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1.
Inorg Chem ; 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39360903

RESUMO

Three bis-formylfluorenimide ligands with different bridging groups were designed and synthesized, leading to the successful preparation of six novel alkylaluminum complexes through their reaction with alkylaluminum reagents (AlMe3 or AlEt3). Complexes 1 and 2 were obtained by the reaction of 1,2-propylene-bridged diamine (L1) with AlMe3 or AlEt3. By reacting 1,2-cyclohexylene-bridged diamine (L2) with AlMe3 or AlEt3 to obtain complexes 3 and 4. The above ligands formed a bidentate four-coordinate structure with alkylaluminum, which involved the elimination of one alkyl group as the ligand reacted with alkylaluminum. The complexes 5 and 6 were synthesized through the reaction of 1,2-phenylene-bridged diamine (L3) with AlEt3 in toluene or tetrahydrofuran. Notably, L3 exhibited unique reactivity compared with the other ligands, which formed a tridentate four-coordinated structure when reacting with alkylaluminum. The formation of the tridentate complex resulted from the introduction of a benzimidazole derivative or tetrahydrofuran (THF) molecule along with the elimination of two alkyl groups during its coordination with alkylaluminum. All complexes were characterized via 1H NMR, 13C NMR, and elemental analysis, with structural determination confirmed through X-ray. Furthermore, the catalytic activity in the hydroboration reaction of aldehyde, ketone, and imines was investigated with these complexes as catalysts. Among them, complex 1 demonstrated excellent catalytic performance (up to 99% yield) and broad substrate compatibility (more than 30 substrates) at low catalyst loading (1 mol %) under mild reaction conditions.

2.
Food Res Int ; 195: 114953, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39277260

RESUMO

The deterioration of aroma quality in tea beverages during the shelf life is a significant issue. In this study, sensomics techniques were employed to identify the characteristic factor contributing to aroma degradation in green tea infusion. Samples A (no/faint retort odor) and B (high intensity retort odor) were selected based on their retort-like odor intensity after heat treatment simulating shelf-life conditions. The key odorants were identified through a combination of chemometrics analysis, comparative aromatic extract dilution analysis (cAEDA), detection frequency analysis (DFA), and odor-specific magnitude estimation (OSME). Subsequently, eight odorants, including linalool (892.451 µg/L), (E)-ß-damascenone (5.105 µg/L), phenylacetaldehyde (27.720 µg/L), nonanal (2201.439 µg/L), α-terpineol (7.166 µg/L), geraniol (0.499 µg/L), theaspirane (0.044 µg/L), and 2-hydroxy-5-methylacetophenone (2.973 µg/L), were identified as the key substances contributing to the retort-like odor in sample B. Aroma recombination and omission test further demonstrated that elevated concentrations of nonanal, geraniol, phenylacetaldehyde, and theaspirane might be the primary reasons for the retort odor observed in samples.


Assuntos
Monoterpenos Acíclicos , Odorantes , Chá , Odorantes/análise , Chá/química , Monoterpenos Acíclicos/análise , Armazenamento de Alimentos/métodos , Compostos Orgânicos Voláteis/análise , Cromatografia Gasosa-Espectrometria de Massas , Acetaldeído/análise , Acetaldeído/análogos & derivados , Monoterpenos Cicloexânicos/análise , Terpenos/análise , Cicloexenos/análise , Temperatura Alta , Norisoprenoides
3.
Food Res Int ; 193: 114867, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39160050

RESUMO

The flavor stability of tea beverages during storage has long been a concern. The study aimed to explore the flavor stability of Longjing green tea beverage using accelerated heat treatment trials, addressing the shortage of lengthy storage trials. Sensory evaluations revealed changes in bitterness, umami, overall harmonization, astringency, and ripeness as treatment duration increased. Accompanied by a decrease in L-values, ΔE and an increase in a and b-values. Seventeen non-volatile metabolites and three volatile metabolites were identified differential among samples by metabolomics, with subsequent correlation analysis indicating associations between sensory attributes and specific metabolites. Umami was linked to epigallocatechin 3,5-digallate and alpha-D-glucopyranose, astringency was correlated with ellagic acid and 1-ethyl-1H-pyrrole. Ripeness showed associations with ellagic acid, 6,7-dihydroxycoumarin, heptanal, and benzaldehyde, and overall harmonization was linked to 6,7-dihydroxycoumarin, ß-myrcene, α-terpineol, and heptanal. A series of verification tests confirmed the feasibility of accelerated heat treatment trials to replace traditional storage trials. These results offer valuable insights into unraveling the complex relationship between sensory and chemical profiles of green tea beverages.


Assuntos
Temperatura Alta , Metabolômica , Paladar , Chá , Chá/química , Humanos , Compostos Orgânicos Voláteis/análise , Manipulação de Alimentos/métodos , Masculino , Armazenamento de Alimentos/métodos , Adulto , Ácido Elágico/análise , Feminino
4.
Chemosphere ; 364: 143124, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39168383

RESUMO

Persulfates activation by various nanomaterials has been intensively reported for advanced oxidation processes (AOPs), and substantial progress has been made in understanding the mechanism. However, most of the published articles only present the unnormalized catalytic properties, which generated confusion to compare different catalysts and identify the active sites. Herein, we presented electrochemical surface area (ECSA) as a practical normalized method and confirmed the primary active sites in N-doped graphene. By controlling the aggregation state of graphene sheets to adjust the activity of doped graphite-N species, the active sites for peroxydisulfate (PDS) activation were accurately estimated. In further experiments, specific surface area (SSA, by N2-physisorption and methylene blue adsorption) and ECSA were adopted to conclude the normalized oxidation rate constant and graphitic-N was confirmed as the primary site in nitrogen-doped graphene for the carbocatalyst/PDS system. The normalized results revealed that SSA derived from inert gas on materials could not reflect the true active sites at solid-liquid interface, while ECSA considering the operated solid-liquid situation can be used for accurate estimation of the active sites. Therefore, this study suggests that ECSA integrates the properties of both kinetics and thermodynamics, which can be adopted as a useful methodology for analyzing nano-sized environmental catalysts performance.


Assuntos
Grafite , Oxirredução , Sulfatos , Catálise , Grafite/química , Sulfatos/química , Adsorção , Cinética , Nitrogênio/química , Termodinâmica , Técnicas Eletroquímicas , Nanoestruturas/química , Azul de Metileno/química
5.
Curr Biol ; 34(10): 2077-2084.e3, 2024 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-38663397

RESUMO

Fungal biomineralization plays an important role in the biogeochemical cycling of metals in the environment and has been extensively explored for bioremediation and element biorecovery. However, the cellular and metabolic responses of fungi in the presence of toxic metals during biomineralization and their impact on organic matter transformations are unclear. This is an important question because co-contamination by toxic metals and organic pollutants is a common phenomenon in the natural environment. In this research, the biomineralization process and oxidative stress response of the geoactive soil fungus Aspergillus niger were investigated in the presence of toxic metals (Co, Cu, Mn, and Fe) and the azo dye orange II (AO II). We have found that the co-existence of toxic metals and AO II not only enhanced the fungal biomineralization of toxic metals but also accelerated the removal of AO II. We hypothesize that the fungus and in situ mycogenic biominerals (toxic metal oxalates) constituted a quasi-bioreactor, where the biominerals removed organic pollutants by catalyzing reactive oxygen species (ROS) generation resulting from oxidative stress. We have therefore demonstrated that a fungal/biomineral system can successfully achieve the goal of toxic metal immobilization and organic pollutant decomposition. Such findings inform the potential development of fungal-biomineral hybrid systems for mixed pollutant bioremediation as well as provide further understanding of fungal organic-inorganic pollutant transformations in the environment and their importance in biogeochemical cycles.


Assuntos
Aspergillus niger , Biodegradação Ambiental , Biomineralização , Aspergillus niger/metabolismo , Metais Pesados/metabolismo , Metais Pesados/toxicidade , Poluentes do Solo/metabolismo , Poluentes do Solo/toxicidade , Estresse Oxidativo
6.
J Orthop Surg Res ; 19(1): 162, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429811

RESUMO

OBJECTIVE: The primary aim of the present study was to explore the potential correlation of serum / local CXCL13 expressions and disease severity in non-traumatic osteonecrosis of the femoral head (NT-ONFH). METHODS: In total, NT-ONFH patients (n = 130) together with healthy controls (HCs, n = 130) were included in this investigation. Radiographic progression was evaluated based on the imaging criteria outlined in the ARCO classification system. To assess the diagnostic value of serum CXCL13 in relation to radiographic progression, Receiver operating characteristic (ROC) curve analysis was conducted. Serum CXCL13 levels were quantified utilizing ELISA in all participants. Furthermore, local protein/mRNA expressions of CXCL13 were examined employing immunohistochemistry, western blot, as well as RT-PCR techniques. Clinical severity was appraised using the visual analogue scale (VAS), Harris Hip Score (HHS), and Western Ontario as well as McMaster Universities Osteoarthritis Index (WOMAC). RESULTS: The findings revealed a significant reduction in serum CXCL13 levels among NT-ONFH patients in contrast with HCs. Moreover, both mRNA and protein expressions of CXCL13 were markedly decreased in the necrotic area (NA) than the non-necrotic area (NNA) as well as the healthy femoral head tissues. Additionally, serum CXCL13 levels were substantially lower among patients classified as ARCO stage 4 than those at ARCO stage 3. The concentrations of CXCL13 in stage 3 patients were notably diminished relative to those at ARCO stage 2. Notably, serum CXCL13 levels demonstrated a negative association with ARCO grade. Furthermore, these levels were also inversely linked to VAS scores as well as WOMAC scores while displaying a positive association with HHS scores. The findings of ROC curve suggested that reduced serum CXCL13 levels could be an underlying indicator for ARCO stage. CONCLUSIONS: The reduced levels of either serum CXCL13 or local CXCL13 were intricately linked to disease severity for patients with NT-ONFH.


Assuntos
Necrose da Cabeça do Fêmur , Cabeça do Fêmur , Humanos , Necrose da Cabeça do Fêmur/diagnóstico por imagem , Gravidade do Paciente , Curva ROC , RNA Mensageiro , Quimiocina CXCL13
7.
J Hazard Mater ; 469: 133968, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38452682

RESUMO

Pb2+ is a heavy metal ion pollutant that poses a serious threat to human health and ecosystems. The conventional methods for detecting Pb2+ have several limitations. In this study, we introduce a novel fluorescent probe that enables the detection of Pb2+ in the near-infrared region, free from interference from other common ions. A unique characteristic of this probe is its ability to rapidly and accurately identify Pb2+ through ratiometric measurements accompanied by a large Stokes shift of 201 nm. The limit of detection achieved by probe was remarkably low, surpassing the standards set by the World Health Organization, and outperforming previously reported probes. To the best of our knowledge, this is the first organic small-molecule fluorescent probe with both near-infrared emission and ratiometric properties for the detection of Pb2+. We present a triple-mode sensing platform constructed using a probe that allows for the sensitive and selective recognition of Pb2+ in common food items. Furthermore, we successfully conducted high-quality fluorescence imaging of Pb2+ in various samples from common edible plants, HeLa cells, Caenorhabditis elegans, and mice. Importantly, the probe-Pb2+ complex exhibited tumour-targeting capabilities. Overall, this study presents a novel approach for the development of fluorescent probes for Pb2+ detection.


Assuntos
Corantes Fluorescentes , Chumbo , Humanos , Animais , Camundongos , Células HeLa , Ecossistema
8.
Dalton Trans ; 53(9): 4185-4193, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38323430

RESUMO

Five new alkylaluminum complexes with different pyridinyl-substituted imines or cyclohexyl-substituted imines were synthesized and characterized successfully. The aluminum complex [FlCHNCH(CH3)Py]AlMe2(Py = 2-pyridyl) (1) was obtained by reacting 9-[2-pyridyl-CH(CH3)-NCH]Fl (Fl = fluorenyl) (L1) and equimolar AlMe3. The reactions of 9-(2-pyridyl-NCH)Fl (L2) and 9-[2-N(CH3)2-cyclohexyl-NCH]Fl (L3) with equimolar AlMe3 or AlEt3 afforded other alkylaluminum complexes [FlCHNPy]AlMe2(Py = 2-pyridyl) (2), [FlCHNPy]AlEt2 (Py = 2-pyridyl) (3), [FlCHNCyN(CH3)2]AlMe2 (Cy = 2-cyclohexyl) (4) and [FlCHNCyN(CH3)2]AlEt2 (Cy = 2-cyclohexyl) (5). All these complexes (1-5) were characterized using NMR spectroscopy, elemental analysis, and X-ray crystal structure analysis. The catalytic properties of these new alkylaluminum complexes for the hydrophosphonylation of aldimines were examined. Complex 5 showed the best catalytic performance under mild reaction conditions with a low catalyst loading (1 mol%), and 20 different substituents of aldimines were isolated with more than 90% yields.

9.
PeerJ ; 12: e16701, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38188175

RESUMO

Rapid urbanization has drawn some aquatic environments into the urban texture from the outskirts of cities, and the composition and distribution of plant species in urban wetlands along the urban gradient have changed. Understanding the drivers of these changes will help in the conservation and utilization of urban wetlands. This study investigated the differences in plant diversity and associated influencing factors in three wetlands, Xixi wetland, Tongjian Lake wetland, and Qingshan Lake wetland, which are located in a core area, fringe area, and suburban area of Hangzhou City, respectively. The results showed that a total of 104 families, 254 genera, and 336 species of plants were recorded in the Xixi wetland; 179 species, 150 genera, and 74 families were found in the Qingshan Lake wetland; and 112 species, 96 genera, and 57 families were collected in the Tongjian Lake wetland. The main plant species and flora distribution of the three urban wetlands showed similarities. Indigenous spontaneous vegetation was highest in the Xixi wetland, while cultivated plant species were most abundant in the Tongjian Lake wetland. The introduction of cultivated plants decreased the distance attenuation effect of plant communities, which led to a certain degree of plant diversity convergence among the three wetlands. Eight endangered plants were preserved in the Xixi wetland by planting them in suitable habitats. Ellenberg's indicator values showed that the proportion of heliophilous plants was higher in the Qingshan Lake wetland, while the proportion of thermophilous plants and nitrogen-loving plants in the Tongjian Lake wetland was higher than in the other two wetlands. The importance of artificial interference factors affecting the differences in plant diversity was significantly higher than that of natural environmental factors in urban wetlands. The preservation of spontaneous plants and the introduction of cultivated plants had an importance of 25.73% and 25.38%, respectively. These were the main factors influencing the plant diversity of urban wetlands. The management mode that did not interfere with spontaneous vegetation and confined maintenance to cultivated plants in the Xixi wetland was beneficial for improving wetland plant diversity. Scientific plant reintroduction can also improve wetland plant diversity.


Assuntos
Urbanização , Áreas Alagadas , Humanos , Cidades , China , Lagos
10.
Eur J Med Chem ; 265: 116070, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38134747

RESUMO

Alzheimer's disease (AD) is the most common neurodegenerative disease among the elderly. Contemporary treatments can only relieve symptoms but fail to delay disease progression. Curcumin is a naturally derived compound that has demonstrated significant therapeutic effects in AD treatment. Recently, molecular hybridization has been utilized to combine the pharmacophoric groups present in curcumin with those of other AD drugs, resulting in a series of novel compounds that enhance the therapeutic efficacy through multiple mechanisms. In this review, we firstly provide a concise summary of various pathogenetic hypotheses of AD and the mechanism of action of curcumin in AD, as well as the concept of molecular hybridization. Subsequently, we focus on the recent development of hybrid molecules derived from curcumin, summarizing their structures and pharmacological activities, including cholinesterase inhibitory activity, Aß aggregation inhibitory activity, antioxidant activity, and other activities. The structure-activity relationships were further discussed.


Assuntos
Doença de Alzheimer , Curcumina , Doenças Neurodegenerativas , Humanos , Idoso , Doença de Alzheimer/tratamento farmacológico , Curcumina/farmacologia , Curcumina/uso terapêutico , Curcumina/química , Doenças Neurodegenerativas/tratamento farmacológico , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Relação Estrutura-Atividade , Peptídeos beta-Amiloides
11.
World J Gastrointest Surg ; 15(10): 2351-2356, 2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-37969708

RESUMO

BACKGROUND: Few reports have described living foreign bodies in the human body. The current manuscript demonstrates that computed tomography (CT) is an effective tool for accurate preoperative evaluation of living foreign bodies in clinic. The three-dimensional (3D) reconstruction technology could clearly display anatomical structures, lesions and adjacent organs, improving diagnostic accuracy and guiding the surgical decision-making process. CASE SUMMARY: Herein we describe a 68-year-old man diagnosed with digestive tract perforation and acute peritonitis caused by a foreign body of Monopterus albus. The patient presented to the emergency department with complaints of dull abdominal pain, profuse sweating and a pale complexion during work. A Monopterus albus had entered the patient's body through the anus two hours ago. During hospitalization, the 3D reconstruction technology revealed a perforation of the middle rectum complicated with acute peritonitis and showed a clear and complete Monopterus albus bone morphology in the abdominal and pelvic cavities, with the Monopterus albus biting the mesentery. Laparoscopic examination detected a large (diameter of about 1.5 cm) perforation in the mid-rectum. It could be seen that a Monopterus albus had completely entered the abdominal cavity and had tightly bitten the mesentery of the small intestine. During the operation, the dead Monopterus albus was taken out. CONCLUSION: The current manuscript demonstrates that CT is an effective tool for accurate preoperative evaluation of living foreign bodies in clinic.

12.
Front Immunol ; 14: 1264447, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38022581

RESUMO

"Cytokine storm" is common in critically ill COVID-19 patients, however, mechanisms remain largely unknown. Here, we reported that overexpression of SARS-CoV-2 N protein in diabetic db/db mice significantly increased tubular death and the release of HMGB1, one of the damage-associated molecular patterns (DAMPs), to trigger M1 proinflammatory macrophage activation and production of IL-6, TNF-α, and MCP-1 via a Mincle-Syk/NF-κB-dependent mechanism. This was further confirmed in vitro that overexpression of SARS-CoV-2 N protein caused the release of HMGB1 from injured tubular cells under high AGE conditions, which resulted in M1 macrophage activation and production of proinflammatory cytokines via a Mincle-Syk/NF-κB-dependent mechanism. This was further evidenced by specifically silencing macrophage Mincle to block HMGB1-induced M1 macrophage activation and production of IL-6, TNF-α, and MCP-1 in vitro. Importantly, we also uncovered that treatment with quercetin largely improved SARS-CoV-2 N protein-induced AKI in db/db mice. Mechanistically, we found that quercetin treatment significantly inhibited the release of a DAMP molecule HMGB1 and inactivated M1 pro-inflammatory macrophage while promoting reparative M2 macrophage responses by suppressing Mincle-Syk/NF-κB signaling in vivo and in vitro. In conclusion, SARS-CoV-2 N protein-induced AKI in db/db mice is associated with Mincle-dependent M1 macrophage activation. Inhibition of this pathway may be a mechanism through which quercetin inhibits COVID-19-associated AKI.


Assuntos
Injúria Renal Aguda , COVID-19 , Diabetes Mellitus , Proteína HMGB1 , Camundongos , Animais , Humanos , NF-kappa B/metabolismo , Proteína HMGB1/metabolismo , SARS-CoV-2/metabolismo , Quercetina/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Ativação de Macrófagos , Interleucina-6/metabolismo , COVID-19/metabolismo , Macrófagos/metabolismo , Injúria Renal Aguda/metabolismo , Diabetes Mellitus/metabolismo
13.
BMC Pregnancy Childbirth ; 23(1): 641, 2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37674133

RESUMO

BACKGROUND: Preimplantation genetic testing for aneuploidy (PGT-A) was demonstrated to be superior to conventional IVF in reducing the incidence of miscarriage and abnormal offspring after the first embryo transfer (ET). PGT-A requires several embryo trophectoderm cells, but its negative impacts on embryo development and long-term influence on the health conditions of conceived children have always been a concern. As an alternative, noninvasive PGT-A (niPGT-A) approaches using spent blastocyst culture medium (SBCM) achieved comparable accuracy with PGT-A in several pilot studies. The main objective of this study is to determine whether noninvasive embryo viability testing (niEVT) results in better clinical outcomes than conventional IVF after the first embryo transfer. Furthermore, we further investigated whether niEVT results in higher the live birth rate between women with advanced maternal age (AMA, > 35 years old) and young women or among patients for whom different fertilization protocols are adopted. METHODS: This study will be a double-blind, multicenter, randomized controlled trial (RCT) studying patients of different ages (20-43 years) undergoing different fertilization protocols (in vitro fertilization [IVF] or intracytoplasmic sperm injection [ICSI]). We will enroll 1140 patients at eight reproductive medical centers over 24 months. Eligible patients should have at least two good-quality blastocysts (better than grade 4 CB). The primary outcome will be the live birth rate of the first embryo transfer (ET). Secondary outcomes will include the clinical pregnancy rate, ongoing pregnancy rate, miscarriage rate, cumulative live birth rate, ectopic pregnancy rate, and time to pregnancy. DISCUSSION: In this study, patients who undergo noninvasive embryo viability testing (niEVT) will be compared to women treated by conventional IVF. We will determine the effects on the pregnancy rate, miscarriage rate, and live birth rate and adverse events. We will also investigate whether there is any difference in clinical outcomes among patients with different ages and fertilization protocols (IVF/ICSI). This trial will provide clinical evidence of the effect of noninvasive embryo viability testing on the clinical outcomes of the first embryo transfer. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR) Identifier: ChiCTR2100051408. 9 September 2021.


Assuntos
Aborto Espontâneo , Coeficiente de Natalidade , Criança , Feminino , Gravidez , Humanos , Adulto , Aborto Espontâneo/epidemiologia , Aborto Espontâneo/etiologia , Injeções de Esperma Intracitoplásmicas , Taxa de Gravidez , Aneuploidia , Fertilização in vitro , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Multicêntricos como Assunto
14.
Heliyon ; 9(7): e17996, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37483760

RESUMO

This study was to evaluate whether Intracytoplasmic sperm injection (ICSI) can improve the quality of embryo in patients with poor-quality embryos in the previous In-vitro fertilization (IVF) cycle, which was cancelled before transfer. This was a retrospective cohort study of 178 IVF and 158 ICSI cycles for patients with poor-quality embryos in the previous IVF cycle in the Center for Reproductive Medicine, Women and Children's Hospital of Chongqing Medical University from March 2016 to June 2022. The 2 PN rate, oocyte utilization rate , high-quality embryo rate and clinical pregnancy rate were compared between the two groups. Furthermore, the implantation rate, miscarriage rate and cycle cancelation rate were measured and compared. ICSI resulted in a comparable 2 PN rate, oocyte utilization rate and cycle cancelation rate with IVF. The high-quality embryo rate of ICSI group was significantly higher than that of IVF group (5.56% vs. 2.60%, P < 0.05). Eventually, a total of 239 patients performed embryo transfer. ICSI resulted in a significantly higher clinical pregnancy rate (55.56% vs. 40.98%, P < 0.05) compared with IVF, however, there were no notable differences in miscarriage rate and implantation rate. The present study suggested that ICSI significantly improved the high-quality embryo rate and clinical pregnancy of the patients with poor-quality embryos in the previous IVF cycle. Prospective randomized controlled trials are needed to further verify.

15.
Natl Sci Rev ; 10(4): nwac180, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37089193

RESUMO

The invention of laser cooling has fundamentally influenced the research frontier of atomic physics and quantum physics, and recently an intense focus has been on the studies of cold atom physics in microgravity environments. Herein, we report the results of our laser cooling experiment in TianGong-2 space lab, which operated for 34 consecutive months in orbit. Over such an extended operation time, the quality of laser cooling did not experience any significant decline, while the properties of laser cooling in orbital microgravity were systematically studied. In particular, we demonstrate magneto-optical trapping and polarization-gradient cooling in orbit and carefully examine their performances. A comparison of the in-orbit and on-ground results indicates that a higher cooling efficiency exists in microgravity, including a smaller loss rate during the trapping and cooling process and lower ultimate temperature of laser-cooled atoms. Our progress has laid the technical foundations for future applications of cold atoms in space missions with operation times of the order of years.

16.
J Xray Sci Technol ; 31(4): 713-729, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37092210

RESUMO

BACKGROUND: Chest CT scan is an effective way to detect and diagnose COVID-19 infection. However, features of COVID-19 infection in chest CT images are very complex and heterogeneous, which make segmentation of COVID-19 lesions from CT images quite challenging. OBJECTIVE: To overcome this challenge, this study proposes and tests an end-to-end deep learning method called dual attention fusion UNet (DAF-UNet). METHODS: The proposed DAF-UNet improves the typical UNet into an advanced architecture. The dense-connected convolution is adopted to replace the convolution operation. The mixture of average-pooling and max-pooling acts as the down-sampling in the encoder. Bridge-connected layers, including convolution, batch normalization, and leaky rectified linear unit (leaky ReLU) activation, serve as the skip connections between the encoder and decoder to bridge the semantic gap differences. A multiscale pyramid pooling module acts as the bottleneck to fit the features of COVID-19 lesion with complexity. Furthermore, dual attention feature (DAF) fusion containing channel and position attentions followed the improved UNet to learn the long-dependency contextual features of COVID-19 and further enhance the capacity of the proposed DAF-UNet. The proposed model is first pre-trained on the pseudo label dataset (generated by Inf-Net) containing many samples, then fine-tuned on the standard annotation dataset (provided by the Italian Society of Medical and Interventional Radiology) with high-quality but limited samples to improve performance of COVID-19 lesion segmentation on chest CT images. RESULTS: The Dice coefficient and Sensitivity are 0.778 and 0.798 respectively. The proposed DAF-UNet has higher scores than the popular models (Att-UNet, Dense-UNet, Inf-Net, COPLE-Net) tested using the same dataset as our model. CONCLUSION: The study demonstrates that the proposed DAF-UNet achieves superior performance for precisely segmenting COVID-19 lesions from chest CT scans compared with the state-of-the-art approaches. Thus, the DAF-UNet has promising potential for assisting COVID-19 disease screening and detection.


Assuntos
COVID-19 , Humanos , COVID-19/diagnóstico por imagem , Tomografia Computadorizada por Raios X
18.
Mol Ther ; 31(2): 344-361, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36514292

RESUMO

Increasing evidence shows that SARS-CoV-2 can infect kidneys and cause acute kidney injury (AKI) in critically ill COVID-19 patients. However, mechanisms through which COVID-19 induces AKI are largely unknown, and treatment remains ineffective. Here, we report that kidney-specific overexpressing SARS-CoV-2 N gene can cause AKI, including tubular necrosis and elevated levels of serum creatinine and BUN in 8-week-old diabetic db/db mice, which become worse in those with older age (16 weeks) and underlying diabetic kidney disease (DKD). Treatment with quercetin, a purified product from traditional Chinese medicine (TCM) that shows effective treatment of COVID-19 patients, can significantly inhibit SARS-CoV-2 N protein-induced AKI in diabetic mice with or without underlying DKD. Mechanistically, quercetin can block the binding of SARS-CoV-2 N protein to Smad3, thereby inhibiting Smad3 signaling and Smad3-mediated cell death via the p16-dependent G1 cell-cycle arrest mechanism in vivo and in vitro. In conclusion, SARS-CoV-2 N protein is pathogenic and can cause severe AKI in diabetic mice, particularly in those with older age and pre-existing DKD, via the Smad3-dependent G1 cell-cycle arrest mechanism. Importantly, we identify that quercetin may be an effective TCM compound capable of inhibiting COVID-19 AKI by blocking SARS-CoV-2 N-Smad3-mediated cell death pathway.


Assuntos
Injúria Renal Aguda , COVID-19 , Diabetes Mellitus Experimental , Camundongos , Animais , SARS-CoV-2 , COVID-19/complicações , Quercetina/farmacologia , Diabetes Mellitus Experimental/complicações , Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/patologia , Camundongos Endogâmicos , Pontos de Checagem do Ciclo Celular
19.
J Fluoresc ; 33(2): 731-737, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36512144

RESUMO

In this paper, the novel fluorescence probe XP based on Schiff-base was designed, synthesized and characterized, which could detect Y3+selectively and sensitively. The recognition mechanism of XP toward Y3+ was studied by Job's plot and HRMS. It was investigated that stoichiometric ratio of the probe XP conjugated with Y3+ was 1:2. And the detection limit was calculated as 0.30 µM. In addition, Y3+ was recognized by the test paper made from XP. And the probe XP could detect  Y3+ selectively in Caenorhabditis elegans and the main organs of mice. Thus, XP was considered to have some potential for application in bioimaging.


Assuntos
Corantes Fluorescentes , Ítrio , Camundongos , Animais , Espectrometria de Fluorescência/métodos , Bases de Schiff
20.
Beilstein J Nanotechnol ; 13: 1011-1019, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36225850

RESUMO

To explain the phenomenon of all-optical modulation of quantum cascade laser (QCL), and explore the physics in QCL's gain medium which consists of multiple of dielectric nanostructures with high refractive index under light injection, we modified the 1½-period model to calculate values of electron population and lifetime in each subband which is separated by the nanostructures, optical gain, current and number of photons in the cavity of a mid-infrared QCL modulated with near-infrared optical injection. The results were consistent with an experiment, where the injected light increases the electron population and lifetime, but does not affect the optical gain obviously. Our study can be helpful for optimizing its use and dielectric nanostructure design.

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