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1.
Adv Sci (Weinh) ; 11(30): e2403095, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38867614

RESUMO

Intrauterine growth restriction (IUGR), when a fetus does not grow as expected, is associated with a reduction in hepatic functionality and a higher risk for chronic liver disease in adulthood. Utilizing early developmental plasticity to reverse the outcome of poor fetal programming remains an unexplored area. Focusing on the biochemical profiles of neonates and previous transcriptome findings, piglets from the same fetus are selected as models for studying IUGR. The cellular landscape of the liver is created by scRNA-seq to reveal sex-dependent patterns in IUGR-induced hepatic injury. One week after birth, IUGR piglets experience hypoxic stress. IUGR females exhibit fibroblast-driven T cell conversion into an immune-adapted phenotype, which effectively alleviates inflammation and fosters hepatic regeneration. In contrast, males experience even more severe hepatic injury. Prolonged inflammation due to disrupted lipid metabolism hinders intercellular communication among non-immune cells, which ultimately impairs liver regeneration even into adulthood. Additionally, Apolipoprotein A4 (APOA4) is explored as a novel biomarker by reducing hepatic triglyceride deposition as a protective response against hypoxia in IUGR males. PPARα activation can mitigate hepatic damage and meanwhile restore over-expressed APOA4 to normal in IUGR males. The pioneering study offers valuable insights into the sexually dimorphic responses to hepatic injury during IUGR.


Assuntos
Animais Recém-Nascidos , Modelos Animais de Doenças , Retardo do Crescimento Fetal , Retardo do Crescimento Fetal/metabolismo , Retardo do Crescimento Fetal/genética , Animais , Feminino , Masculino , Suínos , Fígado/metabolismo , Caracteres Sexuais , Gravidez , Hepatopatias/metabolismo , Hepatopatias/genética , Humanos
2.
Environ Res ; 232: 116323, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37271438

RESUMO

The complex structure of the nocturnal boundary layer (NBL) and its impact on air pollution remain poorly understood. In this study, we present in-situ nocturnal flight measurements onboard an unmanned aerial vehicle (UAV) during the wintertime of 2022 at an urban site in Hefei, China. Besides, co-located measurements of radiation intensity and total amount of cloud were conducted. The vertical distribution of temperature, particle number concentration, and relative humidity were obtained to study the structure of NBL and the key factors driving the evolution of the NBL. A multi-layer inversion boundary layer was observed during haze and fog episodes, which affects the vertical diffusion of particles near the surface and leads to a vertical gradient of particle number concentrations. The particle size distribution demonstrates a drastic vertical variation over different sections of the nocturnal boundary layer: homogeneously mixed in the SBL and the RL layer, sharply reduced in the IL. It is found that the temperature and particle number concentration differences between near-surface and at 500 m are highly related to variations of the radiation intensity and the amount of cloud. The decreased cloud cover enhances the surface cooling, creating a shallow NBL with multiple inversion layers, which reinforces the suppression of vertical diffusions and consequently promotes the accumulation of aerosols within the NBL. This reveals an important mechanism for the impact of NBL evolution modulated by cloud radiative effect on the formation of urban haze.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Material Particulado/análise , Dispositivos Aéreos não Tripulados , Monitoramento Ambiental , Poluição do Ar/análise
3.
World J Gastroenterol ; 29(13): 1911-1941, 2023 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-37155531

RESUMO

Colorectal cancer (CRC) is the most common digestive malignancy across the world. Its first-line treatments applied in the routine clinical setting include surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy. However, resistance to therapy has been identified as the major clinical challenge that fails the treatment method, leading to recurrence and distant metastasis. An increasing number of studies have been attempting to explore the underlying mechanisms of the resistance of CRC cells to different therapies, which can be summarized into two aspects: (1) The intrinsic characters and adapted alterations of CRC cells before and during treatment that regulate the drug metabolism, drug transport, drug target, and the activation of signaling pathways; and (2) the suppressive features of the tumor microenvironment (TME). To combat the issue of therapeutic resistance, effective strategies are warranted with a focus on the restoration of CRC cells' sensitivity to specific treatments as well as reprogramming impressive TME into stimulatory conditions. To date, nanotechnology seems promising with scope for improvement of drug mobility, treatment efficacy, and reduction of systemic toxicity. The instinctive advantages offered by nanomaterials enable the diversity of loading cargoes to increase drug concentration and targeting specificity, as well as offer a platform for trying the combination of different treatments to eventually prevent tumor recurrence, metastasis, and reversion of therapy resistance. The present review intends to summarize the known mechanisms of CRC resistance to chemotherapy, radiotherapy, immunotherapy, and targeted therapy, as well as the process of metastasis. We have also emphasized the recent application of nanomaterials in combating therapeutic resistance and preventing metastasis either by combining with other treatment approaches or alone. In summary, nanomedicine is an emerging technology with potential for CRC treatment; hence, efforts should be devoted to targeting cancer cells for the restoration of therapeutic sensitivity as well as reprogramming the TME. It is believed that the combined strategy will be beneficial to achieve synergistic outcomes contributing to control and management of CRC in the future.


Assuntos
Neoplasias Colorretais , Resistencia a Medicamentos Antineoplásicos , Humanos , Nanotecnologia , Sistemas de Liberação de Medicamentos , Imunoterapia , Neoplasias Colorretais/tratamento farmacológico , Microambiente Tumoral
4.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-982348

RESUMO

Leiomyosarcoma of urinary bladder (LMS-UB) is a highly malignant mesenchymal tumor, accounting for less than 0.5% of all bladder malignancies, with a predominant clinical presentation of hematuria. Here we report a case of low-grade LMS-UB. A 44-year-old male patient was admitted to the hospital with urodynia for 2 weeks. The patient's pelvis CT showed a mass on the right part of the bladder. For this reason, he was initially diagnosed with bladder cancer. We performed a robot-assisted laparoscopic enucleation of the bladder tumor and low-grade LMS-UB was diagnosed with the histopathological examination. He underwent 5 cycles of adjuvant chemotherapy after surgery. At 19months postoperative follow-up, the patient had no symptoms, recurrence, or distant metastasis. There is no report on the treatment of LMS-UB with minimally invasive enucleation worldwide. This case provides a new comprehensive treatment method of enucleation combined with adjuvant chemotherapy for early low-grade LMS-UB to reduce complications and improve patients' quality of life after surgery.


Assuntos
Masculino , Humanos , Adulto , Bexiga Urinária/cirurgia , Leiomiossarcoma/secundário , Robótica , Qualidade de Vida , Pelve/patologia , Neoplasias da Bexiga Urinária/patologia , Laparoscopia/métodos
5.
Bioorg Chem ; 128: 106088, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36007479

RESUMO

Four undescribed seco-polyprenylated acylphloroglucinols (seco-PAPs), elodeoidesones A-D (1-4), were characterized from Hypericum elodeoides. Compound 1 represents the 1,6-seco-PAPs with fascinating 5/5 fused ring, while 2-4 possess a 1,2-seco-PAPs skeleton with a five-membered lactone core. Their structures including absolute configurations were established by spectroscopic analyses and quantum chemical computations. A possible biosynthetic pathway of 1-4 from normal PAPs was proposed. All the isolates were investigated for their cytotoxicity against tumor cells. Notably, 1 inhibited the proliferation of MCF-7 cells with the IC50 value of 7.34 µM. Mechanism investigation indicated that 1 induced MCF-7 cells apoptosis by blocking cell cycle at S phase via inducing oxidative DNA damage.


Assuntos
Hypericum , Apoptose , Pontos de Checagem do Ciclo Celular , Humanos , Hypericum/química , Células MCF-7 , Estrutura Molecular , Estresse Oxidativo , Floroglucinol/química
6.
World J Clin Cases ; 10(19): 6548-6554, 2022 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-35979320

RESUMO

BACKGROUND: Laparoscopic cholecystectomy (LC) and laparoscopic common bile duct exploration (LCBDE) has been widely used for management of gallbladder and common bile duct (CBD) stones. Post-operative clip migration is a rare complication of laparoscopic biliary surgery, which can serve as a nidus for stone formation and cause recurrent cholangitis. CASE SUMMARY: A 59-year-old female was admitted to hospital because of fever and acute right upper abdominal pain. She has a history of LC and had a LCBDE surgery 2 mo ago. Physical examination revealed tenderness in the upper quadrant of right abdomen. Computed tomography scan demonstrated a high-density shadow at the distal CBD, which was considered as migrated clips. The speculation was confirmed by endoscopic retrograde cholangiopancreatography examination, and two displaced Hem-o-lok clips were removed with a stone basket. No fever or abdominal pain presented after the operation. In addition to the case report, literature regarding surgical clip migration after laparoscopic biliary surgery was reviewed and discussed. CONCLUSION: Incidence of postoperative clip migration may be reduced by using clips properly and correctly; however, new methods should be explored to occlude cystic duct and vessels. If a patient with a past history of LC or LCBDE presents with features of sepsis and recurrent upper quadrant pain, clip migration must be considered as one of the differential diagnosis.

7.
Sci Total Environ ; 814: 152693, 2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-34974009

RESUMO

The vertical distribution of aerosols has important implications on haze formation as development, which is manifested to some extent by the planetary boundary layer (PBL)-aerosol interactions. Information on the number concentration and size of particles is essential to understand these processes, but studies on vertical profiles of particle number-size distribution are limited. Herein, an unmanned aerial vehicle (UAV) equipped with a custom-built optical particle counter (0.4-10 µm) was used to investigate the vertical profiles of particle number-size distribution in Hefei (China) during January 20-30, 2021. Combining ground-based scanning mobility particle sizer and meteorological data, the pollution accumulation and diffusion mechanisms were analyzed in depth. Results showed that as the pollution episode developed, the vertical distribution of the particle number concentration changed from a flat profile to a sharp vertical gradient. Under polluted conditions, a three-layer structure was clearly evident: uniform distribution in a mixed layer near the ground, a sharply reduced transition layer, and a low number concentration layer in the free atmosphere. Analysis revealed that fundamental to this conversion is that aerosols are highly affected by the PBL dynamics. Concurrent on-UAV and ground-based observations revealed that the ratio of particle numbers in the accumulation mode to that in the Aitken mode was 0.92 ± 0.05 in polluted days, which was almost three times that of clean days. This difference in the ratio of large to small particles suggests that hygroscopic growth of aerosol particles under high humidity conditions played an important role in haze development. Moreover, the sharp vertical gradient of the particle number concentration in the transition layer was identified as an important parameter for characterizing PBL height. The findings in this study highlight the importance of PBL dynamics on the under-studied vertical profiles of particle number-size distribution, especially during heavy pollution episodes.


Assuntos
Poluentes Atmosféricos , Aerossóis/análise , Poluentes Atmosféricos/análise , China , Monitoramento Ambiental , Tamanho da Partícula , Material Particulado/análise
9.
Nanomaterials (Basel) ; 13(1)2022 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-36616070

RESUMO

The development of modern cutting-edge technology relies heavily on the huge success and advancement of nanotechnology, in which nanomaterials and nanostructures provide the indispensable material cornerstone. Owing to their nanoscale dimensions with possible quantum limit, nanomaterials and nanostructures possess a high surface-to-volume ratio, rich surface/interface effects, and distinct physical and chemical properties compared with their bulk counterparts, leading to the remarkably expanded horizons of their applications. Depending on their degree of spatial quantization, low-dimensional nanomaterials are generally categorized into nanoparticles (0D); nanorods, nanowires, and nanobelts (1D); and atomically thin layered materials (2D). This review article provides a comprehensive guide to low-dimensional nanomaterials and nanostructures. It begins with the classification of nanomaterials, followed by an inclusive account of nanofabrication and characterization. Both top-down and bottom-up fabrication approaches are discussed in detail. Next, various significant applications of low-dimensional nanomaterials are discussed, such as photonics, sensors, catalysis, energy storage, diverse coatings, and various bioapplications. This article would serve as a quick and facile guide for scientists and engineers working in the field of nanotechnology and nanomaterials.

10.
Asian J Androl ; 23(6): 627-632, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34100391

RESUMO

Multiple morphological abnormalities of the sperm flagella (MMAF) is a specific type of asthenoteratozoospermia, presenting with multiple morphological anomalies in spermatozoa, such as absent, bent, coiled, short, or irregular caliber flagella. Previous genetic studies revealed pathogenic mutations in genes encoding cilia and flagella-associated proteins (CFAPs; e.g., CFAP43, CFAP44, CFAP65, CFAP69, CFAP70, and CFAP251) responsible for the MMAF phenotype in infertile men from different ethnic groups. However, none of them have been identified in infertile Pakistani males with MMAF. In the current study, two Pakistani families with MMAF patients were recruited. Whole-exome sequencing (WES) of patients and their parents was performed. WES analysis reflected novel biallelic loss-of-function mutations in CFAP43 in both families (Family 1: ENST00000357060.3, p.Arg300Lysfs*22 and p.Thr526Serfs*43 in a compound heterozygous state; Family 2: ENST00000357060.3, p.Thr526Serfs*43 in a homozygous state). Sanger sequencing further confirmed that these mutations were segregated recessively in the families with the MMAF phenotype. Semiquantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) was carried out to detect the effect of the mutation on mRNA of the affected gene. Previous research demonstrated that biallelic loss-of-function mutations in CFAP43 accounted for the majority of all CFAP43-mutant MMAF patients. To the best of our knowledge, this is the first study to report CFAP43 biallelic loss-of-function mutations in a Pakistani population with the MMAF phenotype. This study will help researchers and clinicians to understand the genetic etiology of MMAF better.


Assuntos
Infertilidade Masculina/diagnóstico , Mutação com Perda de Função/genética , Proteínas dos Microtúbulos/genética , Cauda do Espermatozoide/fisiologia , Adolescente , Adulto , Humanos , Infertilidade Masculina/epidemiologia , Masculino , Pessoa de Meia-Idade , Paquistão/epidemiologia
11.
Oxid Med Cell Longev ; 2021: 8874503, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34055199

RESUMO

The marine horseshoe crab (Tachypleus tridentatus) has been considered as food and traditional medicine for many years. Kynurenic acid (KA) was isolated from horseshoe crab in this study for the first time in the world. A previous study in 2018 reported that intraperitoneal administration of KA prevented high-fat diet- (HFD-) induced body weight gain. Now, we investigated the effects of intragastric gavage of KA on HFD mice and found that KA (5 mg/kg/day) inhibited both the body weight gain and the increase of average daily energy intake. KA reduced serum triglyceride and increased serum high-density lipoprotein cholesterol. KA inhibited HFD-induced the increases of serum low-density lipoprotein cholesterol, coronary artery risk index, and atherosclerosis index. KA also suppressed HFD-induced the increase of the ratio of Firmicutes to Bacteroidetes (two dominant gut microbial phyla). KA partially reversed HFD-induced the changes in the composition of gut microbial genera. These overall effects of KA on HFD mice were similar to that of simvastatin (positive control). But the effects of 1.25 mg/kg/day KA on HFD-caused hyperlipidemia were similar to the effects of 5 mg/kg/day simvastatin. The pattern of relative abundance in 40 key genera of gut microbiota from KA group was closer to that from the normal group than that from the simvastatin group. In addition, our in vitro results showed the potential antioxidant activity of KA, which suggests that the improvement effects of KA on HFD mice may be partially associated with antioxidant activity of KA. Our findings demonstrate the potential role of KA as a functional food ingredient for the treatment of obesity and hyperlipidemia as well as the modulation of gut microbiota.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Microbioma Gastrointestinal/efeitos dos fármacos , Hiperlipidemias/tratamento farmacológico , Ácido Cinurênico/uso terapêutico , Obesidade/tratamento farmacológico , Animais , Caranguejos Ferradura , Ácido Cinurênico/farmacologia , Masculino , Camundongos
12.
Bioorg Chem ; 107: 104578, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33383323

RESUMO

Hyperelodione D (1), an undescribed polyprenylated phloroglucinol derivative possessing 6/6/5/5 fused tetracyclic core, together with hyperelodiones E-F (2-3), two unreported analogues bearing 6/5/5 fused tricyclic structure, were isolated from Hypericum elodeoides Choisy. Their planar structures were elucidated by spectroscopic analysis (HRESIMS, 1D and 2D NMR) and their absolute configurations were determined by comparison of experimental and calculated ECD data. The cytotoxicity and retinoid X receptor-α (RXRα) related activities of the isolates were evaluated and the plausible biogenetic pathways of 1-3 were proposed.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Hypericum/química , Floroglucinol/farmacologia , Receptor X Retinoide alfa/antagonistas & inibidores , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Teoria da Densidade Funcional , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Floroglucinol/química , Floroglucinol/isolamento & purificação , Receptor X Retinoide alfa/metabolismo , Relação Estrutura-Atividade
13.
Asian Journal of Andrology ; (6): 627-632, 2021.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-922370

RESUMO

Multiple morphological abnormalities of the sperm flagella (MMAF) is a specific type of asthenoteratozoospermia, presenting with multiple morphological anomalies in spermatozoa, such as absent, bent, coiled, short, or irregular caliber flagella. Previous genetic studies revealed pathogenic mutations in genes encoding cilia and flagella-associated proteins (CFAPs; e.g., CFAP43, CFAP44, CFAP65, CFAP69, CFAP70, and CFAP251) responsible for the MMAF phenotype in infertile men from different ethnic groups. However, none of them have been identified in infertile Pakistani males with MMAF. In the current study, two Pakistani families with MMAF patients were recruited. Whole-exome sequencing (WES) of patients and their parents was performed. WES analysis reflected novel biallelic loss-of-function mutations in CFAP43 in both families (Family 1: ENST00000357060.3, p.Arg300Lysfs*22 and p.Thr526Serfs*43 in a compound heterozygous state; Family 2: ENST00000357060.3, p.Thr526Serfs*43 in a homozygous state). Sanger sequencing further confirmed that these mutations were segregated recessively in the families with the MMAF phenotype. Semiquantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) was carried out to detect the effect of the mutation on mRNA of the affected gene. Previous research demonstrated that biallelic loss-of-function mutations in CFAP43 accounted for the majority of all CFAP43-mutant MMAF patients. To the best of our knowledge, this is the first study to report CFAP43 biallelic loss-of-function mutations in a Pakistani population with the MMAF phenotype. This study will help researchers and clinicians to understand the genetic etiology of MMAF better.


Assuntos
Adolescente , Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Infertilidade Masculina/epidemiologia , Mutação com Perda de Função/genética , Proteínas dos Microtúbulos/genética , Paquistão/epidemiologia , Cauda do Espermatozoide/fisiologia
14.
Chemosphere ; 266: 129148, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33310520

RESUMO

For efficient solar energy harvesting, various engineering strategies to strengthen visible-light responsivity of ZnO photocatalyst is under intensive investigation. In this work, a new ternary C-ZnO/MoS2/mesoporous carbon nanocomposite was successfully prepared by a two-step solution-processed synthesis protocol. The ternary composite exhibits a well-interconnected 3D mesoporous microstructure assembled by carbon nanosheets, which is loaded with quasi 0D ZnO nanoparticles and 2D MoS2 nanosheets. The carbonaceous nanocomposites show enhanced visible-light-driven photocatalytic performance and high photo-corrosion resistance. The incorporation of carbon in the hybrid design has manifold benefits that drastically promotes the photoactivity and photostability. The significant enhancement in photodegradation activity of the hybrid catalysts can be ascribed to a few positive synergistic effects, such as increased surface area and active reaction sites, boosted surface charge utilization efficiency, and band-gap lowering. The high porosity of the distinct microstructure raises the dye adsorption within the material. Tailored interface/surface properties enable more effective mass transport and higher separation efficiency of photo-generated carriers. The modulated electronic structure leads to the narrowing of the ZnO optical bandgap. Meanwhile, coupling with carbon prevents ZnO from photo-corrosion. Our approach highlights the roles of carbon as structure directing and stabilizing agents as well as heteroatom in defect engineering for wide band-gap oxide materials. The rational material design of multivariate mixed-dimensional architecture also provides guiding insight for the advancement of heterogeneous photocatalyst materials with superior performance and durability. The presented engineering strategy would be a promising method for the preparation of nanomaterials supported on 3D carbon network with high porosity and visible-light-driven photocatalytic performance.


Assuntos
Nanocompostos , Óxido de Zinco , Carbono , Luz , Molibdênio
15.
Nanomaterials (Basel) ; 10(10)2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33081190

RESUMO

We report the facile and economic preparation of two-dimensional (2D) and 0D MoSe2 nanostructures based on systematic and non-toxic top-down strategies. We demonstrate the intrinsic peroxidase-like activity of these MoSe2 nanostructures. The catalytic processes begin with facilitated decomposition of H2O2 by using MoSe2 nanostructures as peroxidase mimetics. In turn, a large amount of generated radicals oxidizes 3,3,5,5-tetramethylbenzidine (TMB) to produce a visible color reaction. The enzymatic kinetics of our MoSe2 nanostructures complies with typical Michaelis-Menten theory. Catalytic kinetics study reveals a ping-pong mechanism. Moreover, the primary radical responsible for the oxidation of TMB was identified to be È®2- by active species-trapping experiments. Based on the peroxidase mimicking property, we developed a new colorimetric method for H2O2 detection by using 2D and 0D MoSe2 nanostructures. It is shown that the colorimetric sensing capability of our MoSe2 catalysts is comparable to other 2D materials-based colorimetric platforms. For instance, the linear range of H2O2 detection is between 10 and 250 µM by using 2D functionalized MoSe2 nanosheets as an artificial enzyme. Our work develops a systematic approach to use 2D materials to construct novel enzyme-free mimetic for a visual assay of H2O2, which has promising prospects in medical diagnosis and food security monitoring.

16.
Anal Chem ; 92(16): 11062-11071, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32639743

RESUMO

Aerosol particle hygroscopicity is an important factor in visibility reduction, cloud formation, radiation forcing, and the global climate. The high number concentration of nanoparticles (defined as particles with diameters below 100 nm) means that their hygroscopic growth abilities and potential contributions to the climate and environment are significant. Therefore, a rapid and accurate in situ analysis method for single nanoparticle hygroscopic growth in an atmospheric environment is important to characterize the effects of the particle's physical and chemical properties in this process. In this work, surface plasmon resonance microscopy with azimuthal rotation illumination (SPRM-ARI) is used to observe the hygroscopic growth and water content of single nanoparticles in situ. The hygroscopic growth results of a single-component nanoparticle are well matched with the extended aerosol inorganic model (E-AIM) results, and the proposed method remains reliable even when the relative humidity (RH) exceeds 90%. For a bicomponent nanoparticle (with NaCl as the primary content), the presence of a component without deliquescence phase transitions under increasing humidity conditions causes the measured data to differ from both the Zdanovskii-Stokes-Robinson (ZSR) model and E-AIM predictions in the low RH range. However, because of their complete liquefaction, the growth factor (GF) variation of the bicomponent nanoparticle is close to the model predictions in the high RH range. Finally, based on the positive correlation between particle volume and the gray intensity of SPRM-ARI, GF values can be obtained from the cube root of the gray intensity and the actual water content of single nanoparticles can then be derived.

17.
Adv Sci (Weinh) ; 7(4): 1902863, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32099765

RESUMO

Modulating the temporoparietal junction (TPJ), especially the right counterpart, shows promises in enhancing social cognitive ability. However, it is ambiguous whether the functional lateralization of TPJ determines people's responsiveness to brain stimulation. Here, this issue is investigated with an individual difference approach. Forty-five participants attended three sessions of transcranial direct current stimulation (tDCS) experiments and one neuroimaging session. The results support the symmetric mechanism of left and right TPJ stimulation. First, the left and right TPJ stimulation effect are comparable in the group-level analysis. Second, the individual-level analysis reveals that a less right-lateralized TPJ is associated with a higher level of responsiveness. Participants could be classified into positive responders showing cognitive enhancement and negative responders showing cognitive impairment due to stimulation. The positive responders show weaker connectivity between bilateral TPJ and the medial prefrontal cortex, which mediates the prediction of offline responsiveness by the lateralization and the social-related trait. These findings call for a better characterization and predictive models for whom tDCS should be used for, and highlight the necessity and feasibility of prestimulation screening.

18.
Sensors (Basel) ; 20(3)2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31979192

RESUMO

Micro-Cantilever (MCL) is a thin film structure that is applied for aerosol particle mass sensing. Several modifications to the rectangular MCL (length-to-width ratio, slots at the anchor, serrations at its side edges) are made to deduce the role and influence of the shape of rectangular MCL-based aerosol mass sensors and reduce gas damping. A finite element fluid-structure interaction model was used to investigate the performance of MCL. It is found that (I) the mass sensitivity and quality factor decline with the increasing of length-to-width ratio which alters the resonant frequency of the MCL. The optimum conditions, including the length-to-width ratio (σlw = 5) and resonant frequency (f0 = 540.7 kHz) of the MCL, are obtained with the constant surface area (S = 45,000 µm2) in the frequency domain ranging from 0 to 600 kHz. (II) The slots can enhance the read-out signal and bring a small Q factor drop. (III) The edge serrations on MCL significantly reduce the gas damping. The results provide a reference for the design of aerosol mass sensor, which makes it possible to develop aerosol mass sensor with high frequency, sensitivity, and quality.

19.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-782361

RESUMO

BACKGROUND@#MAVERIC (Mitral Valve Repair Clinical Trial) validates the safety and efficacy of the ARTO system. We here report the first two successful cases of utilizing the ARTO system in patients with symptomatic heart failure (HF) with functional mitral regurgitation (FMR) in Asia.@*METHODS@#Two patients, aged 70 and 63, had severe HF with FMR. Transesophageal echocardiography confirmed that the left ventricular ejection fractions were less than 50% with severe mitral regurgitation (MR) in both patients. Optimizing drug treatment could not mitigate their symptoms. Therefore, we used the ARTO system to repair the mitral valve for these patients on March 5 and 6, 2019, respectively.@*RESULTS@#Mitral valve repairs using the ARTO system were successfully performed under general anaesthesia for these two patients. MR was decreased immediately after the procedures in both patients. The 30-day and 3-month transthoracic echocardiography (TTE) revealed a moderate to severe MR in both patients, and the New York Heart Association (NYHA) scales were also partially improved.@*CONCLUSION@#The first two cases in Asia indicate that the ARTO system is feasible for patients with heart failure with FMR, and the patient selection appears to be crucial.

20.
Nanoscale Res Lett ; 14(1): 271, 2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31399837

RESUMO

Photoluminescent zero-dimensional (0D) quantum dots (QDs) derived from transition metal dichalcogenides, particularly molybdenum disulfide, are presently in the spotlight for their advantageous characteristics for optoelectronics, imaging, and sensors. Nevertheless, up to now, little work has been done to synthesize and explore photoluminescent 0D WS2 QDs, especially by a bottom-up strategy without using usual toxic organic solvents. In this work, we report a facile bottom-up strategy to synthesize high-quality water-soluble tungsten disulfide (WS2) QDs through hydrothermal reaction by using sodium tungstate dihydrate and L-cysteine as W and S sources. Besides, hybrid carbon quantum dots/WS2 QDs were further prepared based on this method. Physicochemical and structural analysis of QD hybrid indicated that the graphitic carbon quantum dots with diameters about 5 nm were held onto WS2 QDs via electrostatic attraction forces. The resultant QDs show good water solubility and stable photoluminescence (PL). The excitation-dependent PL can be attributed to the polydispersity of the synthesized QDs. We found that the PL was stable under continuous irradiation of UV light but can be quenched in the presence of hydrogen peroxide (H2O2). The obtained WS2-based QDs were thus adopted as an electrodeless luminescent probe for H2O2 and for enzymatic sensing of glucose. The hybrid QDs were shown to have a more sensitive LOD in the case of glucose sensing. The Raman study implied that H2O2 causes the partial oxidation of QDs, which may lead to oxidation-induced quenching. Overall, the presented strategy provides a general guideline for facile and low-cost synthesis of other water-soluble layered material QDs and relevant hybrids in large quantity. These WS2-based high-quality water-soluble QDs should be promising for a wide range of applications in optoelectronics, environmental monitoring, medical imaging, and photocatalysis.

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