium nitrogen (AN), and urea nitrogen (UN). Results revealed that the combination of AN and UN inhibited tomato growth and photosynthetic capacity. Conversely, the joint application of NN and UN or NN and AN led to a significant enhancement in tomato plant growth. Notably, the T12 (75%UN:25%NN) and T4 (75%NN:25%AN) treatments significantly increased the gas exchange and chlorophyll fluorescence parameters, thereby promoting the accumulation of photosynthetic products. The contents of fructose, glucose, and sucrose were significantly increased by 121.07%, 206.26%, and 94.64% and by 104.39%, 156.42%, and 61.40%, respectively, compared with those in the control. Additionally, AN favored starch accumulation, while NN and UN favored fructose, sucrose, and glucose accumulation. Gene expression related to nitrogen and sugar metabolism increased significantly in T12 and T4, with T12 showing greater upregulation. Key enzyme activity in metabolism also increased notably. In summary, T12 enhanced tomato growth by upregulating gene expression, increasing enzyme activity, and boosting photosynthesis and sugar accumulation. Growers should consider using NN and UN to reduce AN application in tomato fertilization.

Dual-Mode Conversion of Photodetector and Neuromorphic Vision Sensor via Bias Voltage Regulation on a Single Device.

Simultaneous implementation of photodetector and neuromorphic vision sensor (NVS) on a single device faces a great challenge, due to the inherent speed discrepancy in their photoresponse characteristics. In this work, a trench-bridged GaN/Ga2 O3 /GaN back-to-back double heterojunction array device is fabricated to enable the advanced functionalities of both devices on a single device. Interestingly, the device shows fast photoresponse and persistent photoconductivity behavior at low and high voltages, respectively, through the modulation of oxygen vacancy ionization and de-ionization processes in Ga2 O3 . Consequently, the role of the optoelectronic device can be altered between the photodetector and NVS by simply adjusting the magnitude of bias voltage. As a photodetector, the device is able to realize fast optical imaging and optical communication functions. On the other hand, the device exhibits outstanding image sensing, image memory, and neuromorphic visual pre-processing as an NVS. The utilization of NVS for image pre-processing leads to a noticeable enhancement in both recognition accuracy and efficiency. The results presented in this work not only offer a new avenue to obtain complex functionality on a single optoelectronic device but also provide opportunities to implement advanced robotic vision systems and neuromorphic computing.

Transforming Hetera-Buckybowls into Chiral Conjugated Polycycles Incorporating Epoxycyclooctadiene: a Two-Step Approach.

Chiral π-conjugated polycycles have garnered increasing attention due to versatile applications in optoelectronic materials and biological sciences. In this study, we report the synthesis of chiral π-conjugated polycycles incorporating a chiral epoxycyclooctadiene moiety. Our synthetic strategy capitalizes on the novel reactions of hetera-buckybowl triselenasumanene (TSS) and is achieved in two-step manner. Firstly, the TSS is regio-selectively transformed into its ortho-quinone form. Subsequently, the nucleophilic addition reactions of TSS ortho-quinone by phenylethynides are metal ion-dependent. When utilizing (phenylethynyl)magnesium bromide as the nucleophile, two phenylethynyls are furnished onto the edged benzene ring of TSS. When the nucleophile is (phenylethynyl)lithium, a cascade of nucleophilic addition, intermolecular electron-transfer, ring-opening, and tetradehydro-Diels-Alder (TDDA) reactions occur sequentially in one-pot, ultimately affording chiral π-conjugated polycycles featuring the epoxycyclooctadiene moiety as an integral part of their backbones. This work represents a step forward in the synthesis of chiral π-conjugated polycycles using TSS as synthon.

Clinical characteristics and proposed mechanism of pediatric spinal cord injury resulting from backbend practice.

Objective: Pediatric spinal cord injury without radiographic abnormality (SCIWORA) caused by backbend practice is increasing. This study proposed an underlying 'combined injury mechanism' related to the spinal cord and femoral nerve overstretching. Methods: Pediatric patients diagnosed with backbend-associated SCIWORA at the China Rehabilitation Research Center during 2017-2021 were recruited. Clinical and imaging data were collected, and each patient's clinical course and prognosis were determined. Healthy dancers were recruited to simulate the backbend, obtain images, and estimate the spinal cord and femoral nerve stretch ratio. A model for the 'combined injury mechanism' was established using 4-week-old SD rats. Results: Forty-two SCIWORA female patients with an average age of 6 (SD 1) years and an average hospitalization time of 91 (SD 43) days were assessed. The primary initial symptom was pain in the back and/or lower extremities (33, 79%). The average time from injury onset to severe paralysis was 2.0 (SD 0.6) hours. Most patients had complete paraplegia (32, 76%), and neurological levels were distributed mainly in thoracic segments (38, 91%). Patients with elicited tendon reflexes on admission tended to have an incomplete spinal cord injury (p = 0.001) and improved motor recovery (p = 0.018). After one year, the most common complications were scoliosis (31, 74%) and abnormal hips (14, 33%). Injury of the caudal spinal cord torn by nerve roots was confirmed by surgical exploration in a case. The thoracic spinal cord and femoral nerves were overstretched by 148.8 ± 3.6% and111.7 ± 4.0%, respectively, in a full backbend posture. The 'combined injury mechanism' was partially replicated in the animal model. Conclusion: Spinal overstretch and transient dislocation are considered the primary mechanisms by which SCIWORA occurs in children. Overstretching the femoral nerve aggravates spinal cord injuries caused by backbend practice.

[Electrocardiogram classification algorithm based on CvT-13 and multimodal image fusion].

Electrocardiogram (ECG) signal is an important basis for the diagnosis of arrhythmia and myocardial infarction. In order to further improve the classification effect of arrhythmia and myocardial infarction, an ECG classification algorithm based on Convolutional vision Transformer (CvT) and multimodal image fusion was proposed. Through Gramian summation angular field (GASF), Gramian difference angular field (GADF) and recurrence plot (RP), the one-dimensional ECG signal was converted into three different modes of two-dimensional images, and fused into a multimodal fusion image containing more features. The CvT-13 model could take into account local and global information when processing the fused image, thus effectively improving the classification performance. On the MIT-BIH arrhythmia dataset and the PTB myocardial infarction dataset, the algorithm achieved a combined accuracy of 99.9% for the classification of five arrhythmias and 99.8% for the classification of myocardial infarction. The experiments show that the high-precision computer-assisted intelligent classification method is superior and can effectively improve the diagnostic efficiency of arrhythmia as well as myocardial infarction and other cardiac diseases.

Inhibition of Dopamine Neurons Prevents Incentive Value Encoding of a Reward Cue: With Revelations from Deep Phenotyping.

The survival of an organism is dependent on its ability to respond to cues in the environment. Such cues can attain control over behavior as a function of the value ascribed to them. Some individuals have an inherent tendency to attribute reward-paired cues with incentive motivational value, or incentive salience. For these individuals, termed sign-trackers, a discrete cue that precedes reward delivery becomes attractive and desirable in its own right. Prior work suggests that the behavior of sign-trackers is dopamine-dependent, and cue-elicited dopamine in the NAc is believed to encode the incentive value of reward cues. Here we exploited the temporal resolution of optogenetics to determine whether selective inhibition of ventral tegmental area (VTA) dopamine neurons during cue presentation attenuates the propensity to sign-track. Using male tyrosine hydroxylase (TH)-Cre Long Evans rats, it was found that, under baseline conditions, ∼84% of TH-Cre rats tend to sign-track. Laser-induced inhibition of VTA dopamine neurons during cue presentation prevented the development of sign-tracking behavior, without affecting goal-tracking behavior. When laser inhibition was terminated, these same rats developed a sign-tracking response. Video analysis using DeepLabCutTM revealed that, relative to rats that received laser inhibition, rats in the control group spent more time near the location of the reward cue even when it was not present and were more likely to orient toward and approach the cue during its presentation. These findings demonstrate that cue-elicited dopamine release is critical for the attribution of incentive salience to reward cues.SIGNIFICANCE STATEMENT Activity of dopamine neurons in the ventral tegmental area (VTA) during cue presentation is necessary for the development of a sign-tracking, but not a goal-tracking, conditioned response in a Pavlovian task. We capitalized on the temporal precision of optogenetics to pair cue presentation with inhibition of VTA dopamine neurons. A detailed behavioral analysis with DeepLabCutTM revealed that cue-directed behaviors do not emerge without dopamine neuron activity in the VTA. Importantly, however, when optogenetic inhibition is lifted, cue-directed behaviors increase, and a sign-tracking response develops. These findings confirm the necessity of dopamine neuron activity in the VTA during cue presentation to encode the incentive value of reward cues.

Supramolecular Transistors with Quantum Interference Effect.

The charge transport through supramolecular junctions exhibits unique quantum interference (QI) effects, which provide an opportunity for the design of supramolecular transistors. Benefiting from the configuration dependence of QI, configuration control of the supramolecular assemblies to demonstrate the QI features is a key but challenging step. In this work, we fabricated the supramolecular transistors and investigated the charge transport through the conducting channel of the individual π-stacked thiophene/phenylene co-oligomers (TPCOs) using the electrochemically gated scanning tunneling microscope break junction technique. We controlled the configuration of the supramolecular channel and switched the QI features between the anti-resonance and resonance states of the supramolecular channels. We observed the supramolecular transistor with its on/off ratio above 103 (∼1300), a high gating efficiency of ∼165 mV/dec, a low off-state leakage current of ∼30 pA, and the channel length scaled down to <2.0 nm. Density functional theory calculations suggested that the QI features in π-stacked TPCOs vary depending on the supramolecular architecture and can be manipulated efficiently by fine-tuning the supramolecular configurations. This work reveals the potential of the supramolecular channels for molecular electronics and provides a fundamental understanding of intermolecular charge transport.