Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 279
Filtrar
Más filtros

País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Proc Natl Acad Sci U S A ; 121(8): e2313840121, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38354259

RESUMEN

Recent studies have reported the experimental discovery that nanoscale specimens of even a natural material, such as diamond, can be deformed elastically to as much as 10% tensile elastic strain at room temperature without the onset of permanent damage or fracture. Computational work combining ab initio calculations and machine learning (ML) algorithms has further demonstrated that the bandgap of diamond can be altered significantly purely by reversible elastic straining. These findings open up unprecedented possibilities for designing materials and devices with extreme physical properties and performance characteristics for a variety of technological applications. However, a general scientific framework to guide the design of engineering materials through such elastic strain engineering (ESE) has not yet been developed. By combining first-principles calculations with ML, we present here a general approach to map out the entire phonon stability boundary in six-dimensional strain space, which can guide the ESE of a material without phase transitions. We focus on ESE of vibrational properties, including harmonic phonon dispersions, nonlinear phonon scattering, and thermal conductivity. While the framework presented here can be applied to any material, we show as an example demonstration that the room-temperature lattice thermal conductivity of diamond can be increased by more than 100% or reduced by more than 95% purely by ESE, without triggering phonon instabilities. Such a framework opens the door for tailoring of thermal-barrier, thermoelectric, and electro-optical properties of materials and devices through the purposeful design of homogeneous or inhomogeneous strains.

2.
Small ; 20(24): e2309841, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38217292

RESUMEN

The demand for the exploration of highly active and durable electro/photocatalysts for renewable energy conversion has experienced a significant surge in recent years. Metal-organic frameworks (MOFs), by virtue of their high porosity, large surface area, and modifiable metal centers and ligands, have gained tremendous attention and demonstrated promising prospects in electro/photocatalytic energy conversion. However, the small pore sizes and limited active sites of 3D bulk MOFs hinder their wide applications. Developing 2D MOFs with tailored thickness and large aspect ratio has emerged as an effective approach to meet these challenges, offering a high density of exposed active sites, better mechanical stability, better assembly flexibility, and shorter charge and photoexcited state transfer distances compared to 3D bulk MOFs. In this review, synthesis methods for the most up-to-date 2D MOFs are first overviewed, highlighting their respective advantages and disadvantages. Subsequently, a systematic analysis is conducted on the identification and electronic structure modulation of catalytic active sites in 2D MOFs and their applications in renewable energy conversion, including electrocatalysis and photocatalysis (electro/photocatalysis). Lastly, the current challenges and future development of 2D MOFs toward highly efficient and practical electro/photocatalysis are proposed.

3.
Opt Lett ; 49(12): 3300-3303, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38875605

RESUMEN

Optical path length (OPL) noise resulting from stray light significantly constrains interferometry displacement measurements in the low-frequency band. This paper presents an analytical model considering the presence of stray light in heterodyne laser interferometers. Due to the cyclic nonlinear coupling effect, there will be some special OPLs of stray light, minimizing the frequency-mixing impact to zero. Consequently, we propose a noise suppression scheme that locks the OPL of stray light at the zero coupling point. Therefore, we significantly enhanced the interference displacement measurement noise within the low-frequency band. Experimental results show that the interferometer achieves a displacement noise level lower than 6 pm/Hz1/2 covering 1 mHz.

4.
BMC Cancer ; 24(1): 727, 2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38877445

RESUMEN

BACKGROUND: The Naples Prognostic Score (NPS), integrating inflammatory and nutritional biomarkers, has been reported to be associated with the prognosis of various malignancies, but there is no report on intrahepatic cholangiocarcinoma (ICC). This study aimed to explore the prognostic value of NPS in patients with ICC. METHODS: Patients with ICC after hepatectomy were collected, and divided into three groups. The prognosis factors were determined by Cox regression analysis. Predictive efficacy was evaluated by the time-dependent receiver operating characteristic (ROC) curves. RESULTS: A total of 174 patients were included (Group 1: 33 (19.0%) patients; Group 2: 83 (47.7%) patients; and Group 3: 58 (33.3%) patients). The baseline characteristics showed the higher the NPS, the higher the proportion of patients with cirrhosis and Child-Pugh B, and more advanced tumors. The Kaplan-Meier curves reflect higher NPS were associated with poor survival. Multivariable analysis showed NPS was an independent risk factor of overall survival (NPS group 2 vs. 1: HR = 1.671, 95% CI: 1.022-3.027, p = 0.009; NPS group 3 vs. 1: HR = 2.208, 95% CI: 1.259-4.780, p = 0.007) and recurrence-free survival (NPS group 2 vs. 1: HR = 1.506, 95% CI: 1.184-3.498, p = 0.010; NPS group 3 vs. 1: HR = 2.141, 95% CI: 2.519-4.087, P = 0.001). The time ROC indicated NPS was superior to other models in predicting prognosis. CONCLUSIONS: NPS is a simple and effective tool for predicting the long-term survival of patients with ICC after hepatectomy. Patients with high NPS require close follow-up, and improving NPS may prolong the survival time.


Asunto(s)
Neoplasias de los Conductos Biliares , Colangiocarcinoma , Hepatectomía , Humanos , Colangiocarcinoma/cirugía , Colangiocarcinoma/mortalidad , Colangiocarcinoma/patología , Masculino , Femenino , Persona de Mediana Edad , Pronóstico , Neoplasias de los Conductos Biliares/cirugía , Neoplasias de los Conductos Biliares/mortalidad , Neoplasias de los Conductos Biliares/patología , Anciano , Curva ROC , Estudios Retrospectivos , Estimación de Kaplan-Meier , Adulto , Factores de Riesgo
5.
Diabetes Obes Metab ; 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38828802

RESUMEN

AIM: To explore biomarkers that can predict the response of type 2 diabetes (T2D) patients to metformin at an early stage to provide better treatment for T2D. METHODS: T2D patients with (responders) or without response (non-responders) to metformin were recruited, and their serum samples were used for metabolomic analysis to identify candidate biomarkers. Moreover, the efficacy of metformin was verified by insulin-resistant mice, and the candidate biomarkers were verified to determine the biomarkers. Five different machine learning methods were used to construct the integrated biomarker profiling (IBP) with the biomarkers to predict the response of T2D patients to metformin. RESULTS: A total of 73 responders and 63 non-responders were recruited, and 88 differential metabolites were identified in the serum samples. After being verified in mice, 19 of the 88 were considered as candidate biomarkers. Next, after metformin regulation, nine candidate biomarkers were confirmed as the biomarkers. After comparing five machine learning models, the nine biomarkers were constructed into the IBP for predicting the response of T2D patients to metformin based on the Naïve Bayes classifier, which was verified with an accuracy of 89.70%. CONCLUSIONS: The IBP composed of nine biomarkers can be used to predict the response of T2D patients to metformin, enabling clinicians to start a combined medication strategy as soon as possible if T2D patients do not respond to metformin.

6.
Environ Sci Technol ; 58(9): 4127-4136, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38382014

RESUMEN

Tetrabromobisphenol A-bis(2,3-dibromo-2-methylpropyl ether) (TBBPA-DBMPE) has come into use as an alternative to hexabromocyclododecane (HBCD), but it is unclear whether TBBPA-DBMPE has less hazard than HBCD. Here, we compared the bioaccumulation and male reproductive toxicity between TBBPA-DBMPE and HBCD in mice following long-term oral exposure after birth. We found that the concentrations of TBBPA-DBMPE in livers significantly increased with time, exhibiting a bioaccumulation potency not substantially different from HBCD. Lactational exposure to 1000 µg/kg/d TBBPA-DBMPE as well as 50 µg/kg/d HBCD inhibited testis development in suckling pups, and extended exposure up to adulthood resulted in significant molecular and cellular alterations in testes, with slighter effects of 50 µg/kg/d TBBPA-DBMPE. When exposure was extended to 8 month age, severe reproductive impairments including reduced sperm count, increased abnormal sperm, and subfertility occurred in all treated animals, although 50 µg/kg/d TBBPA-DBMPE exerted lower effects than 50 µg/kg/d HBCD. Altogether, all data led us to conclude that TBBPA-DBMPE exerted weaker male reproductive toxicity than HBCD at the same doses but exhibited bioaccumulation potential roughly equivalent to HBCD. Our study fills the data gap regarding the bioaccumulation and toxicity of TBBPA-DBMPE and raises concerns about its use as an alternative to HBCD.


Asunto(s)
Retardadores de Llama , Hidrocarburos Bromados , Bifenilos Polibrominados , Masculino , Animales , Ratones , Retardadores de Llama/toxicidad , Éter , Bioacumulación , Semen , Hidrocarburos Bromados/toxicidad , Bifenilos Polibrominados/toxicidad , Éteres , Éteres de Etila
7.
Nano Lett ; 23(20): 9538-9546, 2023 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-37818838

RESUMEN

Exciton-polaritons are composite quasiparticles that result from the coupling of excitonic transitions and optical modes. They have been extensively studied because of their quantum phenomena and potential applications in unconventional coherent light sources and all-optical control elements. In this work, we report the observation of Bose-Einstein condensation of the upper polariton branch in a transferable WS2 monolayer microcavity. Near the condensation threshold, we observe a nonlinear increase in upper polariton intensity accompanied by a decrease in line width and an increase in temporal coherence, all of which are hallmarks of Bose-Einstein condensation. Simulations show that this condensation occurs within a specific particle density range, depending on the excitonic properties and pumping conditions. The manifestation of upper polariton condensation unlocks new possibilities for studying the condensate competition while linking it to practical realizations in polaritonic lasers. Our findings contribute to the understanding of bosonic systems and offer potential for the development of polaritonic devices.

8.
Cancer Sci ; 114(7): 2951-2960, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37158138

RESUMEN

D-1553 is a small molecule inhibitor selectively targeting KRASG12C and currently in phase II clinical trials. Here, we report the preclinical data demonstrating antitumor activity of D-1553. Potency and specificity of D-1553 in inhibiting GDP-bound KRASG12C mutation were determined by thermal shift assay and KRASG12C -coupled nucleotide exchange assay. In vitro and in vivo antitumor activity of D-1553 alone or in combination with other therapies were evaluated in KRASG12C mutated cancer cells and xenograft models. D-1553 showed selective and potent activity against mutated GDP-bound KRASG12C protein. D-1553 selectively inhibited ERK phosphorylation in NCI-H358 cells harboring KRASG12C mutation. Compared to the KRAS WT and KRASG12D cell lines, D-1553 selectively inhibited cell viability in multiple KRASG12C cell lines, and the potency was slightly superior to sotorasib and adagrasib. In a panel of xenograft tumor models, D-1553, given orally, showed partial or complete tumor regression. The combination of D-1553 with chemotherapy, MEK inhibitor, or SHP2 inhibitor showed stronger potency on tumor growth inhibition or regression compared to D-1553 alone. These findings support the clinical evaluation of D-1553 as an efficacious drug candidate, both as a single agent or in combination, for patients with solid tumors harboring KRASG12C mutation.


Asunto(s)
Neoplasias Pulmonares , Proteínas Proto-Oncogénicas p21(ras) , Animales , Humanos , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Mutación , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Línea Celular Tumoral , Modelos Animales de Enfermedad , Neoplasias Pulmonares/patología
9.
Mol Psychiatry ; 2022 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-35789199

RESUMEN

Social recognition and memory are critical for survival. The hippocampus serves as a central neural substrate underlying the dynamic coding and transmission of social information. Yet the molecular mechanisms regulating social memory integrity in hippocampus remain unelucidated. Here we report unexpected roles of Celsr2, an atypical cadherin, in regulating hippocampal synaptic plasticity and social memory in mice. Celsr2-deficient mice exhibited defective social memory, with rather intact levels of sociability. In vivo fiber photometry recordings disclosed decreased neural activity of dorsal CA1 pyramidal neuron in Celsr2 mutants performing social memory task. Celsr2 deficiency led to selective impairment in NMDAR but not AMPAR-mediated synaptic transmission, and to neuronal hypoactivity in dorsal CA1. Those activity changes were accompanied with exuberant apical dendrites and immaturity of spines of CA1 pyramidal neurons. Strikingly, knockdown of Celsr2 in adult hippocampus recapitulated the behavioral and cellular changes observed in knockout mice. Restoring NMDAR transmission or CA1 neuronal activities rescued social memory deficits. Collectively, these results show a critical role of Celsr2 in orchestrating dorsal hippocampal NMDAR function, dendritic and spine homeostasis, and social memory in adulthood.

10.
J Nanobiotechnology ; 21(1): 141, 2023 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-37120637

RESUMEN

Since the end of 2019, a highly contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has deprived numerous lives worldwide, called COVID-19. Up to date, omicron is the latest variant of concern, and BA.5 is replacing the BA.2 variant to become the main subtype rampaging worldwide. These subtypes harbor an L452R mutation, which increases their transmissibility among vaccinated people. Current methods for identifying SARS-CoV-2 variants are mainly based on polymerase chain reaction (PCR) followed by gene sequencing, making time-consuming processes and expensive instrumentation indispensable. In this study, we developed a rapid and ultrasensitive electrochemical biosensor to achieve the goals of high sensitivity, the ability of distinguishing the variants, and the direct detection of RNAs from viruses simultaneously. We used electrodes made of MXene-AuNP (gold nanoparticle) composites for improved sensitivity and the CRISPR/Cas13a system for high specificity in detecting the single-base L452R mutation in RNAs and clinical samples. Our biosensor will be an excellent supplement to the RT-qPCR method enabling the early diagnosis and quick distinguishment of SARS-CoV-2 Omicron BA.5 and BA.2 variants and more potential variants that might arise in the future.


Asunto(s)
COVID-19 , Nanopartículas del Metal , Humanos , SARS-CoV-2/genética , COVID-19/diagnóstico , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Oro , Mutación , ARN
11.
Clin Exp Pharmacol Physiol ; 50(10): 826-832, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37414099

RESUMEN

Lung adenocarcinoma (LUAD) is a familiar lung cancer with a poor prognosis. This study was meant to determine whether there are differences in survival between younger and older patients with early-stage LUAD because of the rise in the incidence of LUAD in young individuals over the previous few decades. We analysed the clinical, therapeutic and prognostic features of a cohort (2012-2013) of 831 consecutive patients with stage I/II LUAD who underwent curative surgical resection at Shanghai Pulmonary Hospital. Propensity score matching (PSM) was performed for age, sex, tumour size, tumour stage and therapy in a 2:1 ratio between the two groups without taking gender, illness stage at operation or decisive treatment into account. Following PSM analysis to create a 2:1 match for comparison, the final survival study included 163 patients with early-stage LUAD <50 years and 326 patients ≥50 years. Surprisingly, younger patients were overwhelmingly female (65.6%) and never smokers (85.9%). There were no statistical differences between the two groups in terms of the overall survival rate (P = 0.067) or time to advancement (P = 0.76). In conclusion, no significant differences stood out between older and younger patients with stage I/II LUAD regarding overall and disease-free survival rates. Younger patients with early-stage LUAD were more likely to be female and never smokers, which suggests that risk factors other than active smoking may be responsible for lung carcinogenesis in these patients.


Asunto(s)
Adenocarcinoma del Pulmón , Neoplasias Pulmonares , Humanos , Femenino , Masculino , China , Adenocarcinoma del Pulmón/cirugía , Adenocarcinoma del Pulmón/patología , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/cirugía , Pronóstico , Pulmón/patología
12.
Proc Natl Acad Sci U S A ; 117(40): 24634-24639, 2020 10 06.
Artículo en Inglés | MEDLINE | ID: mdl-33020306

RESUMEN

Experimental discovery of ultralarge elastic deformation in nanoscale diamond and machine learning of its electronic and phonon structures have created opportunities to address new scientific questions. Can diamond, with an ultrawide bandgap of 5.6 eV, be completely metallized, solely under mechanical strain without phonon instability, so that its electronic bandgap fully vanishes? Through first-principles calculations, finite-element simulations validated by experiments, and neural network learning, we show here that metallization/demetallization as well as indirect-to-direct bandgap transitions can be achieved reversibly in diamond below threshold strain levels for phonon instability. We identify the pathway to metallization within six-dimensional strain space for different sample geometries. We also explore phonon-instability conditions that promote phase transition to graphite. These findings offer opportunities for tailoring properties of diamond via strain engineering for electronic, photonic, and quantum applications.

13.
J Orthop Sci ; 28(4): 814-820, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35430130

RESUMEN

BACKGROUND: Aspirin has gained increasing use-popularity on account of its multiple benefits. The present study aimed to investigate how a pre-existing long-term aspirin use (L-AU) would affect perioperative complications and postoperative pain in primary total knee arthroplasty (TKA) patients. METHODS: Utilizing the National Inpatient Sample (NIS) database, primary TKAs were divided into L-AU and non-L-AU cohorts. Propensity score matching (PSM) was performed to match the demographics and comorbidities characteristics. Chi-square test and logistic regression analysis were calculated for the risk analysis of perioperative complications and postoperative pain. RESULTS: The popularity of L-AU in primary TKA patients had significantly increased from 1.5% (2005) to 10.5% (2014) in the U.S. Pre-existing L-AU was associated with decreased risks of most perioperative complications (any complication, adjusted odds ratio [aOR]: 0.920), in-hospital mortality (aOR: 0.367), and shortened hospitalization stay (LOS) (aOR: 0.647), etc. However, L-AU was recognized as a risk factor of acute postoperative pain (aOR: 1.466) and slightly higher total cost (aOR: 1.047). CONCLUSIONS: For the first time in the present study, it is found that pre-existing long-term aspirin use is benefic in reducing perioperative complication risk. According to this finding, future research might determine the optimal pre-operational taking time and dose of aspirin use. Consequently, orthopedic surgeons and healthcare providers could provide this valuable advice to specific patients prior to a planned arthroplasty and subsequently gain feasible clinical benefits.


Asunto(s)
Artroplastia de Reemplazo de Rodilla , Humanos , Artroplastia de Reemplazo de Rodilla/efectos adversos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/prevención & control , Complicaciones Posoperatorias/etiología , Dolor Postoperatorio/prevención & control , Hospitalización , Factores de Riesgo , Tiempo de Internación , Estudios Retrospectivos
14.
Oncologist ; 27(3): 163-e213, 2022 03 11.
Artículo en Inglés | MEDLINE | ID: mdl-35274722

RESUMEN

BACKGROUND: D-0316 is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) developed for patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) with EGFR T790M mutation that progressed after prior treatment with the first- or second-generation EGFR-TKI. METHODS: This phase I, open-label, multicenter clinical trial evaluated daily oral D-0316 administration in dose-escalation (25 to 150 mg; 17 patients) and dose-expansion (50, 100 mg; 67 patients) cohorts for safety, tolerability, anti-tumor activity, and pharmacokinetics. RESULTS: D-0316 was well tolerated at daily doses of 25 to 150 mg and the maximum tolerated dose (MTD) was not reached. The most common treatment-related adverse events (AEs) were platelet count decreased, electrocardiogram QT corrected interval prolonged, anemia, rash, low white blood cell count, hypertriglyceridemia, high cholesterol, headache, pruritus, cough, and aspartate transaminase (AST) or alanine transaminase (ALT) increased. Most of AEs were grade 1 or 2. In the 50 and 100 mg group, the overall response rate (ORR) was 33.3% and 45.5%, the disease control rate (DCR) was 86.7% and 93.9%, and the median PFS was 8.3 and 9.6 months, respectively. D-0316 exposure increased in proportion to dose from 25 to 150 mg. The recommended phase II dose (RP2D) was 100 mg. CONCLUSION: D-0316 is safe, tolerable, and effective for patients with locally advanced/metastatic NSCLC with the EGFR T790M mutation who previously received EGFR-TKI. CLINICALTRIALS.GOV IDENTIFIER: NCT03452150.


Asunto(s)
Antineoplásicos , Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Antineoplásicos/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Receptores ErbB , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Mutación , Inhibidores de Proteínas Quinasas/efectos adversos
15.
J Neuroinflammation ; 19(1): 186, 2022 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-35836182

RESUMEN

BACKGROUND: Depression is a recurrent and devastating mental disease that is highly prevalent worldwide. Prolonged exposure to stressful events or a stressful environment is detrimental to mental health. In recent years, an inflammatory hypothesis has been implicated in the pathogenesis of stress-induced depression. However, less attention has been given to the initial phases, when a series of stress reactions and immune responses are initiated. Peripheral CD4+ T cells have been reported as the major contributors to the occurrence of mental disorders. Chronic stress exposure-evoked release of cytokines can promote the differentiation of peripheral CD4+ cells into various phenotypes. Among them, Th17 cells have attracted much attention due to their high pathogenic potential in central nervous system (CNS) diseases. Thus, we intended to determine the crucial role of CD4+ Th17 cells in the development of specific subtypes of depression and unravel the underpinnings of their pathogenetic effect. METHODS: In the present research, a daily 6-h restraint stress paradigm was employed in rats for 28 successive days to mimic the repeated mild and predictable, but inevitable environmental stress in our daily lives. Then, depressive-like symptoms, brain-blood barrier (BBB) permeability, neuroinflammation, and the differentiation and functional changes of CD4+ cells were investigated. RESULTS: We noticed that restrained rats showed significant depressive-like symptoms, concomitant BBB disruption and neuroinflammation in the dorsal striatum (DS). We further observed a time-dependent increase in thymus- and spleen-derived naïve CD4+ T cells, as well as the aggregation of inflammatory Th17 cells in the DS during the period of chronic restraint stress (CRS) exposure. Moreover, increased Th17-derived cytokines in the brain can further impair the BBB integrity, thus allowing more immune cells and cytokines to gain easy access to the CNS. Our findings suggested that, through a complex cascade of events, peripheral immune responses were propagated to the CNS, and gradually exacerbated depressive-like symptoms. Furthermore, inhibiting the differentiation and function of CD4+ T cells with SR1001 in the early stages of CRS exposure ameliorated CRS-induced depressive-like behaviour and the inflammatory response. CONCLUSIONS: Our data demonstrated that inflammatory Th17 cells were pivotal in accelerating the onset and exacerbation of depressive symptoms in CRS-exposed rats. This subtype of CD4+ T cells may be a promising therapeutic target for the early treatment of stress-induced depression.


Asunto(s)
Depresión , Células Th17 , Animales , Encéfalo , Citocinas , Depresión/etiología , Humanos , Ratas , Restricción Física , Células TH1
16.
Phys Rev Lett ; 129(20): 203401, 2022 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-36462004

RESUMEN

The concept of contact interaction is fundamental in various areas of physics. It simplifies physical models by replacing the detailed short-range interaction with a zero-range contact potential that reproduces the same low-energy scattering parameter, i.e., the s-wave scattering length. In this Letter, we generalize this concept to open quantum systems with short-range two-body losses. We show that the short-range two-body losses can be effectively described by a complex scattering length. However, in contrast to closed systems, the dynamics of an open quantum system is governed by the Lindblad master equation the includes a non-Hermitian Hamiltonian as well as an extra recycling term. We thus develop proper methods to regularize both terms in the master equation in the contact (zero-range) limit. We then apply our regularized complex contact interaction to study the dynamic problem of a weakly interacting and dissipating Bose-Einstein condensate. It is found that the physics is greatly enriched because the scattering length is continued from the real axis to the complex plane. For example, we show that a strong dissipation may prevent an attractive Bose-Einstein condensate from collapsing. We further calculate the particle decay in this system to the order of (density)^{3/2} which resembles the celebrated Lee-Huang-Yang correction to the ground state energy of interacting Bose gases [Lee and Yang, Phys. Rev. 105, 1119 (1957)PHRVAO0031-899X10.1103/PhysRev.105.1119; Lee, Huang, and Yang, Phys. Rev. 106, 1135 (1957)PHRVAO0031-899X10.1103/PhysRev.106.1135]. Possible methods for tuning the complex scattering length in cold atomic gas experiments are also discussed.

17.
Mol Psychiatry ; 26(2): 383-395, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33432190

RESUMEN

The GABAB receptor (GABABR) agonist baclofen has been used to treat alcohol and several other substance use disorders (AUD/SUD), yet its underlying neural mechanism remains unclear. The present study aimed to investigate cortical GABABR dynamics following chronic alcohol exposure. Ex vivo brain slice recordings from mice chronically exposed to alcohol revealed a reduction in GABABR-mediated currents, as well as a decrease of GABAB1/2R and G-protein-coupled inwardly rectifying potassium channel 2 (GIRK2) activities in the motor cortex. Moreover, our data indicated that these alterations could be attributed to dephosphorylation at the site of serine 783 (ser-783) in GABAB2 subunit, which regulates the surface expression of GABABR. Furthermore, a human study using paired-pulse-transcranial magnetic stimulation (TMS) analysis further demonstrated a reduced cortical inhibition mediated by GABABR in patients with AUD. Our findings provide the first evidence that chronic alcohol exposure is associated with significantly impaired cortical GABABR function. The ability to promote GABABR signaling may account for the therapeutic efficacy of baclofen in AUD.


Asunto(s)
Canales de Potasio Rectificados Internamente Asociados a la Proteína G , Corteza Motora , Animales , Baclofeno/farmacología , Canales de Potasio Rectificados Internamente Asociados a la Proteína G/metabolismo , Humanos , Ratones , Receptores de GABA-B/metabolismo , Transducción de Señal
18.
Environ Res ; 213: 113747, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35753379

RESUMEN

Predicting the groundwater level of karst aquifers in North China Coalfield is essential for early warning of mine water hazards and regional water resources management. However, the dynamic changes of strata structure and hydrogeological parameters driven by coal mining activity cause challenges to the process-oriented groundwater model. In order to achieve accurate prediction of groundwater level in large mining areas, this study was the first to use the data-driven Nonlinear Autoregressive with External Input (NARX) model to predict the groundwater level of six karst aquifer observation wells in Pingshuo Mining Area. Three variable input scenarios were set up, solely considering meteorological factors, anthropogenic disturbance factors, and considering both meteorological and anthropogenic disturbance factors. The novel partial mutual information (PMI) screening algorithm was adopted to determine optimized input variables in each scenario. The input and feedback delay coefficients of NARX model were determined by using Seasonal-trend Decomposition Procedure Based on Loess (STL) algorithm and auto- and cross-correlation functions. The results showed that PMI algorithm can effectively screen out the optimal input variables for predicting groundwater level, the NSE coefficients of the PMI-NARX models under the three scenarios were 38.81%, 4.26% and 41.46% higher than those of the corresponding control experiments, respectively. In addition, the prediction performance of the PMI-NARX built on the basis of meteorological factors is poor (NSE <0.63). However, in scenarios which solely use anthropogenic disturbance factors and both use meteorological and anthropogenic disturbance factors, the PMI-NARX coupling models exhibit good prediction performance (NSE and R2 are all greater than 0.8). Especially under solely considering anthropogenic disturbance factors scenario, the model still exhibited good prediction accuracy with a negligible number of input variables. The results can provide technical and theoretical support for the prediction of groundwater level in other mining areas.


Asunto(s)
Monitoreo del Ambiente , Agua Subterránea , Monitoreo del Ambiente/métodos , Predicción , Agua Subterránea/química , Minería , Recursos Hídricos
19.
Can J Physiol Pharmacol ; 100(7): 584-593, 2022 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-35413227

RESUMEN

Chemotherapy is one of the most important strategies in the treatment of cancer; however, chemoresistance restricts the effect of chemotherapy. Growing reports suggest that chloride channel-3 (ClC-3) is involved in regulating the sensitivity of multiple chemotherapeutic agents in the chemotherapy of various tumours, while its role in the chemotherapy of cholangiocarcinoma (CCA) is still poorly understood. Herein, we observed that ClC-3 was highly expressed in CCA chemoresistant tissues and CCA cisplatin-resistant cells QBC939/DDP, and the sensitivities of QBC939 and QBC939/DDP cells to cisplatin were all increased after inhibition of ClC-3. Further mechanism exploration revealed that ClC-3 knockdown reduced the level of autophagy. Furthermore, in both QBC939 and QBC939/DDP cells, the autophagy agonist rapamycin eliminated the increased cisplatin sensitivity of ClC-3 knockdown without affecting ClC-3 expression. Collectively, all the findings demonstrate that ClC-3 knockdown increases cisplatin-induced cell death in CCA cells though inhibiting autophagy, regardless of the occurrence of cisplatin resistance. In addition, our results also suggest that targeted inhibition of ClC-3 may be a potential strategy for chemosensitization in CCA chemotherapy.


Asunto(s)
Antineoplásicos , Neoplasias de los Conductos Biliares , Colangiocarcinoma , Antineoplásicos/farmacología , Apoptosis , Autofagia , Neoplasias de los Conductos Biliares/tratamiento farmacológico , Neoplasias de los Conductos Biliares/metabolismo , Conductos Biliares Intrahepáticos/metabolismo , Conductos Biliares Intrahepáticos/patología , Línea Celular Tumoral , Canales de Cloruro , Colangiocarcinoma/tratamiento farmacológico , Colangiocarcinoma/metabolismo , Colangiocarcinoma/patología , Cisplatino/metabolismo , Cisplatino/farmacología , Resistencia a Antineoplásicos , Humanos
20.
Proc Natl Acad Sci U S A ; 116(10): 4117-4122, 2019 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-30770444

RESUMEN

Nanoscale specimens of semiconductor materials as diverse as silicon and diamond are now known to be deformable to large elastic strains without inelastic relaxation. These discoveries harbinger a new age of deep elastic strain engineering of the band structure and device performance of electronic materials. Many possibilities remain to be investigated as to what pure silicon can do as the most versatile electronic material and what an ultrawide bandgap material such as diamond, with many appealing functional figures of merit, can offer after overcoming its present commercial immaturity. Deep elastic strain engineering explores full six-dimensional space of admissible nonlinear elastic strain and its effects on physical properties. Here we present a general method that combines machine learning and ab initio calculations to guide strain engineering whereby material properties and performance could be designed. This method invokes recent advances in the field of artificial intelligence by utilizing a limited amount of ab initio data for the training of a surrogate model, predicting electronic bandgap within an accuracy of 8 meV. Our model is capable of discovering the indirect-to-direct bandgap transition and semiconductor-to-metal transition in silicon by scanning the entire strain space. It is also able to identify the most energy-efficient strain pathways that would transform diamond from an ultrawide-bandgap material to a smaller-bandgap semiconductor. A broad framework is presented to tailor any target figure of merit by recourse to deep elastic strain engineering and machine learning for a variety of applications in microelectronics, optoelectronics, photonics, and energy technologies.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA