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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a lipid-enveloped virus that acquires its lipid bilayer from the host cell it infects. SARS-CoV-2 can spread from cell to cell or from patient to patient by undergoing assembly and budding to form new virions. The assembly and budding of SARS-CoV-2 is mediated by several structural proteins known as envelope (E), membrane (M), nucleoprotein (N), and spike (S), which can form virus-like particles (VLPs) when co-expressed in mammalian cells. Assembly and budding of SARS-CoV-2 from the host ER-Golgi intermediate compartment is a critical step in the virus acquiring its lipid bilayer. To date, little information is available on how SARS-CoV-2 assembles and forms new viral particles from host membranes. In this study, we used several lipid binding assays and found the N protein can strongly associate with anionic lipids including phosphoinositides and phosphatidylserine. Moreover, we show lipid binding occurs in the N protein C-terminal domain, which is supported by extensive in silico analysis. We demonstrate anionic lipid binding occurs for both the free and the N oligomeric forms, suggesting N can associate with membranes in the nucleocapsid form. Based on these results, we present a lipid-dependent model based on in vitro, cellular, and in silico data for the recruitment of N to assembly sites in the lifecycle of SARS-CoV-2.
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SARS-CoV-2 , SARS-CoV-2/metabolismo , Humanos , Proteínas de la Nucleocápside de Coronavirus/metabolismo , Proteínas de la Nucleocápside de Coronavirus/química , Proteínas de la Nucleocápside de Coronavirus/genética , COVID-19/metabolismo , COVID-19/virología , Lípidos de la Membrana/metabolismo , Ensamble de Virus , Nucleoproteínas/metabolismo , Nucleoproteínas/química , Fosfatidilserinas/metabolismo , Fosfatidilserinas/química , Aniones/metabolismo , Fosfoproteínas/metabolismo , Fosfoproteínas/química , Membrana Celular/metabolismo , Betacoronavirus/metabolismoRESUMEN
Hundreds of members have been synthesized and versatile applications have been promised for endofullerenes (EFs) in the past 30 y. However, the formation mechanism of EFs is still a long-standing puzzle to chemists, especially the mechanism of embedding clusters into charged carbon cages. Here, based on synthesis and structures of two representative vanadium-scandium-carbido/carbide EFs, VSc2C@Ih (7)-C80 and VSc2C2@Ih (7)-C80, a reasonable mechanism-C1 implantation (a carbon atom is implanted into carbon cage)-is proposed to interpret the evolution from VSc2C carbido to VSc2C2 carbide cluster. Supported by theoretical calculations together with crystallographic characterization, the single electron on vanadium (V) in VSc2C@Ih (7)-C80 is proved to facilitate the C1 implantation. While the V=C double bond is identified for VSc2C@Ih (7)-C80, after C1 implantation the distance between V and C atoms in VSc2C2@Ih (7)-C80 falls into the range of single bond lengths as previously shown in typical V-based organometallic complexes. This work exemplifies in situ self-driven implantation of an outer carbon atom into a charged carbon cage, which is different from previous heterogeneous implantation of nonmetal atoms (Group-V or -VIII atoms) driven by high-energy ion bombardment or high-pressure offline, and the proposed C1 implantation mechanism represents a heretofore unknown metal-carbon cluster encapsulation mechanism and can be the fundamental basis for EF family genesis.
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Fluorination is a useful approach for tailoring the physicochemical properties of nanocarbon materials. However, owing to the violent reactivity of fluorination, achieving edge-perfluorination of nanographene while maintaining its original π-conjugated structure is challenging. Instead of using traditional fluorination, here, we employed a bottom-up strategy involving fluorine preinstallation and synthesized decafluorinated and perfluorinated warped nanographenes (DFWNG and PFWNG, respectively) through a 10-fold Suzuki-Miyaura coupling followed by a harsh Scholl reaction, whereby precisely edge-perfluorinated nanographene with an intact π-conjugated structure was achieved for the first time. X-ray crystallography confirmed the intact π-conjugated structure and more twisted saddle-shaped geometry of PFWNG compared to that of DFWNG. Dynamic study revealed that the 26-ring carbon framework of PFWNG is less flexible than that of DFWNG and the pristine WNG, enabling chirality resolution of PFWNG and facilitating the achievement of CD spectra at -10 °C. The edge-perfluorination of PFWNG resulted in improved solubility, lower lowest unoccupied molecular orbital, and a surface electrostatic potentials/dipole moment direction opposite those of the pristine WNG. Likely owing to its intact π-conjugated structure, PFWNG exhibits comparable electron mobility with well-known PC61BM. Furthermore, perfluorination improves thermal stability and hydrophobicity, making PFWNG suitable for use as a thermostable/hydrophobic n-type semiconductor material. In the future, this fluorination strategy can be used to synthesize other perfluorinated nanocarbon materials, such as perfluorinated graphene nanoribbons and porous nanocarbon.
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This study aims to describe the distribution characteristics of voriconazole (VRC) plasma trough concentrations (Ctrough) in patients with liver dysfunction, identify factors influencing VRC Ctrough, and provide recommendations for the use of VRC in this population. We retrospectively collected medical records of hospitalized patients with liver dysfunction who used VRC and underwent therapeutic drug monitoring (TDM) at the First Hospital of Changsha. The severity of liver dysfunction was assessed by the Child-Pugh (CP) score. Multiple linear regression was employed to explore factors affecting VRC Ctrough in these patients. A total of 147 Ctrough from 102 patients with liver dysfunction were analyzed. Patients were categorized into a control group (n = 40), CP-A (n = 39), CP-B (n = 11), and CP-C group (n = 12). The initial probability of target attainment of Ctrough was 70.6%, with 6.9% of patients obtaining subtherapeutic Ctrough and 22.5% obtaining supertherapeutic Ctrough. The initial Ctrough in CP-A and B were 5.05 (0.64-9.57) mg/L and 5.37 (0.26-10.01) mg/L, respectively, significantly higher than the control group (P = 0.021 and P = 0.010). The proportion of VRC Ctrough of >5.5 mg/L in CP-A and B was 33.3% and 45.5%, respectively. Multiple linear regression analysis revealed that factors such as age ≥70 years, CP class, C-reactive protein (CRP), and direct bilirubin were significantly related to the initial VRC Ctrough. Among all measurements, patients with severe inflammation (CRP >100 mg/L), aged ≥70 years, and albumin levels of <30 or <25 g/L had significantly higher VRC Ctrough. The treatment success rate of VRC was 69.6% (71 of 102), and the rate of VRC-related adverse drug reactions was 29.4% (30 of 102). The recommended half-maintenance dose may lead to elevated VRC Ctrough in patients with CP-A and CP-B. TDM is essential for patients with advanced age, severe infections, or hypoalbuminemia to prevent excessive VRC trough levels.
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Renal cell carcinoma (RCC) is a malignant tumor originating from the epithelial cells of the renal tubules. The clear cell RCC subtype is closely linked to a poor prognosis due to its rapid progression. Circular RNA (circRNA) is a novel class of regulatory RNA molecules that play a role in the development of ccRCC, although their functions have not been fully elucidated. In this study, we identified a significant downregulation of circ-IP6K2 in ccRCC tissues based on data from the GSE100186 dataset. The decreased expression of circ-IP6K2 correlated with the progression of TNM stage and histological grade, and was also associated with decreased overall survival rates in ccRCC patients. Moreover, our findings revealed that circ-IP6K2 expression suppressed proliferation, migration, and invasion capabilities in vitro, and inhibited xenograft growth in vivo. Mechanistically, circ-IP6K2 acted as a sponge for miR-1292-5p in ccRCC cells, which in turn targeted the 3'UTR of CAMK2N1, leading to a decrease in its expression. CAMK2N1 was identified as a tumor suppressor that negatively regulated the ß-catenin/c-Myc oncogenic signaling pathway. Additionally, we confirmed a positive correlation between the expression of circ-IP6K2 and CAMK2N1 in ccRCC. Circ-IP6K2 functions to impede the progression of ccRCC by modulating the miR-1292-5p/CAMK2N1 axis. These findings shed new light on the molecular mechanisms driving ccRCC progression and suggest potential therapeutic targets for the treatment of ccRCC.
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Carcinoma de Células Renales , Neoplasias Renales , MicroARNs , Fosfotransferasas (Aceptor del Grupo Fosfato) , ARN Circular , Animales , Femenino , Humanos , Masculino , Ratones , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/patología , Carcinoma de Células Renales/metabolismo , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Progresión de la Enfermedad , Regulación Neoplásica de la Expresión Génica , Neoplasias Renales/genética , Neoplasias Renales/patología , Neoplasias Renales/metabolismo , Ratones Desnudos , MicroARNs/genética , MicroARNs/metabolismo , ARN Circular/genética , ARN Circular/metabolismo , Transducción de Señal , Fosfotransferasas (Aceptor del Grupo Fosfato)/genética , Fosfotransferasas (Aceptor del Grupo Fosfato)/metabolismoRESUMEN
The development of high-performance organic photovoltaic materials is of crucial importance for the commercialization of organic solar cells (OSCs). Herein, two structurally simple donor-π-conjugated linker-acceptor (D-π-A)-configured small-molecule donors with methyl-substituted triphenylamine as D unit, 1,1-dicyanomethylene-3-indanone as A unit, and thiophene or furan as π-conjugated linker, named DTICPT and DTICPF, are developed. DTICPT and DTICPF are facilely prepared via a two-step synthetic process with simple procedures. DTICPF with a furan π-conjugated linker exhibits stronger and broader optical absorption, deeper highest occupied molecular orbital (HOMO) energy levels, and better charge transport, compared to its thiophene analog DTICPT. As a result, vacuum-deposited OSCs based on DTICPF: C70 show an impressive power conversion efficiency (PCE) of 9.36% (certified 9.15%) with short-circuit current density (Jsc) up to 17.49 mA cm-2 (certified 17.56 mA cm-2), which is the highest Jsc reported so far for vacuum-deposited OSCs. Besides, devices based on DTICPT: C70 and DTICPF: C70 exhibit excellent long-term stability under different aging conditions. This work offers important insights into the rational design of D-π-A configured small-molecule donors for high efficient and stable vacuum-deposited OSCs.
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Heat shock protein 90 (Hsp90) is a tumor marker that accelerates cancer growth by disrupting protein homeostasis. However, concerns such as low clinical efficacy and drug resistance continue to be obstacles to the successful marketing of Hsp90 inhibitors. The cytoprotective function of autophagy has been identified as one of the mechanisms by which tumor cells gain resistance to chemotherapy. JD-02 was identified as a new Hsp90 inhibitor that suppressed colorectal cancer (CRC) growth by lowering client protein levels in vivo and in vitro. We found that JD-02 increased cellular autophagy, which inhibited apoptosis. JD-02 enhanced cytoprotective autophagy and regulated apoptotic suppression by increasing intracellular reactive oxygen species and inhibiting SRC protein levels, as demonstrated by quantitative proteomics, bioinformatic analysis, western blotting, and flow cytometry. This effect was reversed by autophagy inhibition. Therefore, due to the synergistic effects of Hsp90 and autophagy inhibitors in efficiently activating apoptotic pathways, they could potentially serve as promising therapeutic options for CRC.
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Autofagia , Neoplasias Colorrectales , Proteínas HSP90 de Choque Térmico , Especies Reactivas de Oxígeno , Animales , Humanos , Ratones , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Proteínas HSP90 de Choque Térmico/metabolismo , Ratones Endogámicos BALB C , Ratones Desnudos , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/efectos de los fármacos , Familia-src Quinasas/metabolismo , Familia-src Quinasas/antagonistas & inhibidores , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
RATIONALE: In clinical diagnosis of liver injury, which is an important health concern, serum aminotransferase assays have been the go-to method used worldwide. However, the measurement of serum enzyme activity has limitations, including inadequate disease specificity and enzyme specificity. METHODS: With the high selectivity and specificity provided by nano liquid chromatography-tandem mass spectrometry (LC/MS/MS), this work describes a method for the simultaneous determination of six proteins in liver that can be potentially used as biomarkers for liver injury: glutamic-pyruvic transaminase 1 (GPT1), glutamic oxaloacetic transaminase 1 (GOT1), methionine adenosyl transferase 1A (MAT1A), glutathione peroxidase 1 (GPX1), cytokeratin 18 (KRT18) and apolipoprotein E (APOE). RESULTS: In validation, the method was shown to have good selectivity and sensitivity (limits of detection at pg/mL level). The analytical method revealed that, compared with normal mice, in carbon tetrachloride-induced acute liver injury mice, liver MAT1A and GPX1 were significantly lower (p < 0.01 and p < 0.05, respectively), KRT18 was significantly higher (p < 0.05) and APOE and GPT1 were marginally significantly lower (p between 0.05 and 0.1). This is the first work reporting the absolute contents of GPT1, GOT1, MAT1A, GPX1 and KRT18 proteins based on LC/MS. CONCLUSIONS: The proposed method provides a basis for establishing more specific diagnostic indicators of liver injury.
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Hígado , Espectrometría de Masas en Tándem , Animales , Ratones , Espectrometría de Masas en Tándem/métodos , Cromatografía Liquida/métodos , Hígado/metabolismo , Apolipoproteínas E/metabolismoRESUMEN
OBJECTIVE: To investigate the influence of hyperglycemia on motor symptoms, especially axial signs, and potential mechanisms related to insulin resistance (IR) in patients with Parkinson's disease (PWP). METHODS: According to glycated hemoglobin (HbA1c) level, PWP were divided into the low-HbA1c and the high-HbA1c groups. Demographic information, glucose metabolism-related variables, Hoehn-Yahr stage, and motor function were compared between the two groups. Correlations between levels of HbA1c and the homeostatic model assessment (HOMA)-IR and motor function in PWP were further analyzed. RESULTS: HbA1c level was significantly and positively correlated with the Movement Disorder Society Unified Parkinson's Disease Rating Scale Part III score, axial signs subscore, the Timed Get Up and Go test time, the center of pressure displacement of standing with eyes open and closed, and significantly and negatively correlated with the 10-m walk test comfortable gait speed. HOMA-IR level was significantly and negatively correlated with 10-m walk test comfortable gait speed, but not with others. CONCLUSIONS: PWP with high HbA1c showed worse axial symptoms, including dysfunction of automatic walking, dynamic balance, and postural control than those with low HbA1c. In PWP, the effects of hyperglycemia on automatic walking speed may be associated with the IR-related mechanisms, and the effects on dynamic balance and postural control may be related to mechanisms other than IR.
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Hiperglucemia , Resistencia a la Insulina , Enfermedad de Parkinson , Humanos , Hemoglobina Glucada , Enfermedad de Parkinson/complicaciones , Caminata , Hiperglucemia/complicaciones , Equilibrio Postural/fisiologíaRESUMEN
Amorphophallus muelleri is an Araceae plant with perennial tuber, widely used in food, pharmaceutical and chemical industry due to its richness in glucomannan. In April 2022, an outbreak of a target spot on A. muelleri plantlets was observed in a nursery in Ruili, Yunnan, China. The leafstalks of the diseased plantlets in the nursery turned brown and decayed (Fig.1 A-B), then gradually some water-soaked spots on the true leaves developed along the veins (Fig.1 A). Subquencely, the spots on the true leaves turned dark green to white-grayish in the center, which formed light to dark brown concentric rings with a target-like appearance surrounded by a yellow halo (Fig.1 C). When the temperature was 20-34â and the relatively humidity was 25-80%, dark-green to black sporodochia with white hypha appeared on the lower and upper leaf surfaces. Finally, 5-8% of the plants surveyed on 800 m2 of one-year-old plantlets in the nursery showed the symptoms and some plants with infected leafstalks would be death. Similar symptoms were also observed on about 10% of the transplanted plants surveyed on 12000 m2 (1.2 ha) of two-year-old plantlets in the field. Five diseased leaves from five distinct plantlets in the nursery were collected for pathogen isolation. Leaf pieces(5 x 5 mm) were cut from the edge of necrotic lesions, and surface-sterilized with 2.5% sodium hypochlorite for 1 min, 75% ethanol for 30 s, then rinsed 5 times by sterilized distilled water, finally put the leaf pieces on sterilized filter paper for 3-5 minutes to dry them and transferred onto potato dextrose agar (PDA) in petri dishes at 25â for three days. Five pure cultures identical to colony and conidial characteristics were isolated from five individual plants. The representative pure culture (M1) was grayish-white and circular colonies were 7.50 cm in diamter after 15 days at 25â, with dark green concentric rings of sporodochia, the dorsal view of the colonies were yellowish. Conidia were aseptate, smooth, cylindrical, 5.00-6.25 (5.71) x 1.25-1.67 (1.63) µm (n = 20) rounded at both ends. A spore suspension (1 x 106 spores/ml) was prepared by harvesting spores from 15-day-old cultures grown in the dark at 25â, then a thirty-ml of spore suspension was sprayed on the healthy leaves of 10 two-year-old plantlets. Thirty-ml of sterile water was sprayed on the healthy leaves of another 10 seedlings and used as the control. All seedlings were placed in a nursery at 20 to 34â and a relative humidity of 25 to 80%. Similar symptoms (Fig.1 D-F) to those observed in the nursery and field developed on all the 10 seedlings inoculated with M1 after two days, but not on the control leaves. The pathogenicity tests were repeated for three times. Fungal cultures reisolated from the infected leaves were identical to the original colonies and conidia, completing Koch's postulates. The internal transcribed spacer (ITS, primers ITS1 and ITS4) region of ribosomal DNA (OQ553785), calmodulin (cmdA, primers CAL-228F and CAL2Rd)(OQ559103), RNA polymerase II second largest subunit (rpb2, primers RPB2-5F2 and RPB2-7cR) (OQ559104) and ß-tubulin (tub2, primers Bt2a and Bt2b) (OQ559105) of M1 had 100%, 98.52%, 98.98% and 98.98% identity with the sequences of Paramyrothecium breviseta CBS544.75 (KU846289 for ITS, KU846262 for cmdA, KU846351 for rpb2, and KU846406 for tub2), respectively. In the phylogenic tree based on ITS, cmdA, rpb2 and tub2 gene sequences, the pure culture M1 clustered with P. breviseta CBS544.75, SDBR-CMU387, DRL4 and DRL3, which has been reported as the pathogen of leaf spot of Coffea arabica in China, C. canephora in China and Thailand (Wu et al. 2021; Withee et al. 2022). Molecular and morphological observations showed the pure culture M1 were P. breviseta (Withee et al. 2022), in addition the disease was named as target spot dueing to the typical target symptom on the leaves. To our knowledge, this is the first report of P. breviseta on A. muelleri from Yunnan, China, as well as worldwide. This disease can caused serious economic losses of A. muelleri dueing to that it can result 5-8% death of the plants in the nursery.
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Hole transport materials (HTMs) are essential for improving the stability and efficiency of perovskite solar cells (PSCs). In this study, we have designed and synthesized a novel organic small molecule HTM, cor-(DPA)5, characterized by a bowl-shaped core with symmetric five diphenylamine groups. Compared to already-known HTMs, the bowl-shaped and relatively compact structure of cor-(DPA)5 facilitates intermolecular π-π interactions, promotes film formations, and enhances charge transport. Consequently, the cor-[DPA(2)]5 HTM exhibits high charge mobility, exceptional hydrophobicity, and a significantly elevated glass transition temperature. Superior to previously reported HTMs such as spiro-OMeTAD and cor-OMePTPA, our newly synthesized cor-(DPA)5 HTM is free from any ionic dopants. As a result, the dopant-free cor-[DPA(2)]5-based PSC demonstrates an impressive efficiency of 24.01%, and exhibits outstanding operational stability. It retains 96% after continuous exposure to 1 sun irradiation for 800 hours under MPP (maximum power point) tracking in ambient air. These findings present a structurally compact novel HTM and exemplify a new approach to the molecular design of HTM for the development of stable and effective PSCs.
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Endohedral metallofullerenes (EMFs) are sub-nano carbon materials with diverse applications, yet their formation mechanism, particularly for metastable isomers, remains ambiguous. The current theoretical methods focus mainly on the most stable isomers, leading to limited predictability of metastable ones due to their low stabilities and yields. Herein, we report the successful isolation and characterization of two metastable EMFs, Sc2C2@C1(39656)-C82 and Sc2C2@C1(51383)-C84, which violate the isolated pentagon rule (IPR). These two non-IPR EMFs exhibit a rare case of planar and pennant-like Sc2C2 clusters, which can be considered hybrids of the common butterfly-shaped and linear configurations. More importantly, the theoretical results reveal that despite being metastable, these two non-IPR EMFs survived as the products from their most stable precursors, Sc2C2@C2v(5)-C80 and Sc2C2@Cs(6)-C82, via a C2 insertion during the post-formation annealing stages. We propose a systematic theoretical method for predicting metastable EMFs during the post-formation stages. The unambiguous molecular-level structural evidence, combined with the theoretical calculation results, provides valuable insights into the formation mechanisms of EMFs, shedding light on the potential of post-formation mechanisms as a promising approach for EMF synthesis.
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Proteomics provides molecular bases of biology and disease, and liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a platform widely used for bottom-up proteomics. Data-independent acquisition (DIA) improves the run-to-run reproducibility of LC-MS/MS in proteomics research. However, the existing DIA data processing tools sometimes produce large deviations from true values for the peptides and proteins in quantification. Peak-picking error and incorrect ion selection are the two main causes of the deviations. We present a cross-run ion selection and peak-picking (CRISP) tool that utilizes the important advantage of run-to-run consistency of DIA and simultaneously examines the DIA data from the whole set of runs to filter out the interfering signals, instead of only looking at a single run at a time. Eight datasets acquired by mass spectrometers from different vendors with different types of mass analyzers were used to benchmark our CRISP-DIA against other currently available DIA tools. In the benchmark datasets, for analytes with large content variation among samples, CRISP-DIA generally resulted in 20 to 50% relative decrease in error rates compared to other DIA tools, at both the peptide precursor level and the protein level. CRISP-DIA detected differentially expressed proteins more efficiently, with 3.3 to 90.3% increases in the numbers of true positives and 12.3 to 35.3% decreases in the false positive rates, in some cases. In the real biological datasets, CRISP-DIA showed better consistencies of the quantification results. The advantages of assimilating DIA data in multiple runs for quantitative proteomics were demonstrated, which can significantly improve the quantification accuracy.
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Proteómica , Espectrometría de Masas en Tándem , Cromatografía Liquida/métodos , Proteómica/métodos , Espectrometría de Masas en Tándem/métodos , Reproducibilidad de los Resultados , Proteínas/análisis , Péptidos/química , Programas Informáticos , Proteoma/análisisRESUMEN
In-memory computing provides an opportunity to meet the growing demands of large data-driven applications such as machine learning, by colocating logic operations and data storage. Despite being regarded as the ultimate solution for high-density integration and low-power manipulation, the use of spin or electric dipole at the single-molecule level to realize in-memory logic functions has yet to be realized at room temperature, due to their random orientation. Here, we demonstrate logic-in-memory operations, based on single electric dipole flipping in a two-terminal single-metallofullerene (Sc2C2@Cs(hept)-C88) device at room temperature. By applying a low voltage of ±0.8 V to the single-metallofullerene junction, we found that the digital information recorded among the different dipole states could be reversibly encoded in situ and stored. As a consequence, 14 types of Boolean logic operation were shown from a single-metallofullerene device. Density functional theory calculations reveal that the non-volatile memory behaviour comes from dipole reorientation of the [Sc2C2] group in the fullerene cage. This proof-of-concept represents a major step towards room-temperature electrically manipulated, low-power, two-terminal in-memory logic devices and a direction for in-memory computing using nanoelectronic devices.
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Mangroves are frequently inundated with saline water and have evolved different anatomical and physiological mechanisms to filter and, in some species, excrete excess salt from the water they take up. Because salts impose osmotic stress, interspecific differences in salt tolerance and salt management strategy may influence physiological responses to drought throughout the entire plant hydraulic pathway, from roots to leaves. Here, we characterized embolism vulnerability simultaneously in leaves, stems, and roots of seedlings of two mangrove species (Avicennia marina and Bruguiera gymnorrhiza) along with turgor-loss points in roots and leaves and xylem anatomical traits. In both species, the water potentials causing 50% of total embolism were less negative in roots and leaves than they were in stems, but the water potentials causing incipient embolism (5%) were similar in roots, stems, and leaves. Stomatal closure in leaves and turgor loss in both leaves and roots occurred at water potentials only slightly less negative than the water potentials causing 5% of total embolism. Xylem anatomical traits were unrelated to vulnerability to embolism. Vulnerability segmentation may be important in limiting embolism spread into stems from more vulnerable roots and leaves. Interspecific differences in salt tolerance affected hydraulic traits from roots to leaves: the salt-secretor A. marina lost turgor at more negative water potentials and had more embolism-resistant xylem than the salt-excluder B. gymnorrhiza. Characterizing physiological thresholds of roots may help to explain recent mangrove mortality after drought and extended saltwater inundation.
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Avicennia , Xilema , Sequías , Hojas de la Planta/fisiología , Raíces de Plantas/fisiología , Tallos de la Planta , Árboles , Xilema/fisiologíaRESUMEN
Learning a many-body Hamiltonian from its dynamics is a fundamental problem in physics. In this Letter, we propose the first algorithm to achieve the Heisenberg limit for learning an interacting N-qubit local Hamiltonian. After a total evolution time of O(ε^{-1}), the proposed algorithm can efficiently estimate any parameter in the N-qubit Hamiltonian to ε error with high probability. Our algorithm uses ideas from quantum simulation to decouple the unknown N-qubit Hamiltonian H into noninteracting patches and learns H using a quantum-enhanced divide-and-conquer approach. The proposed algorithm is robust against state preparation and measurement error, does not require eigenstates or thermal states, and only uses polylog(ε^{-1}) experiments. In contrast, the best existing algorithms require O(ε^{-2}) experiments and total evolution time. We prove a matching lower bound to establish the asymptotic optimality of our algorithm.
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Sodium caprate (C10) has been widely evaluated as an intestinal permeation enhancer for the oral delivery of macromolecules. However, the effect of C10 on the intestinal absorption of peptides with different physicochemical properties and its permeation-enhancing effect in vivo remains to be understood. Here, we evaluated the effects of C10 on intestinal absorption in rats with a glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GIP-GLP1) dual agonist peptide (LY) and semaglutide with different enzymatic stabilities and self-association behaviors as well as the oral exposure of the LY peptide in minipigs. Furthermore, we investigated the mechanism of action (MoA) of C10 for improving the intestinal absorption of the LY peptide in vivo via live imaging of the rat intestinal epithelium and tissue distribution of the LY peptide in minipigs. The LY peptide showed higher proteolytic stability in pancreatin and was a monomer in solution compared to that in semaglutide. C10 increased in vitro permeability in the minipig intestinal organoid monolayer to a greater extent for the LY peptide than for semaglutide. In the rat jejunal closed-loop model, C10 increased the absorption of LY peptide better than that of semaglutide, which might be attributed to higher in vitro proteolytic stability and permeability of the LY peptide. Using confocal live imaging, we observed that C10 enabled the rapid oral absorption of a model macromolecule (FD4) in the rat intestine. In the duodenum tissues of minipigs, C10 was found to qualitatively reduce the tight junction protein level and allow peptide uptake to the intestinal cells. C10 decreased the transition temperature of the artificial lipid membrane, indicating an increase in membrane fluidity, which is consistent with the above in vivo imaging results. These data indicated that the LY's favorable physicochemical properties combined with the effects of C10 on the intestinal mucosa resulted in an â¼2% relative bioavailability in minipigs.
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Polipéptido Inhibidor Gástrico , Péptido 1 Similar al Glucagón , Porcinos , Ratas , Animales , Polipéptido Inhibidor Gástrico/metabolismo , Polipéptido Inhibidor Gástrico/farmacología , Péptido 1 Similar al Glucagón/metabolismo , Porcinos Enanos/metabolismo , Ácidos Decanoicos/farmacología , Absorción Intestinal , Mucosa Intestinal/metabolismo , Péptidos/metabolismoRESUMEN
The continuous evolution and spread of common pathogenic bacteria is a major challenge in diagnosis and treatment with current biotechnology and modern molecular medicine. To confront this challenge, scientists urgently need to find alternatives for traditional antimicrobial agents. Various bacteriostatic aptamers obtained through SELEX screening are one of the most promising strategies. These bacteriostatic aptamers can reduce bacterial infection by blocking bacterial toxin infiltration, inhibiting biofilm formation, preventing bacterial invasion of immune cells, interfering with essential biochemical processes, and other mechanisms. In addition, aptamers may also help enhance the function of other antibacterial materials/drugs when used in combination. This paper has reviewed the bacteriostatic aptamers in the treatment of common pathogenic bacteria infections. For this aspect, first, bacteriostatic aptamers and their screening strategies are summarized. Then, the effect of molecular tailoring and modification on the performance of the bacteriostatic aptamer is analyzed, and the antibacterial mechanism and antibacterial strategy based on aptamers are introduced. Finally, the key technical challenges and their development prospects in clinical treatment are also carefully discussed.
Asunto(s)
Aptámeros de Nucleótidos , Infecciones Bacterianas , Humanos , Aptámeros de Nucleótidos/farmacología , Aptámeros de Nucleótidos/uso terapéutico , Aptámeros de Nucleótidos/química , Infecciones Bacterianas/tratamiento farmacológico , Bacterias , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Técnica SELEX de Producción de Aptámeros/métodosRESUMEN
Phospholipase D (PLD) hydrolyzes membrane lipids to produce phosphatidic acid (PA), a lipid mediator involved in various cellular and physiological processes. Here, we show that PLDα6 and PA regulate the distribution of GIBBERELLIN (GA)-INSENSITIVE DWARF1 (GID1), a soluble gibberellin receptor in rice. PLDα6-knockout (KO) plants display less sensitivity to GA than WT, and PA restores the mutant to a normal GA response. PA binds to GID1, as documented by liposome binding, fat immunoblotting, and surface plasmon resonance. Arginines 79 and 82 of GID1 are two key amino acid residues required for PA binding and also for GID1's nuclear localization. The loss of PLDα6 impedes GA-induced nuclear localization of GID1. In addition, PLDα6-KO plants attenuated GA-induced degradation of the DELLA protein SLENDER RICE1 (SLR1). These data suggest that PLDα6 and PA positively mediate GA signaling in rice via PA binding to GID1 and promotion of its nuclear translocation.
Asunto(s)
Giberelinas , Oryza , Regulación de la Expresión Génica de las Plantas , Mutación , Oryza/genética , Ácidos Fosfatidicos , Fosfolipasas , Reguladores del Crecimiento de las Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas GenéticamenteRESUMEN
BACKGROUND AND AIMS: While genome size limits the minimum sizes and maximum numbers of cells that can be packed into a given leaf volume, mature cell sizes can be substantially larger than their meristematic precursors and vary in response to abiotic conditions. Mangroves are iconic examples of how abiotic conditions can influence the evolution of plant phenotypes. METHODS: Here, we examined the coordination between genome size, leaf cell sizes, cell packing densities and leaf size in 13 mangrove species across four sites in China. Four of these species occurred at more than one site, allowing us to test the effect of climate on leaf anatomy. RESULTS: We found that genome sizes of mangroves were very small compared to other angiosperms, but, like other angiosperms, mangrove cells were always larger than the minimum size defined by genome size. Increasing mean annual temperature of a growth site led to higher packing densities of veins (Dv) and stomata (Ds) and smaller epidermal cells but had no effect on stomatal size. In contrast to other angiosperms, mangroves exhibited (1) a negative relationship between guard cell size and genome size; (2) epidermal cells that were smaller than stomata; and (3) coordination between Dv and Ds that was not mediated by epidermal cell size. Furthermore, mangrove epidermal cell sizes and packing densities covaried with leaf size. CONCLUSIONS: While mangroves exhibited coordination between veins and stomata and attained a maximum theoretical stomatal conductance similar to that of other angiosperms, the tissue-level tradeoffs underlying these similar relationships across species and environments were markedly different, perhaps indicative of the unique structural and physiological adaptations of mangroves to their stressful environments.