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BACKGROUND: We investigated the synergistic effect of stress and habitual salt preference (SP) on blood pressure (BP) in the hospitalized Omicron-infected patients. METHODS: From 15,185 hospitalized Omicron-infected patients who reported having high BP or hypertension, we recruited 662 patients. All patients completed an electronic questionnaire on diet and stress, and were required to complete morning BP monitoring at least three times. RESULTS: The hypertensive group (n = 309) had higher habitual SP (P = 0.015) and COVID-19 related stress (P < 0.001), and had longer hospital stays (7.4 ± 1.5 days vs. 7.2 ± 0.5 days, P = 0.019) compared with controls (n = 353). After adjusting for a wide range of covariates including Omicron epidemic-related stress, habitual SP was found to increase both systolic (4.9 [95% confidence interval (CI), 2.3-7.4] mmHg, P < 0.001) and diastolic (2.1 [95%CI, 0.6-3.6] mmHg, P = 0.006) BP in hypertensive patients, and increase diastolic BP (2.0 [95%CI, 0.2-3.7] mmHg, P = 0.026) in the control group. 31 (8.8%) patients without a history of hypertension were discovered to have elevated BP during hospitalization, and stress was shown to be different in those patients (P < 0.001). In contrast, habitual SP was more common in hypertensive patients with uncontrolled BP, compared with patients with controlled BP (P = 0.002). CONCLUSIONS: Habitual SP and psychosocial stress were associated with higher BP in Omicron-infected patients both with and without hypertension. Nonpharmaceutical intervention including dietary guidance and psychiatric therapy are crucial for BP control during the long COVID-19 period.
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Hipertensão , Síndrome de COVID-19 Pós-Aguda , Cloreto de Sódio na Dieta , Humanos , Pressão Sanguínea , Hipertensão/epidemiologia , Pacientes , Cloreto de Sódio na Dieta/efeitos adversos , Estresse PsicológicoRESUMO
The preservation of cultural heritage assets of all kind is an important task for modern civilizations. This also includes tools and instruments that have been used in the previous decades and centuries. Along with the industrial revolution 200 years ago, mechanical and electrical technologies emerged, together with optical instruments. In the meantime, it is not only museums who showcase these developments, but also companies, universities, and private institutions. Gyroscopes are fascinating instruments with a history dating back 200 years. When J.G.F. Bohnenberger presented his machine to his students in 1810 at the University of Tuebingen, Germany, nobody could have foreseen that this fascinating development would be used for complex orientation and positioning. At the University of Stuttgart, Germany, a collection of 160 exhibits is available and in transition towards their sustainable future. Here, the systems are digitized in 2D, 2.5D, and 3D and are made available for a worldwide community using open access platforms. The technologies being used are computed tomography, computer vision, endoscopy, and photogrammetry. We present a novel workflow for combining voxel representations and colored point clouds, to create digital twins of the physical objects with 0.1 mm precision. This has not yet been investigated and is therefore pioneering work. Advantages and disadvantages are discussed and suggested work for the near future is outlined in this new and challenging field of tech heritage digitization.
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Nonradical-based advanced oxidation processes for pollutant removal have attracted much attention due to their inherent advantages. Herein we report that magnesium oxides (MgO) in CuOMgO/Fe3O4 not only enhanced the catalytic properties but also switched the free radical peroxymonosulfate (PMS)-activated process into the 1O2 based nonradical process. CuOMgO/Fe3O4 catalyst exhibited consistent performance in a wide pH range from 5.0 to 10.0, and the degradation kinetics were not inhibited by the common free radical scavengers, anions, or natural organic matter. Quantitative structure-activity relationships (QSARs) revealed the relationship between the degradation rate constant of 14 substituted phenols and their conventional descriptor variables (i.e., Hammett constants σ, σ-, σ+), half-wave oxidation potential (E1/2), and pKa values. QSARs together with the kinetic isotopic effect (KIE) recognized the electron transfer as the dominant oxidation process. Characterizations and DFT calculation indicated that the incorporated MgO alters the copper sites to highly oxidized metal centers, offering a more suitable platform for PMS to generate metastable copper intermediates. These highly oxidized metals centers of copper played the key role in producing O2â¢- after accepting an electron from another PMS molecule, and finally 1O2 as sole reactive species was generated from the direct oxidation of O2â¢- through thermodynamically feasible reactions.
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Óxido de Magnésio , Peróxidos , Transporte de Elétrons , Cinética , Metais , OxirreduçãoRESUMO
In this paper we demonstrate a novel acoustic wave pressure sensor, based on an aluminum nitride (AlN) piezoelectric thin film. It contains an integrated vacuum cavity, which is micro-fabricated using a cavity silicon-on-insulator (SOI) wafer. This sensor can directly measure the absolute pressure without the help of an external package, and the vacuum cavity gives the sensor a very accurate reference pressure. Meanwhile, the presented pressure sensor is superior to previously reported acoustic wave pressure sensors in terms of the temperature drift. With the carefully designed dual temperature compensation structure, a very low temperature coefficient of frequency (TCF) is achieved. Experimental results show the sensor can measure the absolute pressure in the range of 0 to 0.4 MPa, while the temperature range is from 20 °C to 220 °C with a TCF of -14.4 ppm/°C. Such a TCF is only about half of that of previously reported works.
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Most existing multiview clustering methods require that graph matrices in different views are computed beforehand and that each graph is obtained independently. However, this requirement ignores the correlation between multiple views. In this letter, we tackle the problem of multiview clustering by jointly optimizing the graph matrix to make full use of the data correlation between views. With the interview correlation, a concept factorization-based multiview clustering method is developed for data integration, and the adaptive method correlates the affinity weights of all views. This method differs from nonnegative matrix factorization-based clustering methods in that it can be applicable to data sets containing negative values. Experiments are conducted to demonstrate the effectiveness of the proposed method in comparison with state-of-the-art approaches in terms of accuracy, normalized mutual information, and purity.
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PURPOSE: To test the hypothesis that miR429 expression in renal cancer patients is increased and plays a role in the pathogenesis of the disease. METHODS: Twenty-seven renal cancer patients admitted to our hospital from May 2014 to May 2015 were enrolled as the study group, and 28 non-cancer patients were selected during the same period as the control group. Renal biopsy and serum samples were used to detect miR429 expression levels, and the patient histories were obtained to make relevant associations to clinical outcomes. In addition, the renal cancer cell line SK458 was used for overexpressing or knocking out miR429 in in vitro experiments to observe changes in proliferation and apoptosis rates. RESULTS: The expression levels of miR429 in renal tissues and serum of renal cancer patients were significantly higher compared with control patients (p<0.05). In addition, a correlation was found between the levels of miR429 in the serum of renal cell cancer patients and their clinical outcome after conventional treatment, with patients expressing lower miR429 levels showing better clinical outcomes. Finally, experiments with renal cancer cells revealed that the proliferation of cells overexpressing miR429 was increased and their apoptosis rate was significantly reduced, while the opposite was true in miR429-knockout cells. CONCLUSIONS: It seems that miR429 can inhibit normal apoptosis rates and lead to high proliferation rates. Accordingly, the higher serum miR429 level in renal cancer patients suggests that it plays a role in the pathogenesis of the disease, while the differential miR429 levels according to the patients' clinical outcomes after treatment suggest that miR429 may be useful as a marker for prognosis.
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Carcinoma de Células Renais/genética , MicroRNAs/metabolismo , Adulto , Carcinoma de Células Renais/mortalidade , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Humanos , Masculino , PrognósticoRESUMO
Inspired by gamma-band oscillations and other neurobiological discoveries, neural networks research shifts the emphasis toward temporal coding, which uses explicit times at which spikes occur as an essential dimension in neural representations. We present a feature-linking model (FLM) that uses the timing of spikes to encode information. The first spiking time of FLM is applied to image enhancement, and the processing mechanisms are consistent with the human visual system. The enhancement algorithm achieves boosting the details while preserving the information of the input image. Experiments are conducted to demonstrate the effectiveness of the proposed method. Results show that the proposed method is effective.
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Aumento da Imagem/métodos , Modelos Neurológicos , Redes Neurais de Computação , Ritmo Gama/fisiologia , Humanos , Rede Nervosa/fisiologia , Plasticidade Neuronal/fisiologiaRESUMO
BACKGROUND: Compressed sensing(CS) has been well applied to speed up imaging by exploring image sparsity over predefined basis functions or learnt dictionary. Firstly, the sparse representation is generally obtained in a single transform domain by using wavelet-like methods, which cannot produce optimal sparsity considering sparsity, data adaptivity and computational complexity. Secondly, most state-of-the-art reconstruction models seldom consider composite regularization upon the various structural features of images and transform coefficients sub-bands. Therefore, these two points lead to high sampling rates for reconstructing high-quality images. METHODS: In this paper, an efficient composite sparsity structure is proposed. It learns adaptive dictionary from lowpass uniform discrete curvelet transform sub-band coefficients patches. Consistent with the sparsity structure, a novel composite regularization reconstruction model is developed to improve reconstruction results from highly undersampled k-space data. It is established via minimizing spatial image and lowpass sub-band coefficients total variation regularization, transform sub-bands coefficients l 1 sparse regularization and constraining k-space measurements fidelity. A new augmented Lagrangian method is then introduced to optimize the reconstruction model. It updates representation coefficients of lowpass sub-band coefficients over dictionary, transform sub-bands coefficients and k-space measurements upon the ideas of constrained split augmented Lagrangian shrinkage algorithm. RESULTS: Experimental results on in vivo data show that the proposed method obtains high-quality reconstructed images. The reconstructed images exhibit the least aliasing artifacts and reconstruction error among current CS MRI methods. CONCLUSIONS: The proposed sparsity structure can fit and provide hierarchical sparsity for magnetic resonance images simultaneously, bridging the gap between predefined sparse representation methods and explicit dictionary. The new augmented Lagrangian method provides solutions fully complying to the composite regularization reconstruction model with fast convergence speed.
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Encéfalo/anatomia & histologia , Compressão de Dados/métodos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Análise de Ondaletas , Algoritmos , Humanos , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Chalcone derivatives (E)-3-(4-hydroxy-3-methoxyphenyl)-1-(4-methoxyphenyl) prop-2-en-1-one and (E)-3-(4-hydroxyphenyl)-1-(4-methoxyphenyl) prop-2-en-1-one (Compounds 1 and 2) have been demonstrated to be potent anti-inflammatory agents in our previous study. In light of the relationship of intracellular mechanisms between anti-inflammatories and antioxidants, we further designed and synthesized a series of chalcone derivatives based on 1 and 2, to explore their antioxidant efficacy. The majority of the derivatives exhibited strong protective effects on PC12 (PC12 rat pheochromocytoma) cells exposed to H2O2, and all compounds were nontoxic. A preliminary structure-activity relationship was proposed. Compounds 1 and 1d ((E)-2-methoxy-4-(3-(4-methoxyphenyl)-3-oxoprop-1-en-1-yl) phenyl acrylate) exerted the action in a good dose-dependent manner. Quantitative RT-PCR (qRT-PCR) and western blot analysis showed that 1 and 1d significantly improve the expression of nuclear factor erythroid 2 p45-related factor 2 (Nrf2)-dependent antioxidant genes g-Glutamylcysteine Ligase Catalytic Subunit (GCLC) and heme oxygenase-1 (HO-1) and their corresponding proteins (γ-glutamyl cysteine synthase (γ-GCS) and HO-1) in PC12 cells. Inhibition of GCLC and HO-1 by specific inhibitors, L-buthionine-S-sulfoximine (BSO) and zinc protoporphyrin (ZnPP), respectively, partially reduce the protective effect of 1 and 1d. These data present a series of novel chalcone analogs, especially compounds 1 and 1d, as candidates for treating oxidative stress-related disease by activating the Nrf2-antioxidant responsive element (ARE) pathway.
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Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Chalconas/farmacologia , Neurônios/citologia , Neurônios/efeitos dos fármacos , Animais , Antioxidantes/química , Chalconas/química , Peróxido de Hidrogênio/metabolismo , Neurônios/metabolismo , Células PC12 , RatosRESUMO
The research of plant seeds has always been a focus of agricultural and forestry research, and seed identification is an indispensable part of it. With the continuous application of artificial intelligence technology in the field of agriculture, seed identification through computer vision can effectively promote the development of agricultural and forestry wisdom. Data is the foundation of computer vision, but there is a lack of suitable datasets in the agricultural field. In this paper, a seed dataset named LZUPSD is established. A device based on mobile phones and macro lenses was established to acquire images. The dataset contains 4496 images of 88 different seeds. This dataset can not only be used as data for training deep learning models in the computer field, but also provide important data support for agricultural and forestry research. As an important resource in this field, this dataset plays a positive role in modernizing agriculture and forestry.
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Inteligência Artificial , Sementes , Agricultura , Agricultura FlorestalRESUMO
Goose creates important economic value depending on their enrich nutrients of meat. Our previous study investigates potential candidate genes associated with variations in meat quality between Xianghai Flying (XHF) Goose and Zi Goose through genomic and transcriptome integrated analysis. Screening of 5 differential expression candidate genes related to muscle development identified by the FST, XP-EHH and RNA-seq in breast muscle from various geese. Among them, C1QTNF1 (C1q and TNF related protein 1), a gene of unknown function in goose, which observed mutations in coding sequence regions in sequencing data. Its function was explored after overexpression and knockdown which designed depending on the genetic sequence of the goose, respectively. Results showed that over-expression of C1QTNF1 significantly enhances cell proliferation and viability. In addition, the expression levels of the fusion marker gene Myomaker and the differentiation marker gene MyoD are significantly upregulated in cells. Knock-down C1QTNF1 leads to down regulated Myomaker and MyoD which involved muscle formation. But, the expression level of muscle atrophy marker MuRF is not significantly changed among different transfection groups. Since protein structures and interactions are closely related to their functions, we further analyzed the C1QTNF1 for physicochemical properties, structural predictions, protein interactions and homology. It can be reasonably inferred that C1QTNF1 has a similar effect to collagen, which may affect muscle development. In summary, we first speculate that C1QTNF1 may play an important regulatory role in muscle growth and development and thereby contributes to the further understanding of the genetic mechanisms that underlie meat quality traits of goose.
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Proteínas Aviárias , Proliferação de Células , Gansos , Carne , Animais , Gansos/genética , Gansos/crescimento & desenvolvimento , Gansos/fisiologia , Proteínas Aviárias/genética , Proteínas Aviárias/metabolismo , Carne/análise , Desenvolvimento Muscular , Músculo Esquelético/crescimento & desenvolvimento , Músculo Esquelético/metabolismoRESUMO
OBJECTIVE: To analyze the association between hypertension and tobacco exposure Luoping county of Yunnan province and estimate the direct cost attributable to hypertension . METHODS: Using Probability proportional to size (PPS) sampling method, 5000 rural residents aged over 18 years were selected from 12 townships in Luoping county, Yunnan province in April 2011, from which 4611 subjects completed the survey. Self-designed questionnaires were used to collect general information, smoking status, costs for outpatient consultation, inpatient, treatment, medication, travel, accommodation and extra-nutrition caused by hypertension as well as the information of health-related behavior. Their height, weight, waist circumference, hip circumference and blood pressure were measured. The direct economic burden of hypertension was calculated. Chi-square (χ(2)) test was used to compare gender differences of hypertension prevalence, smoking and passive smoking. And t test was used to compare the differences of direct economic burden of hypertension among different gender, smoking and passive smoking status. Multivariable logistic regression model was used to analyze the influence factors of hypertension. RESULTS: Among the 4611 subjects, the age was (46.90 ± 16.74) years old. Male accounted for 49.8% (2294/4611) and female 50.2% (2317/4611) . The smoking rate was higher in males (75.7% (1736/2294)) than in females(1.6% (38/2317)) (χ(2) = 2669.21, P < 0.01). The passive smoking rate was lower in males (10.0% (230/2294)) than in females (46.2% (1070/2317)) (χ(2) = 744.27, P < 0.05). Non-tobacco exposure rate in males (14.3% (328/1537)) was lower than in females (52.2% (1209/1537)) (χ(2) = 744.37, P < 0.05) . The risk of hypertension in smokers and passive smokers were higher than those without tobacco exposure, OR (95%CI) was 1.41 (1.15-1.71) (P < 0.05) and 1.31 (1.07-1.63) (P < 0.05) respectively. The per capita direct cost of hypertension was (3444.09 ± 3067.83) Yuan. Of this, tobacco exposure (4552.46 ± 3189.05) Yuan was higher than non-tobacco exposure (1907.71 ± 1383.94) Yuan (t = -3.81, P < 0.05) . Moreover, smokers were (6951.71 ± 3422.87) Yuan higher than passive smokers (3128.09 ± 2083.17) Yuan (t = 3.19, P < 0.05) and males (5827.39 ± 3240.50) Yuan were higher than females (2633.03 ± 2569.01) Yuan (t = 3.22, P < 0.05) . The total direct costs of hypertension attributable to smoking and SHS was 41 million and 38 million, respectively. CONCLUSION: Both smoking and SHS had significant impact on prevalence and economic burden of hypertension in Luoping county. Implementing effective strategies to control tobacco exposure is useful to reduce the economic burden of hypertension in the study region.
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Hipertensão/economia , Hipertensão/epidemiologia , Poluição por Fumaça de Tabaco/economia , Adolescente , Adulto , Idoso , China/epidemiologia , Efeitos Psicossociais da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , População Rural , Poluição por Fumaça de Tabaco/estatística & dados numéricos , Adulto JovemRESUMO
Performing transductive learning on graphs with very few labeled data, that is, two or three samples for each category, is challenging due to the lack of supervision. In the existing work, self-supervised learning via a single view model is widely adopted to address the problem. However, recent observation shows multiview representations of an object share the same semantic information in high-level feature space. For each sample, we generate heterogeneous representations and use view-consistency loss to make their representations consistent with each other. Multiview representation also inspires to supervise the pseudolabels generation by the aid of mutual supervision between views. In this article, we thus propose a view-consistent heterogeneous network (VCHN) to learn better representations by aligning view-agnostic semantics. Specifically, VCHN is constructed by constraining the predictions between two views so that the view pairs can supervise each other. To make the best use of cross-view information, we further propose a novel training strategy to generate more reliable pseudolabels, which thus enhances predictions of the VCHN. Extensive experimental results on three benchmark datasets demonstrate that our method achieves superior performance over state-of-the-art methods under very low label rates.
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Sarcomatoid carcinoma of the bladder is rare, and little is known about the prognostic impact of the proportion of sarcomatoid components of the bladder. The present study aimed to assess the prognostic value of the proportion of sarcomatoid components with regard to death and recurrence rates in patients with bladder cancer (BC), and to validate the worse survival results of sarcomatoid carcinomas of the bladder using propensity score matching. Patients with sarcomatoid carcinoma of the bladder who were treated at the Affiliated Hospital of Qingdao University between August 2010 and May 2021 were included in the study. A 1:2 propensity score matching system based on age, sex and pathological T stage was used for sarcomatoid and non-sarcomatoid carcinoma matching. Finally, 114 patients with BC were included. Patients with sarcomatoid carcinoma had worse 5-year cancer-specific survival (CSS) (69.1 vs. 86.9%; log-rank P=0.008) and recurrence-free survival (RFS) (64.1 vs. 83.6%; log-rank P=0.001) rates compared with patients with non-sarcomatoid carcinoma, as had the subgroup with muscle invasion. Multivariate analysis revealed sarcomatoid carcinoma as an independent prognostic factor. Patients with a low proportion of sarcomatoid components (1-50%) had a better prognosis than patients with a high proportion (>50%), and no significant difference was found compared with the non-sarcomatoid group. Overall, a proportion of sarcomatoid components >50% was a predictor of CSS and RFS. Sarcomatoid components markedly increased the risk of death and recurrence in muscle-invasive BC, but not in non-muscle-invasive BC. A higher proportion of sarcomatoid components was significantly associated with poorer survival.
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Identifying promising targets is a critical step in modern drug discovery, with causative genes of diseases that are an important source of successful targets. Previous studies have found that the pathogeneses of various diseases are closely related to the evolutionary events of organisms. Accordingly, evolutionary knowledge can facilitate the prediction of causative genes and further accelerate target identification. With the development of modern biotechnology, massive biomedical data have been accumulated, and knowledge graphs (KGs) have emerged as a powerful approach for integrating and utilizing vast amounts of data. In this study, we constructed an evolution-strengthened knowledge graph (ESKG) and validated applications of ESKG in the identification of causative genes. More importantly, we developed an ESKG-based machine learning model named GraphEvo, which can effectively predict the targetability and the druggability of genes. We further investigated the explainability of the ESKG in druggability prediction by dissecting the evolutionary hallmarks of successful targets. Our study highlights the importance of evolutionary knowledge in biomedical research and demonstrates the potential power of ESKG in promising target identification. The data set of ESKG and the code of GraphEvo can be downloaded from https://github.com/Zhankun-Xiong/GraphEvo.
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The synthesis of a novel D-ring modified docetaxel analogue, in which the oxetane ring is replaced with a γ-lactone, was achieved from 10-deacetylbaccatin III. The key steps of the synthesis include the direct acetylation of the secondary hydroxyl group at C-5 and D-ring opening and intramolecular aldol reaction to form the γ-lactone. In MTT assays, this analogue proved to have equipotent cytotoxicity relative to paclitaxel towards HCT8, HePG2 and BGC23 cancer cell lines, and be more potent than paclitaxel against A549 and A375. It represents the first example of D-ring modified taxoids with significant cytotoxicity.
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Antineoplásicos/farmacologia , Lactonas/química , Taxoides/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Docetaxel , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Conformação Molecular , Estereoisomerismo , Relação Estrutura-Atividade , Taxoides/síntese química , Taxoides/químicaRESUMO
Undifferentiated carcinoma with osteoclast-like giant cells of pancreas (UCOGCP) is a relatively rare tumor worldwide. Its accurate preoperative diagnosis is extremely difficult. Because the mass is usually large and closely related to neighboring structures, it is difficult to locate the tumor and it is often misdiagnosed as pancreatic cancer, neuroendocrine tumor or gastrointestinal stromal tumor. Combining literature to analyze UCOGCP clinical features (including age of onset, prevalent location) and imaging features (including lesion size, mass nature), to explore the value of preoperative CT and MRI in the diagnosis and differential diagnosis of UCOGCP and hope to help clinical diagnosis and treatment.
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OBJECTIVE: Ginsenoside Rd (GSRd) displays a variety of pharmacological effects. However, the underlying role in acute lung injury (ALI) is not clear. In this study, the protective effect of GSRd on lipopolysaccharide (LPS)-induced ALI is investigated to explore the potential mechanisms. METHODS: GSRd-target-ALI-related gene set was constructed. And bioinformatics tools were used to discover the potential mechanism. We observed the survival of subjects for 72âh. In addition, male BALB/c mice were intraperitoneal injected with GSRd (25 and 50âmg/kg) after received one intratracheal instillation of LPS. Inflammatory changes, oxidative stress, and phosphorylation were assessed to study the biological effects. RESULTS: A total of 245 interaction genes were collected. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were enriched in immune-inflammatory system. Among them, PI3K-Akt signaling pathway was the highest-ranked pathway of inflammatory response. In vivo study, it was found that GSRd improved survival in endotoxemic mice and inhibited the major characteristic of ALI. And the p-PI3K and p-Akt expression was significantly decreased by GSRd treatment. CONCLUSION: GSRd could protect mice against LPS-induced ALI effectively by inhibiting the PI3K-Akt signaling pathway.
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Lesão Pulmonar Aguda/tratamento farmacológico , Ginsenosídeos/uso terapêutico , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/mortalidade , Animais , Ginsenosídeos/farmacologia , Lipopolissacarídeos/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Fosfatidilinositol 3-Quinases/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Taxa de SobrevidaRESUMO
STUDY DESIGN: An in vitro biomechanical cadaver study. OBJECTIVES: To evaluate the pull-out strength after 5000 cyclic loading among 4 revision techniques for the loosened iliac screw using corticocancellous bone, longer screw, traditional cement augmentation, and boring cement augmentation. SUMMARY OF BACKGROUND DATA: Iliac screw loosening is still a clinical problem for lumbo-iliac fusion. Although many revision techniques using corticocancellous bone, larger screw, and polymethylmethacrylate (PMMA) augmentation were applied in repairing pedicle screw loosening, their biomechanical effects on the loosened iliac screw remain undetermined. METHODS: Eight fresh human cadaver pelvises with the bone mineral density values ranging from 0.83 to 0.97 g/cm were adopted in this study. After testing the primary screw of 7.5 mm diameter and 70 mm length, 4 revision techniques were sequentially established and tested on the same pelvis as follows: corticocancellous bone, longer screw with 100 mm length, traditional PMMA augmentation, and boring PMMA augmentation. The difference of the boring technique from traditional PMMA augmentation is that PMMA was injected into the screw tract through 3 boring holes of outer cortical shell without removing the screw. On an MTS machine, after 5000 cyclic compressive loading of -200â¼-500 N to the screw head, axial maximum pull-out strengths of the 5 screws were measured and analyzed. RESULTS: The pull-out strengths of the primary screw and 4 revised screws with corticocancellous bone, longer screw and traditional and boring PMMA augmentation were 1167 N, 361 N, 854 N, 1954 N, and 1820 N, respectively. Although longer screw method obtained significantly higher pull-out strength than corticocancellous bone (P<0.05), the revised screws using these 2 techniques exhibited notably lower pull-out strength than the primary screw and 2 PMMA-augmented screws (P<0.05). Either traditional or boring PMMA screw showed obviously higher pull-out strength than the primary screw (P<0.05); however, no significant difference of pull-out strength was detected between the 2 PMMA screws (P>0.05). CONCLUSIONS: Wadding corticocancellous bone and increasing screw length failed to provide sufficient anchoring strength for a loosened iliac screw; however, both traditional and boring PMMA-augmented techniques could effectively increase the fixation strength. On the basis of the viewpoint of minimal invasion, the boring PMMA augmentation may serve as a suitable salvage technique for iliac screw loosening.
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Cimentos Ósseos , Parafusos Ósseos , Ílio/cirurgia , Vértebras Lombares/cirurgia , Falha de Prótese , Idoso , Fenômenos Biomecânicos , Feminino , Humanos , Fixadores Internos , Masculino , Pessoa de Meia-Idade , ReoperaçãoRESUMO
The title compound, C(18)H(21)NO(3), was obtained via a double Mannich condensation reaction of 6-methyl-tetra-hydro-isobenzofuran-1,7(3H,7aH)-dione with formaldehyde and benzyl-amine. The mol-ecule contains three fused rings of which the cyclo-hexa-none and piperidine rings adopt chair conformations and the furan-one ring assumes an envelope conformation. An inter-molecular C-Hâ¯π inter-action is present in the crystal structure.