Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 201
Filtrar
1.
Expert Opin Biol Ther ; : 1-9, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38905143

RESUMEN

BACKGROUND: This study compared the pharmacokinetics (PK), immunogenicity, and safety of candidate tocilizumab biosimilar, CT-P47, administered via auto-injector (CT-P47 AI) or pre-filled syringe (CT-P47 PFS), in healthy Asian adults. RESEARCH DESIGN AND METHODS: In this phase I, multicenter, open-label study, participants were randomized 1:1 to receive a single 162 mg/0.9 mL dose of CT-P47 via AI or PFS. Primary endpoints were area under the concentration - time curve from time zero to infinity (AUC0-inf) and maximum serum concentration (Cmax). PK equivalence was determined if 90% confidence intervals (CIs) for the ratios of geometric least-squares means (gLSMs) were within the predefined 80-125% equivalence margin. Secondary PK parameters, immunogenicity, and safety outcomes were also assessed. RESULTS: Of 314 participants randomized (155 CT-P47 AI; 159 CT-P47 PFS), 310 received the study drug (153 CT-P47 AI; 157 CT-P47 PFS). Primary and secondary PK results, immunogenicity and safety were similar between groups. Ninety percent CIs for the ratio of gLSMs were within the predefined equivalence margin for AUC0-inf (85.87-102.94) and Cmax (82.98-98.16). CONCLUSIONS: PK equivalence between CT-P47 AI and CT-P47 PFS was demonstrated in healthy Asian adults, with comparable immunogenicity and safety between the two devices. TRIAL REGISTRATION: ClinicalTrials.gov: NCT05617183.


Tocilizumab is a biologic medicine used to treat inflammatory diseases, such as rheumatoid arthritis. A biosimilar is a drug that is an almost identical copy of an approved original ('reference') biologic medicine; it has identical efficacy and safety to the original medicine but is typically less expensive. CT­P47 is in development as a possible tocilizumab biosimilar.Some patients prefer injections using an auto-injector (AI) rather than a pre-filled syringe (PFS), for reasons including ease of use and convenience. With an AI, medicine is delivered automatically by firmly pressing the device against the skin, whereas, with a PFS, a needle is inserted into the skin and medicine delivered by depressing the plunger. The injection of CT­P47 using a PFS has shown comparable pharmacokinetics (i.e., the uptake, metabolism and excretion of the drug by the body) and safety to tocilizumab. Therefore, if the pharmacokinetics and safety of CT­P47 administered via AI and PFS were shown to be similar, this might expand the choice of administration devices available to patients.In this study, 310 healthy adults received a single injection of CT­P47 via AI or PFS. Blood samples were taken over 43 days to analyze pharmacokinetics. The uptake, metabolism and elimination of CT­P47 by the body was similar when administered by each device, suggesting that CT­P47 can be administered by either AI or PFS.

2.
ACS Omega ; 9(13): 15328-15338, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38585066

RESUMEN

The highly enantioselective synthesis of (R)-sitagliptin has been achieved through a series of key steps, including the aza-Michael addition and Baeyer-Villiger oxidation. The enantioselective aza-Michael addition involved the reaction of tert-butyl ß-naphthylmethoxycarbamate with (E)-1-(4-methoxyphenyl)-4-(2,4,5-trifluorophenyl)but-2-en-1-one, utilizing a quinine-derived C(9)-urea ammonium catalyst under phase-transfer catalytic conditions. The aza-Michael addition successfully introduced chirality to the amine in (R)-sitagliptin with 96% ee. The subsequent Baeyer-Villiger oxidation of the aza-Michael adduct led to the formation of 4-methoxyphenyl ester. Hydrolysis and amide coupling were then employed to construct the amide moiety. Further deprotections were performed to complete the synthesis of (R)-sitagliptin (7 steps, 41%, 96% ee).

3.
Brain Stimul ; 17(2): 405-412, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38537689

RESUMEN

Transcranial focused ultrasound (tFUS) neuromodulation emerges as a promising non-invasive approach for improving neurological conditions. Extinction of conditioned fear has served as a prime model for exposure-based therapies for anxiety disorders. We investigated whether tFUS stimulation to a critical brain area, the infralimbic subdivision of the prefrontal cortex (IL), could facilitate fear extinction using rats. In a series of experiments, tFUS was delivered to the IL of a freely-moving rat and compared to sham stimulation (tFUS vs. SHAM). Initially, Fos expression in the IL was measured shortly after the stimulation. The results show that Fos expression was significantly increased in the IL but not in the neighboring regions compared to SHAM. Subsequently, two groups of rats were subjected to fear conditioning, extinction, and retention while receiving stimulation during the extinction. Rats in the tFUS group froze significantly less than SHAM during both extinction and retention tests. Importantly, the reduced freezing in the tFUS group was not attributable to non-specific effect such as auditory noise, as both groups demonstrated a similar level of locomotive activity in an open field regardless of the stimulation condition. Finally, we replicated the procedure with a shortened conditioning-to-extinction interval (15 min) to induce immediate extinction deficit. The tFUS group showed a facilitated reduction in freezing during the extinction, which persisted in the subsequent retention session compared to SHAM. In summary, the current findings suggest that tFUS stimulation in the IL facilitates fear extinction, offering a potential therapeutic regimen for fear-related psychiatric disorders.


Asunto(s)
Extinción Psicológica , Miedo , Corteza Prefrontal , Animales , Miedo/fisiología , Extinción Psicológica/fisiología , Ratas , Masculino , Corteza Prefrontal/fisiología , Ratas Sprague-Dawley , Condicionamiento Clásico/fisiología
4.
J Struct Biol ; 216(2): 108086, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38527711

RESUMEN

Staphylococcus aureus, an ESKAPE pathogen, is a major clinical concern due to its pathogenicity and manifold antimicrobial resistance mechanisms. The commonly used ß-lactam antibiotics target bacterial penicillin-binding proteins (PBPs) and inhibit crosslinking of peptidoglycan strands that comprise the bacterial cell wall mesh, initiating a cascade of effects leading to bacterial cell death. S. aureus PBP1 is involved in synthesis of the bacterial cell wall during division and its presence is essential for survival of both antibiotic susceptible and resistant S. aureus strains. Here, we present X-ray crystallographic data for S. aureus PBP1 in its apo form as well as acyl-enzyme structures with distinct classes of ß-lactam antibiotics representing the penicillins, carbapenems, and cephalosporins, respectively: oxacillin, ertapenem and cephalexin. Our structural data suggest that the PBP1 active site is readily accessible for substrate, with little conformational change in key structural elements required for its covalent acylation of ß-lactam inhibitors. Stopped-flow kinetic analysis and gel-based competition assays support the structural observations, with even the weakest performing ß-lactams still having comparatively high acylation rates and affinities for PBP1. Our structural and kinetic analysis sheds insight into the ligand-PBP interactions that drive antibiotic efficacy against these historically useful antimicrobial targets and expands on current knowledge for future drug design and treatment of S. aureus infections.


Asunto(s)
Proteínas de Unión a las Penicilinas , Staphylococcus aureus , Staphylococcus aureus/metabolismo , Proteínas de Unión a las Penicilinas/metabolismo , Proteínas de Unión a las Penicilinas/química , Proteínas de Unión a las Penicilinas/genética , Cristalografía por Rayos X , Cinética , Antibacterianos/farmacología , Antibacterianos/química , beta-Lactamas/farmacología , beta-Lactamas/metabolismo , beta-Lactamas/química , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/química , Dominio Catalítico , Conformación Proteica , Modelos Moleculares
5.
Nat Mater ; 23(5): 664-669, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38413811

RESUMEN

Solvation dynamics critically affect charge transport. Spectroscopic experiments and computer simulations show that these dynamics in aqueous systems occur on a picosecond timescale. In the case of organic electrolytes, however, conflicting values ranging from 1 to several 100 picoseconds have been reported. We resolve this conflict by studying mixtures of an organic polymer and a lithium salt. Lithium ions coordinate with multiple polymer chains, resulting in temporary crosslinks. Relaxation of these crosslinks, detected by quasielastic neutron scattering, are directly related to solvation dynamics. Simulations reveal a broad spectrum of relaxation times. The average timescale for solvation dynamics in both experiment and simulation is one nanosecond. We present the direct measurement of ultraslow dynamics of solvation shell break-up in an electrolyte.

6.
PLoS One ; 18(11): e0294576, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38011085

RESUMEN

We investigated the attributes and attribute levels that affect researcher preferences for chemical compounds. We conducted a conjoint analysis on survey data of Korean researchers using chemical compounds from the Korean Chemical Bank (KCB). The analysis estimated the part-worth utility for each attribute's level, calculated relative importance of attributes, and classified user segmentation with different patterns. The results show that the structure database offers the highest part-worth utility to researchers, followed by high new functionality, price, screening service, and drug action data provided only by the KCB. Notably, researchers view the offer of a structured database and high new functionality as more important than other attributes in decision-making about research and development of chemical compounds. Furthermore, the results of segmentation analysis demonstrated that researchers have distinct usage patterns of chemical compounds: researchers consider structure database and high new functionality in cluster 1; and high new functionality and price in cluster 2, to be the most appealing. We discussed some policy and strategic implications based on the findings of this study and proposed some limitations.


Asunto(s)
Manejo de Datos , Prioridad del Paciente , Humanos , Encuestas y Cuestionarios , Investigadores
7.
Sci Rep ; 13(1): 20988, 2023 11 28.
Artículo en Inglés | MEDLINE | ID: mdl-38017045

RESUMEN

Despite the prevalent expression of freezing behavior following Pavlovian fear conditioning, a growing body of literature suggests potential sex differences in defensive responses. Our study investigated how female defensive behaviors are expressed in different threat situations and modulated by the estrous cycle. We aimed to compare freezing and flight-like responses during the acquisition and retrieval of fear conditioning using two distinct unconditioned stimuli (US) in two different spatial configurations: (1) electrical footshock (FUS) in a small, conventional enclosure with a grid floor, and (2) a predator-like robot (PUS) in a spacious, open arena. Fear conditioning with FUS showed no substantial differences between male and female rats of two different estrous cycles (proestrus and diestrus) in the levels of freezing and flight. However, when PUS was employed, proestrus female rats showed significantly more flight responses to the CS during both acquisition and the retrieval compared to the male and diestrus female rats. Taken together, our findings suggest that hormonal influences on the choice of defensive strategies in threat situations are significantly modulated by both the type of US and the spatial configuration of the environment.


Asunto(s)
Condicionamiento Clásico , Ciclo Estral , Ratas , Femenino , Masculino , Animales , Ciclo Estral/fisiología , Miedo/fisiología , Proestro/fisiología , Conducta Animal/fisiología
8.
Molecules ; 28(20)2023 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-37894485

RESUMEN

Lowering blood cholesterol levels is crucial for reducing the risk of cardiovascular disease in patients with familial hypercholesterolemia. To develop Perilla frutescens (L.) Britt. leaves as a functional food with a cholesterol-lowering effect, in this study, we collected P. frutescens (L.) Britt. leaves from different regions of China and Republic of Korea. On the basis of the extraction yield (all components; g/kg), we selected P. frutescens (L.) Britt. leaves from Hebei Province, China with an extract yield of 60.9 g/kg. After evaluating different concentrations of ethanol/water solvent for P. frutescens (L.) Britt. leaves, with luteolin 7-glucuronide as the indicator component, we selected a 30% ethanol/water solvent with a high luteolin 7-glucuronide content of 0.548 mg/g in Perilla. frutescens (L.) Britt. leaves. Subsequently, we evaluated the cholesterol-lowering effects of P. frutescens (L.) Britt. leaf extract and luteolin 7-glucuronide by detecting total cholesterol in HepG2 cells. The 30% ethanol extract lowered cholesterol levels significantly by downregulating 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase expression. This suggests that P. frutescens (L.) Britt leaves have significant health benefits and can be explored as a potentially promising food additive for the prevention of hypercholesterolemia-related diseases.


Asunto(s)
Perilla frutescens , Humanos , Glucurónidos , Luteolina , Extractos Vegetales/farmacología , Solventes , Etanol , Colesterol , Agua , Hojas de la Planta
9.
ACS Macro Lett ; 12(9): 1244-1250, 2023 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-37639325

RESUMEN

Solvation structure plays a crucial role in determining ion transport in electrolytes. We combine wide-angle X-ray scattering (WAXS) and molecular dynamics (MD) simulation to identify the solvation cage structure in two polymer electrolytes, poly(pentyl malonate) (PPM) and poly(ethylene oxide) (PEO) mixed with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt. As the salt concentration increases, the amorphous halo in the pure polymers is augmented by an additional peak at low scattering angles. The location of this peak and its height are, however, different in the two electrolytes. By decoupling the total intensity into species contributions and mapping scattering peaks to position-space molecular correlations, we elucidate distinct origins of the additional peak. In PPM, it arises from long-range charge-ordering between solvation cages and anions, while in PEO it is dominated by correlations between anions surrounding the same cage. TFSI- ions are present in the PPM solvation cage, but expelled from the PEO solvation cage.

10.
Emerg Microbes Infect ; 12(2): 2246594, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37555275

RESUMEN

Antivirals with broad coronavirus activity are important for treating high-risk individuals exposed to the constantly evolving SARS-CoV-2 variants of concern (VOCs) as well as emerging drug-resistant variants. We developed and characterized a novel class of active-site-directed 3-chymotrypsin-like protease (3CLpro) inhibitors (C2-C5a). Our lead direct-acting antiviral (DAA), C5a, is a non-covalent, non-peptide with a dissociation constant of 170 nM against recombinant SARS-CoV-2 3CLpro. The compounds C2-C5a exhibit broad-spectrum activity against Omicron subvariants (BA.5, BQ.1.1, and XBB.1.5) and seasonal human coronavirus-229E infection in human cells. Notably, C5a has median effective concentrations of 30-50 nM against BQ.1.1 and XBB.1.5 in two different human cell lines. X-ray crystallography has confirmed the unique binding modes of C2-C5a to the 3CLpro, which can limit virus cross-resistance to emerging Paxlovid-resistant variants. We tested the effect of C5a with two of our newly discovered host-directed antivirals (HDAs): N-0385, a TMPRSS2 inhibitor, and bafilomycin D (BafD), a human vacuolar H+-ATPase [V-ATPase] inhibitor. We demonstrated a synergistic action of C5a in combination with N-0385 and BafD against Omicron BA.5 infection in human Calu-3 lung cells. Our findings underscore that a SARS-CoV-2 multi-targeted treatment for circulating Omicron subvariants based on DAAs (C5a) and HDAs (N-0385 or BafD) can lead to therapeutic benefits by enhancing treatment efficacy. Furthermore, the high-resolution structures of SARS-CoV-2 3CLpro in complex with C2-C5a will facilitate future rational optimization of our novel broad-spectrum active-site-directed 3C-like protease inhibitors.


Asunto(s)
COVID-19 , Hepatitis C Crónica , Humanos , Inhibidores de Proteasas/farmacología , Antivirales/farmacología , SARS-CoV-2
11.
Nutr Res Pract ; 17(3): 421-437, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37266111

RESUMEN

BACKGROUND/OBJECTIVES: Chronic or intermittent hyperglycemia is associated with the development of diabetic complications. Oxidative stress and inflammation can be altered by hyperglycemia in diverse tissues, including kidneys and eyes, and play a pivotal role in diabetic complications. Our previous studies showed that the water-insoluble 5,7-dihydroxyflvone chrysin effectively combats diabetic damages incurred in diabetic kidneys and retinas. The current study employed the newly-synthesized 5.7-di-O-acetylchrysin, having higher solubility than chrysin, to compare the effects on diabetes-associated renal fibrosis and abnormal retinal neovascularization. MATERIALS/METHODS: In the in vivo study, db/db mice as animal models of type 2 diabetes were orally administrated 10 mg/kg BW diacetylchrysin, daily for 10 weeks. RESULTS: Unlike chrysin, oral administration of 10 mg/kg diacetylchrysin did not lower the blood glucose level and 24 h urine volume in db/db mice. Nevertheless, the urinary albumin excretion was markedly reduced. The administration of diacetylchrysin also diminished the deposition of collagen fibers in diabetic glomeruli and tubules by suppressing the induction of connective tissue growth factor and collagen IV in diabetic kidneys. Supplying diacetylchrysin enhanced the membrane type-1 matrix metalloproteinase (MMP) expression reduced in diabetic kidneys, while the tissue inhibitor of MMP-2 induction was attenuated in diacetylchrysin-challenged diabetic kidneys. In addition, supplementing diacetylchrysin to diabetic mice ameliorated renal injury due to glomerulosclerosis and tubular interstitial fibrosis. Furthermore, the reduced retinal inductions of Zonula occludens-1 and vascular endothelial cadherin in db/db mice were elevated in the retinal tissues of diacetylchrysin-treated animals. Oral administration of diacetylchrysin curtailed the induction of vascular endothelial growth factor (VEGF) and VEGF receptor 2 in db/db mice, ultimately retarding diabetes-associated retinal neovascularization. Additionally, the retinal formation of acellular capillaries with leaky vessels was reduced in diacetylchrysin-treated db/db mice. CONCLUSION: Diacetylchrysin may act as a potent pro-health agent for treating renal fibrosis-associated diabetic nephropathy and retinal neovascularization-associated diabetic retinopathy.

12.
ACS Macro Lett ; 12(7): 915-920, 2023 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-37363940

RESUMEN

Hexagonally packed (HEX) cylindrical microdomains can be obtained through the self-assembly of block copolymers (BCPs) with a moderately asymmetric volume fraction of one block (f), resulting in the formation of minor cylinders. However, for next-generation lithography and high-density memory devices, it is desirable to obtain densely and tetragonally packed inverted cylindrical microdomains, which are composed of the major block in the minor matrix. The inverted cylinders differ from conventional HEX cylinders, which consist of the minor block in the matrix of the major block. In this study, we achieved this objective by utilizing a binary blend of a polystyrene-b-poly(4-vinylpyridine) copolymer (S4VP) and polystyrene-b-poly(4-hydroxystyrene) copolymer (SHS), where the P4VP block exhibited a strong hydrogen bonding interaction with the PHS block. By carefully controlling the molecular weight ratio of S4VP and SHS as well as the blend composition, we successfully observed tetragonally packed inverted PS cylinders with a square cross-section at a volume fraction of PS of 0.69.

13.
Nanoscale Adv ; 5(9): 2565-2572, 2023 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-37143805

RESUMEN

Non-noble transition metal hydroxides have been widely used in electrochemical devices because of low cost and multiple redox states. In particular, self-supported porous transition metal hydroxides are used to improve the electrical conductivity, as well as achieving fast electron and mass transfer and a large effective surface area. Herein, we introduce facile synthesis of self-supported porous transition metal hydroxides using a poly(4-vinyl pyridine) (P4VP) film. We used metal cyanide as a transition metal precursor capable of forming metal hydroxide anions in aqueous solution, which is the seed for transition metal hydroxides. To increase the coordination between P4VP and the transition metal cyanide precursors, we dissolved the precursors in buffer solutions with various pH. When the P4VP film was immersed in the precursor solution with lower pH, the metal cyanide precursors were sufficiently coordinated with the protonated nitrogen in P4VP. When reactive ion etching was performed on the precursor-containing P4VP film, the P4VP region without coordination was etched out and became pores. Then, the coordinated precursors were aggregated as metal hydroxide seeds and became the metal hydroxide backbone, resulting in the formation of porous transition metal hydroxide structures. We successfully fabricated various self-supported porous transition metal hydroxides (Ni(OH)2, Co(OH)2, and FeOOH). Finally, we prepared a pseudo-capacitor based on self-supported porous Ni(OH)2, which showed a good specific capacitance (780 F g-1 at 5 A g-1).

14.
J Med Chem ; 66(11): 7553-7569, 2023 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-37235809

RESUMEN

We tested a series of SQ109 analogues against Mycobacterium tuberculosis and M. smegmatis, in addition to determining their uncoupling activity. We then investigated potential protein targets, involved in quinone and cell wall biosynthesis, using "rescue" experiments. There was little effect of menaquinone on growth inhibition by SQ109, but there were large increases in the IC50 of SQ109 and its analogues (up to 20×) on addition of undecaprenyl phosphate (Up), a homologue of the mycobacterial decaprenyl (C50) diphosphate. Inhibition of an undecaprenyl diphosphate phosphatase, an ortholog of the mycobacterial phosphatase, correlated with cell growth inhibition, and we found that M. smegmatis cell growth inhibition could be well predicted by using uncoupler and Up-rescue results. We also investigated whether SQ109 was metabolized inside Mycobacterium tuberculosis, finding only a single metabolite, previously shown to be inactive. The results are of general interest since they help explain the mechanism of SQ109 in mycobacteria.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis , Humanos , Antituberculosos/farmacología , Antituberculosos/metabolismo , Difosfatos/farmacología , Tuberculosis/tratamiento farmacológico , Tuberculosis/microbiología , Mycobacterium smegmatis
16.
BioDrugs ; 37(3): 433-440, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36881323

RESUMEN

BACKGROUND: The Phase 3 CT-P6 3.2 study demonstrated equivalent efficacy and comparable safety between CT-P6 and reference trastuzumab in patients with human epidermal growth factor receptor-2 (HER2)-positive early breast cancer after up to 3 years' follow-up. OBJECTIVE: To investigate long-term survival with CT-P6 and reference trastuzumab. METHODS: In the CT-P6 3.2 study, patients with HER2-positive early breast cancer were randomised to neoadjuvant chemotherapy with CT-P6 or reference trastuzumab, surgery, and adjuvant CT-P6 or reference trastuzumab before a 3-year post-treatment follow-up. Patients who completed the study could enter a 3-year extension (CT-P6 4.2 study). Data were collected every 6 months to assess overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS). RESULTS: Of 549 patients enrolled in the CT-P6 3.2 study, 216 (39.3%) patients continued in the CT-P6 4.2 study (CT-P6, 107; reference trastuzumab, 109) (intention-to-treat extension set). Median follow-up was 76.4 months for both groups. Medians were not reached for time-to-event parameters; estimated hazard ratios (95% confidence intervals) for CT-P6 versus reference trastuzumab were 0.59 (0.17-2.02) for OS, 1.07 (0.50-2.32) for DFS, and 1.08 (0.50-2.34) for PFS. Corresponding 6-year survival rates in the CT-P6 and reference trastuzumab groups, respectively, were 0.96 (0.90-0.99) and 0.94 (0.87-0.97), 0.87 (0.78-0.92) and 0.89 (0.81-0.94), and 0.87 (0.78-0.92) and 0.89 (0.82-0.94). CONCLUSIONS: Data from this extended follow-up of the CT-P6 3.2 study demonstrate the comparable long-term efficacy of CT-P6 and reference trastuzumab up to 6 years. EUDRACT NUMBER: 2019-003518-15 (retrospectively registered 10 March 2020).


Asunto(s)
Biosimilares Farmacéuticos , Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Estudios de Seguimiento , Trastuzumab , Receptor ErbB-2/metabolismo , Biosimilares Farmacéuticos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico
17.
J Chem Inf Model ; 63(7): 2158-2169, 2023 04 10.
Artículo en Inglés | MEDLINE | ID: mdl-36930801

RESUMEN

The rapid global spread of the SARS-CoV-2 virus facilitated the development of novel direct-acting antiviral agents (DAAs). The papain-like protease (PLpro) has been proposed as one of the major SARS-CoV-2 targets for DAAs due to its dual role in processing viral proteins and facilitating the host's immune suppression. This dual role makes identifying small molecules that can effectively neutralize SARS-CoV-2 PLpro activity a high-priority task. However, PLpro drug discovery faces a significant challenge due to the high mobility and induced-fit effects in the protease's active site. Herein, we virtually screened the ZINC20 database with Deep Docking (DD) to identify prospective noncovalent PLpro binders and combined ultra-large consensus docking with two pharmacophore (ph4)-filtering strategies. The analysis of active compounds revealed their somewhat-limited diversity, likely attributed to the induced-fit nature of PLpro's active site in the crystal structures, and therefore, the use of rigid docking protocols poses inherited limitations. The top hits were assessed against recombinant viral proteins and live viruses, demonstrating desirable inhibitory activities. The best compound VPC-300195 (IC50: 15 µM) ranks among the top noncovalent PLpro inhibitors discovered through in silico methodologies. In the search for novel SARS-CoV-2 PLpro-specific chemotypes, the identified inhibitors could serve as diverse templates for the development of effective noncovalent PLpro inhibitors.


Asunto(s)
COVID-19 , Hepatitis C Crónica , Humanos , SARS-CoV-2 , Antivirales/farmacología , Antivirales/química , Modelos Moleculares , Estudios Prospectivos , Inhibidores de Proteasas/farmacología , Inhibidores de Proteasas/química , Proteínas Virales/química , Péptido Hidrolasas
18.
Nature ; 614(7946): 81-87, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36725999

RESUMEN

Micro-LEDs (µLEDs) have been explored for augmented and virtual reality display applications that require extremely high pixels per inch and luminance1,2. However, conventional manufacturing processes based on the lateral assembly of red, green and blue (RGB) µLEDs have limitations in enhancing pixel density3-6. Recent demonstrations of vertical µLED displays have attempted to address this issue by stacking freestanding RGB LED membranes and fabricating top-down7-14, but minimization of the lateral dimensions of stacked µLEDs has been difficult. Here we report full-colour, vertically stacked µLEDs that achieve, to our knowledge, the highest array density (5,100 pixels per inch) and the smallest size (4 µm) reported to date. This is enabled by a two-dimensional materials-based layer transfer technique15-18 that allows the growth of RGB LEDs of near-submicron thickness on two-dimensional material-coated substrates via remote or van der Waals epitaxy, mechanical release and stacking of LEDs, followed by top-down fabrication. The smallest-ever stack height of around 9 µm is the key enabler for record high µLED array density. We also demonstrate vertical integration of blue µLEDs with silicon membrane transistors for active matrix operation. These results establish routes to creating full-colour µLED displays for augmented and virtual reality, while also offering a generalizable platform for broader classes of three-dimensional integrated devices.

19.
Nat Neurosci ; 26(4): 696-710, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36804648

RESUMEN

Stably recording the electrical activity of the same neurons over the adult life of an animal is important to neuroscience research and biomedical applications. Current implantable devices cannot provide stable recording on this timescale. Here, we introduce a method to precisely implant electronics with an open, unfolded mesh structure across multiple brain regions in the mouse. The open mesh structure forms a stable interwoven structure with the neural network, preventing probe drifting and showing no immune response and neuron loss during the year-long implantation. Rigorous statistical analysis, visual stimulus-dependent measurement and unbiased, machine-learning-based analysis demonstrated that single-unit action potentials have been recorded from the same neurons of behaving mice in a very long-term stable manner. Leveraging this stable structure, we demonstrated that the same neurons can be recorded over the entire adult life of the mouse, revealing the aging-associated evolution of single-neuron activities.


Asunto(s)
Encéfalo , Neurociencias , Ratones , Animales , Encéfalo/fisiología , Neuronas/fisiología , Potenciales de Acción/fisiología , Electrodos Implantados
20.
ACS Appl Mater Interfaces ; 15(2): 3266-3273, 2023 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-36598796

RESUMEN

Plasmonic broad-band absorbers have received much attention because of their high absorption and potential applications for light-absorbing devices such as thermophotovoltaics, solar energy harvesting, and thermal emitters. However, the fabrication of complex structures in a large area and thermostability remains a great challenge. Here, we report a titanium nitride nanoring broad-band absorber that has over 95% average absorption in the visible and near-infrared regions (400-900 nm). Nanoring structures in a large area (inch2) are fabricated by shadow sphere lithography, which can innovatively increase fabrication efficiency. The nanoring absorber showed over 2.3 times higher-temperature increases than flat film under the irradiation of light. These large-scale and broad-band absorbers have potential applications for solar energy conversion devices such as thermophotovoltaics and photothermal devices.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA