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1.
Nature ; 633(8029): 332-337, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39261616

RESUMO

Polar molecules confined in an optical lattice are a versatile platform to explore spin-motion dynamics based on strong, long-range dipolar interactions1,2. The precise tunability3 of Ising and spin-exchange interactions with both microwave and d.c. electric fields makes the molecular system particularly suitable for engineering complex many-body dynamics4-6. Here we used Floquet engineering7 to realize new quantum many-body systems of polar molecules. Using a spin encoded in the two lowest rotational states of ultracold 40K87Rb molecules, we mutually validated XXZ spin models tuned by a Floquet microwave pulse sequence against those tuned by a d.c. electric field through observations of Ramsey contrast dynamics. This validation sets the stage for the realization of Hamiltonians inaccessible with static fields. In particular, we observed two-axis twisting8 mean-field dynamics, generated by a Floquet-engineered XYZ model using itinerant molecules in two-dimensional layers. In the future, Floquet-engineered Hamiltonians could generate entangled states for molecule-based precision measurement9 or could take advantage of the rich molecular structure for quantum simulation of multi-level systems10,11.

2.
Proc Natl Acad Sci U S A ; 118(37)2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34503999

RESUMO

The ancestors of marine mammals once roamed the land and independently committed to an aquatic lifestyle. These macroevolutionary transitions have intrigued scientists for centuries. Here, we generated high-quality genome assemblies of 17 marine mammals (11 cetaceans and six pinnipeds), including eight assemblies at the chromosome level. Incorporating previously published data, we reconstructed the marine mammal phylogeny and population histories and identified numerous idiosyncratic and convergent genomic variations that possibly contributed to the transition from land to water in marine mammal lineages. Genes associated with the formation of blubber (NFIA), vascular development (SEMA3E), and heat production by brown adipose tissue (UCP1) had unique changes that may contribute to marine mammal thermoregulation. We also observed many lineage-specific changes in the marine mammals, including genes associated with deep diving and navigation. Our study advances understanding of the timing, pattern, and molecular changes associated with the evolution of mammalian lineages adapting to aquatic life.


Assuntos
Adaptação Fisiológica , Evolução Molecular , Genoma , Genômica , Mamíferos/fisiologia , Filogenia , Termogênese/genética , Animais , Fatores de Transcrição NFI/genética , Fatores de Transcrição NFI/metabolismo , Seleção Genética , Semaforinas/genética , Semaforinas/metabolismo , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
3.
Phys Rev Lett ; 130(21): 210403, 2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37295118

RESUMO

Understanding the microscopic mechanisms of thermalization in closed quantum systems is among the key challenges in modern quantum many-body physics. We demonstrate a method to probe local thermalization in a large-scale many-body system by exploiting its inherent disorder and use this to uncover the thermalization mechanisms in a three-dimensional, dipolar-interacting spin system with tunable interactions. Utilizing advanced Hamiltonian engineering techniques to explore a range of spin Hamiltonians, we observe a striking change in the characteristic shape and timescale of local correlation decay as we vary the engineered exchange anisotropy. We show that these observations originate from the system's intrinsic many-body dynamics and reveal the signatures of conservation laws within localized clusters of spins, which do not readily manifest using global probes. Our method provides an exquisite lens into the tunable nature of local thermalization dynamics and enables detailed studies of scrambling, thermalization, and hydrodynamics in strongly interacting quantum systems.


Assuntos
Hidrodinâmica , Física , Anisotropia
4.
Small ; 18(13): e2107236, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35166031

RESUMO

Neural stem cells (NSCs) therapy is promising for treating neurodegenerative disorders and neural injuries. However, the limited in vitro expansion, spontaneous differentiation, and decrease in stemness obstruct the acquisition of high quantities of NSCs, restricting the clinical application of cell-based therapies and tissue engineering. This article reports a facile method of promoting NSCs expansion and maintaining stemness using wireless electrical stimulation triggered by piezoelectric nanomaterials. A nanofibrous membrane of poly L-lactic acid (PLLA) is prepared by electrostatic spinning, and the favorable piezoelectric property of PLLA facilitates the freeing of electrons after transformation. These self-powered electric signals generated by PLLA significantly enhance NSCs proliferation. Further, an undifferentiated cellular state is maintained in the NSCs cultured on the surfaces of PLLA nanofibers exposed to ultrasonic vibration. In addition, the neural differentiation potencies and functions of NSCs expanded by piezoelectric-driven localized electricity are not attenuated. Moreover, cell stemness can be maintained by wireless electric stimulation. Taken together, the electronic signals mediated by PLLA nanofibers facilitate NSCs proliferation. This efficient and simple strategy can maintain the stemness of NSCs during proliferation, which is essential for their clinical application, and opens up opportunities for the mass production of NSCs for use in cell therapy.


Assuntos
Nanofibras , Células-Tronco Neurais , Diferenciação Celular , Proliferação de Células , Ácido Láctico , Poliésteres , Engenharia Tecidual , Alicerces Teciduais
5.
Support Care Cancer ; 30(1): 413-421, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34302546

RESUMO

BACKGROUND: Few mortality-scoring models are available for solid tumor patients who are predisposed to develop Escherichia coli-caused bloodstream infection (ECBSI). We aimed to develop a mortality-scoring model by using information from blood culture time to positivity (TTP) and other clinical variables. METHODS: A cohort of solid tumor patients who were admitted to hospital with ECBSI and received empirical antimicrobial therapy was enrolled. Survivors and non-survivors were compared to identify the risk factors of in-hospital mortality. Univariable and multivariable regression analyses were adopted to identify the mortality-associated predictors. Risk scores were assigned by weighting the regression coefficients with corresponding natural logarithm of the odds ratio for each predictor. RESULTS: Solid tumor patients with ECBSI were distributed in the development and validation groups, respectively. Six mortality-associated predictors were identified and included in the scoring model: acute respiratory distress (ARDS), TTP ≤ 8 h, inappropriate antibiotic therapy, blood transfusion, fever ≥ 39 °C, and metastasis. Prognostic scores were categorized into three groups that predicted mortality: low risk (< 10% mortality, 0-1 points), medium risk (10-20% mortality, 2 points), and high risk (> 20% mortality, ≥ 3 points). The TTP-incorporated scoring model showed excellent discrimination and calibration for both groups, with AUC being 0.833 vs 0.844, respectively, and no significant difference in the Hosmer-Lemeshow test (6.709, P = 0.48) and the chi-square test (6.993, P = 0.46). Youden index showed the best cutoff value of ≥ 3 with 76.11% sensitivity and 79.29% specificity. TTP-incorporated scoring model had higher AUC than no TTP-incorporated model (0.837 vs 0.817, P < 0.01). CONCLUSIONS: Our TTP-incorporated scoring model was associated with improving capability in predicting ECBSI-related mortality. It can be a practical tool for clinicians to identify and manage bacteremic solid tumor patients with high risk of mortality.


Assuntos
Neoplasias , Sepse , Escherichia coli , Mortalidade Hospitalar , Humanos , Prognóstico , Estudos Retrospectivos , Fatores de Risco
6.
Int J Mol Sci ; 23(10)2022 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-35628575

RESUMO

The heart is the core organ of the circulatory system. Through the blood circulation system, it has close contact with all tissues and cells in the body. An exosome is an extracellular vesicle enclosed by a phospholipid bilayer. A variety of heart tissue cells can secrete and release exosomes, which transfer RNAs, lipids, proteins, and other biomolecules to adjacent or remote cells, mediate intercellular communication, and regulate the physiological and pathological activities of target cells. Cardiogenic exosomes play an important role in regulating almost all pathological and physiological processes of the heart. In addition, they can also reach distant tissues and organs through the peripheral circulation, exerting profound influence on their functional status. In this paper, the composition and function of cardiogenic exosomes, the factors affecting cardiogenic exosomes and their roles in cardiovascular physiology and pathophysiology are discussed, and the close relationship between cardiovascular system and motor system is innovatively explored from the perspective of exosomes. This study provides a reference for the development and application of exosomes in regenerative medicine and sports health, and also provides a new idea for revealing the close relationship between the heart and other organ systems.


Assuntos
Sistema Cardiovascular , Exossomos , Vesículas Extracelulares , Comunicação Celular , Exossomos/metabolismo , Coração
7.
Water Sci Technol ; 82(5): 967-983, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33031074

RESUMO

An easy-to-use, pollution-free and reusable beaded NiOx(OH)y catalyst for improving hypochlorite oxidation was prepared by impregnating the mixture of persulfate and alkali over alumina and then reduced it with Ni2+. The effects of catalyst preparation conditions and reaction parameters on NaClO conversion rate and Ni2+ dissolution rate were studied. Impregnating the γ-Al2O3 beads in PS/OH- mixed solution with 0.59 M PS and PS/OH- molar ratio of 1.1, and then reducing with 0.8 M Ni2+ solution is the best condition for preparing catalyst. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The best catalytic layer is characterized by high content of chemisorbed oxygen which can be converted into atomic oxygen. The hypochlorite conversion rate increased with the catalyst dosage and reuse times, and decreased with available chlorine, while pH of hypochlorite solution had little effect on the conversion rate. After running stably for 120 h in continuous flow test, the chemisorbed oxygen content in the optimal catalytic layer decreased slightly. Atomic oxygen plays an important role in the decolorization of dye solution by NaClO/NiOx(OH)y system. The oxidant consumption cost of this process is much cheaper than Fenton reagent. The prepared catalyst has great potential in hypochlorite decomposition and wastewater treatment.


Assuntos
Ácido Hipocloroso , Águas Residuárias , Catálise , Oxirredução , Difração de Raios X
8.
Biomed Pharmacother ; 170: 116051, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38154275

RESUMO

Diabetes mellitus is a widespread metabolic disorder with increasing incidence worldwide, posing a considerable threat to human health because of its complications. Therefore, cost-effective antidiabetic drugs with minimal side effects are urgently needed. Dioscin, a naturally occurring compound, helps to reduce the complications of diabetes mellitus by regulating glucose and lipid metabolism, protecting islet ß cells, improving insulin resistance, and inhibiting oxidative stress and inflammatory response. Plant-derived dioscin reduces the risk of toxicity and side effects associated with chemically synthesized drugs. It is a promising option for treating diabetes mellitus because of its preventive and therapeutic effects, which may be attributed to a variety of underlying mechanisms. However, data compiled by current studies are preliminary. Information about the molecular mechanism of dioscin remains limited, and no high-quality human experiments and clinical trials for testing its safety and efficacy have been conducted. As a resource for research in this area, this review is expected to provide a systematic framework for the application of dioscin in the treatment of diabetes mellitus and its complications.


Assuntos
Diabetes Mellitus Tipo 2 , Diosgenina , Ilhotas Pancreáticas , Humanos , Diabetes Mellitus Tipo 2/metabolismo , Hipoglicemiantes/efeitos adversos , Diosgenina/efeitos adversos
9.
J Pharm Anal ; 14(8): 100946, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39258172

RESUMO

Diabetic nephropathy (DN), a severe complication of diabetes, is widely recognized as a primary contributor to end-stage renal disease. Recent studies indicate that the inflammation triggered by Toll-like receptor 4 (TLR4) is of paramount importance in the onset and progression of DN. TLR4 can bind to various ligands, including exogenous ligands such as proteins and polysaccharides from bacteria or viruses, as well as endogenous ligands such as biglycan, fibrinogen, and hyaluronan. In DN, the expression or release of TLR4-related ligands is significantly elevated, resulting in excessive TLR4 activation and increased production of proinflammatory cytokines through downstream signaling pathways. This process is closely associated with the progression of DN. Natural compounds are biologically active products derived from natural sources that have advantages in the treatment of certain diseases. Various types of natural compounds, including alkaloids, flavonoids, polyphenols, terpenoids, glycosides, and polysaccharides, have demonstrated their ability to improve DN by affecting the TLR4 signaling pathway. In this review, we summarize the mechanism of action of TLR4 in DN and the natural compounds that can ameliorate DN by modulating the TLR4 signaling pathway. We specifically highlight the potential of compounds such as curcumin, paclitaxel, berberine, and ursolic acid to inhibit the TLR4 signaling pathway, which provides an important direction of research for the treatment of DN.

10.
Aging Dis ; 14(5): 1555-1582, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37196112

RESUMO

Bone is a tissue that is active throughout the lifespan, and its physiological activities, such as growth, development, absorption, and formation, are always ongoing. All types of stimulation that occur in sports play an important role in regulating the physiological activities of bone. Here, we track the latest research progress locally and abroad, summarize the recent, relevant research results, and systematically summarize the effects of different types of exercise on bone mass, bone strength and bone metabolism. We found that different types of exercise have different effects on bone health due to their unique technical characteristics. Oxidative stress is an important mechanism mediating the exercise regulation of bone homeostasis. Excessive high-intensity exercise does not benefit bone health but induces a high level of oxidative stress in the body, which has a negative impact on bone tissue. Regular moderate exercise can improve the body's antioxidant defense ability, inhibit an excessive oxidative stress response, promote the positive balance of bone metabolism, delay age-related bone loss and deterioration of bone microstructures and have a prevention and treatment effect on osteoporosis caused by many factors. Based on the above findings, we provide evidence for the role of exercise in the prevention and treatment of bone diseases. This study provides a systematic basis for clinicians and professionals to reasonably formulate exercise prescriptions and provides exercise guidance for patients and the general public. This study also provides a reference for follow-up research.

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