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2.
Talanta ; 269: 125483, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38042145

RESUMO

High-throughput detection of large-scale samples is the foundation for rapidly accessing massive metabolic data in precision medicine. Machine learning is a powerful tool for uncovering valuable information hidden within massive data. In this work, we achieved the extraction of a single fingerprinting of 1 µL serum within 5 s through a high-throughput detection platform based on functionalized nanoparticles. We quickly obtained over a thousand serum metabolic fingerprintings (SMFs) including those of individuals with Helicobacter pylori (HP) infection. Combining four classical machine learning models and enrichment analysis, we attempted to extract and confirm useful information behind these SMFs. Based on all fingerprint signals, all four models achieved area under the curve (AUC) values of 0.983-1. In particular, orthogonal partial least squares discriminant analysis (OPLS-DA) model obtained value of 1 in both the discovery and validation sets. Fortunately, we identified six significant metabolic features, all of which can greatly contribute to the monitoring of HP infection, with AUC values ranging from 0.906 to 0.985. The combination of these six significant metabolic features can enable the precise monitoring of HP infection in serum, with over 95 % of accuracy, specificity and sensitivity. The OPLS-DA model displayed optimal performance and the corresponding scatter plot visualized the clear distinction between HP and HC. Interestingly, they exhibit a consistent reduction trend compared to healthy controls, prompting us to explore the possible metabolic pathways and potential mechanism. This work demonstrates the potential alliance between high-throughput detection and machine learning, advancing their application in precision medicine.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Humanos , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/metabolismo , Análise dos Mínimos Quadrados
3.
Tour Hosp Res ; 23(2): 213-225, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37520215

RESUMO

Adaptation and recovery are essential for businesses to survive crises and disasters. Drawing on the concepts of business resilience and hospitality service delivery practices, this study explored strategies employed by owners of Vietnamese homestay businesses for adapting to and recovering from the COVID-19 pandemic. Semi-structured interviews with 17 purposefully selected homestay owners were conducted during the pandemic. The thematic analysis of the data revealed three major strategies: adapting operational protocols, modifying products and service offerings, and reinstating the authenticity of the homestay experience. A conceptual model illustrating the transformations in homestay businesses was developed from the findings. As the study particularly revealed that the selected Vietnamese homestay businesses showed a strong capacity for adaptation, we discuss several factors influencing the implementation of adaptation and recovery strategies. This study contributes to the understanding of how micro, small, and medium-sized enterprises can adapt to external shocks and new externalities, and provides practical implications for homestay owners and stakeholders in relation to their post-pandemic business recovery.

4.
ACS Appl Bio Mater ; 6(9): 3395-3405, 2023 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-37133748

RESUMO

The fluorescence of carbon quantum dots (CQDs) has been paid a lot of attention, but its photothermal performance attracts less attention since preparing CQDs with high photothermal conversion efficiency (PCE) is a big challenge. In this work, CQDs with an average size of 2.3 nm and a PCE of up to 59.4% under 650 nm laser irradiation were synthesized by a simple one-pot microwave-assisted solvothermal method using citric acid (CA) and urea (UR) as the precursors and N,N-dimethylformamide as the solvent under an optimized condition (CA/UR = 1/7, 150 °C, and 1 h). The as-prepared CQDs were demonstrated to have unique surface chemical states; i.e., abundant pyrrole, amide, carboxyl, and hydroxyl groups were found on the surfaces of CQDs, which ensure a high PCE. These CQDs were introduced into a thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) to form a CQDs@PNIPAM nanocomposite, and then, a bilayer hydrogel composed of CQDs@PNIPAM and polyacrylamide (PAM) was fabricated. The bilayer hydrogel can be reversibly deformed just by a light switching on/off operation. Based on the excellent photothermal performance, the developed CQDs are expected to be used in photothermal therapy, photoacoustic imaging, and other biomedical fields, and the CQDs@PNIPAM hydrogel nanocomposite is promising to be applied in intelligent device systems as a light-driven smart flexible material.


Assuntos
Pontos Quânticos , Carbono , Hidrogéis , Solventes
5.
BMC Cardiovasc Disord ; 23(1): 60, 2023 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-36732689

RESUMO

BACKGROUND: Both bicuspid aortic valve (BAV) and bovine aortic arch (BA) are considered as markers of thoracic aortic disease (TAD). But the association between them is not yet clear. This study aimed to explore the potential association of BAV and BA with TAD. METHODS: The study involved 449 participants who underwent their first aortic valve replacement in Fuwai Hospital from June 2017 to March 2018. All patients underwent multidetector computed tomography and echocardiography before surgery. The clinical characteristics were recorded to analyze the association between BAV, BA, and TAD. The univariate and multivariate logistic regression analyses were applied to identify the risk factors for TAD. RESULTS: BA accounted for 79.8% of the arch variants and was the most common aortic arch branching variant. BAV was present in 52.6% of the patients with BA and 38.1% of the patients with normal arch (NA). Among the 185 patients in the BAV subgroup, 50 had BA and 135 had NA. No significant differences were found in BAV anatomical phenotype, aortopathy phenotype, and valve function between BA and NA. The multivariate analysis showed that the presence of BAV and male sex were the risk predictors of TAD. BA was not a risk factor for TAD in either univariate or multivariate analysis. CONCLUSIONS: The proportion of BAV in patients with BA was significantly higher than that of NA, but the BAV phenotype and aortopathy were not related to BA. BAV was a risk factor for TAD, whereas BA was not associated with TAD.


Assuntos
Doenças da Aorta , Doença da Válvula Aórtica Bicúspide , Doenças das Valvas Cardíacas , Masculino , Humanos , Doença da Válvula Aórtica Bicúspide/complicações , Aorta Torácica/diagnóstico por imagem , Doenças das Valvas Cardíacas/diagnóstico por imagem , Doenças das Valvas Cardíacas/epidemiologia , Doenças das Valvas Cardíacas/complicações , Valva Aórtica/cirurgia , Doenças da Aorta/complicações
6.
Food Sci Nutr ; 11(2): 1084-1095, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36789058

RESUMO

Evidence on the association of 25-hydroxyvitamin D (25[OH]D) and obesity during the first 5 years of life is limited in China. The objective of this study was to examine the associations between weight, weight for age z score (ZWAZ), weight for length/height z score (ZWHZ), and body mass index for age z score (ZBMI) and 25(OH)D. This was a large population-based cross-sectional multicenter study in which the children aged 0-5 years were recruited from 12 children's healthcare centers by a stratified cluster random-sampling method in 10 cities of the Jiangsu province, China. The 25(OH)D concentration was determined by ELISA. A total of 5289 children were investigated. For 0-71 months children with obesity and nonobesity, the prevalence of vitamin D deficiency was 36.0% and 29.8%, and the 25(OH)D level was 59.8 and 64.0 nmol/L, respectively, and there were all significant difference. Compared with children with nonobesity, children with obesity had higher risk of vitamin D deficiency (OR [95% CI]: 1.33 [1.02, 1.72], p < .05), and had lower 25(OH)D level (ß = -3.84, 95% CI = -7.58, -0.09, p < .05). The results for children aged 24-71 months were similar to those for children aged 0-71 months. However, no significant difference was observed in children aged 0-23 months. Vitamin D deficiency was observed in children with greater adiposity during the first 5 years of life. However, the results mainly came from those in the age group of 2 to 5 years instead of the first 2 years in their lives.

7.
Opt Lett ; 48(2): 411-414, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36638470

RESUMO

The ability to observe quantum coherence and interference is crucial for understanding quantum effects in nonlinear optical spectroscopy and is of fundamental interest in quantum mechanics. Here, we present an experimental study combined with theoretical analysis and numerical simulations to identify the underlying process behind the rotational revivals induced by a pair of time-delayed ultrafast femtosecond laser pulses for air molecules under ambient conditions. Our time-resolved two-dimensional alignment measurements confirm that one-step non-resonant Raman transitions from initial states of mixed molecules play a dominant role, showing a signature of weak-field-induced rotational revivals. Furthermore, we demonstrate that such rotational revival spectra can simultaneously measure the entire pure rotational Raman spectra and observe the quantum interference between two transition pathways from a given initial state. This work provides a powerful tool to observe, control, and identify the rotational dynamics of mixed molecular samples under weak-field excitations.

8.
Spectrochim Acta A Mol Biomol Spectrosc ; 279: 121456, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-35687990

RESUMO

A highly luminescent nitrogen-doped carbon quantum dots (N-CQDs) with a quantum yield of 44% was prepared by a facile hydrothermal synthesis method using citric acid (CA) and ethylenediamine (EDA) with a molar ratio of 1:1 at 200 °C for 5 h. The hypochlorite (ClO-) ions significantly quench the fluorescence of the N-CQDs according to a pseudo-second-order kinetic model. A sensitive and selective quantification method with an excellent linearity in the range of 1.0-10.0 µM was developed to detect ClO- ions based on the fluorescence quenching. The limit of detection (LOD) of 0.43 µM and the limit of quantification (LOQ) of 1.04 µM were achieved, respectively. This approach was successfully applied to detect the residual ClO- ions in local tap water and in swimming pool water. In addition, the developed fluorescence quenching method was also successfully applied in anti-counterfeiting and paper encryption. Both of the applications in real world suggest that the as-prepared N-CQDs is a kind of promising fluorescence probe for rapid detecting ClO- ions in environment fields, and has potential applications in text secrecy fields.


Assuntos
Pontos Quânticos , Carbono , Ácido Hipocloroso , Íons , Luminescência , Nitrogênio , Água
9.
Semin Thorac Cardiovasc Surg ; 34(3): 854-865, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34380080

RESUMO

To compare the outcomes in patients undergoing isolated aortic valve replacement with bicuspid (BAV) vs tricuspid aortic valves (TAV). A total of 1204 consecutive patients (BAV, n = 454; TAV, n = 750) underwent isolated aortic valve replacement (AVR) between 2002 and 2009 at a single institution. Adverse aortic events were defined as the occurrence of aortic dissection or the ascending aorta diameter greater than 50 mm or sudden death during follow-up. Propensity score matching yielded 318 patient pairs. Follow-up was obtained on 1156 patients. The mean length of follow up was 10.4 ± 3.9 years. A total of 155 (13.4%) patients died, and adverse aortic events occurred in 44 (3.8%) patients. After propensity score matching, the 12-year survivals was 85.5% in the BAV group and 89.2% in the TAV group; hazard ratio (HR) 1.6; 95% confidence interval (CI) 1.0-2.5; P = 0.057. The 12-year cumulative incidence of late adverse aortic events was 14.6% in the BAV group and 10.8% in the TAV group; subdistribution hazard ratio (sHR) 1.1; 95% CI 0.6-2.0; P = 0.758. In the isolated aortic regurgitation subgroup, the rate of adverse aortic events was significantly higher in the BAV group than in the TAV group (sHR, 2.1; 95% CI, 1.1-4.0; P = 0.021). The long-term survival after isolated AVR was similar in both BAV and TAV patients. BAV does not increase the adverse aortic events after isolated AVR compared with the TAV.


Assuntos
Estenose da Valva Aórtica , Doença da Válvula Aórtica Bicúspide , Doenças das Valvas Cardíacas , Implante de Prótese de Valva Cardíaca , Aorta/cirurgia , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgia , Doenças das Valvas Cardíacas/complicações , Doenças das Valvas Cardíacas/diagnóstico por imagem , Doenças das Valvas Cardíacas/cirurgia , Implante de Prótese de Valva Cardíaca/efeitos adversos , Humanos , Estudos Retrospectivos , Resultado do Tratamento
10.
Ann Vasc Surg ; 75: 294-300, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33819595

RESUMO

OBJECTIVE: Isolated true subclavian artery aneurysm (SAA) without aberrant subclavian artery or coarctation of descending aorta is a rare peripheral aneurysm. Herein, the experience of our medical center in the treatment of this disease is presented. METHODS: The Division operative log was queried to identify cases of SAA repair between January 2012 and September 2019 that were not associated with coarctation of the aorta or the presence of an aberrant subclavian artery. A total of 22 cases were identified. The characteristics, treatment and clinical outcomes of these cases were assessed. RESULTS: The mean age of patients was 53.5 ± 14.3 years and 14 patients were male (63.6%). Half of the cases were attributed to atherosclerotic degeneration. The clinical symptoms of aneurysms were varied, including asymptomatic, pulsatile mass of supraclavicular fossa, local pain, upper limb embolism, Horner's syndrome and hoarseness. Aneurysms were located on the right in 17 cases, on the left in 3 cases and on both sides in 2 cases. Fifteen (68%) patients underwent an intervention, of which 11 (50%) underwent an open surgical repair, and 4 (18%) underwent endovascular repair. The mean diameter of the aneurysms was 39.5 ± 20.7 mm in the open surgery group, and 24.0 ± 4.7 mm in the endovascular group. The follow-up duration ranged from 2 months to 12 years. One patient died of cardiogenic disease in the untreated group. Patients undergoing open operative repair had 100% patency of the reconstruction. In the endovascular group, one patient had stent occlusion 2 years after the operation. CONCLUSIONS: The most common cause of isolated subclavian aneurysm without aberrant subclavian artery or coarctation of descending aorta is atherosclerosis. The clinical symptoms of aneurysms are varied, and the aneurysms tend to occur on the right side. Based on the anatomical conditions of SAAs, open surgery and endovascular repair can be used for treatment.


Assuntos
Aneurisma/cirurgia , Procedimentos Endovasculares , Artéria Subclávia/cirurgia , Procedimentos Cirúrgicos Vasculares , Adulto , Idoso , Aneurisma/diagnóstico por imagem , Aneurisma/etiologia , Aterosclerose/complicações , Bases de Dados Factuais , Procedimentos Endovasculares/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Artéria Subclávia/diagnóstico por imagem , Fatores de Tempo , Resultado do Tratamento , Procedimentos Cirúrgicos Vasculares/efeitos adversos
11.
J Hum Nutr Diet ; 34(5): 792-806, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33751685

RESUMO

BACKGROUND: To explore the vitamin D status with its demographic and lifestyle factors including dietary, supplementation, and physical activity in 0-5 years old children. METHODS: This was a large population-based cross-sectional multicentre study in which the children were recruited from 12 Children's Health Care Centers by a stratified cluster random-sampling method in 10 cities in Jiangsu Province, China. RESULTS: A total number of 5289 children were investigated. The prevalence of vitamin D deficiency was 30.1%. The concentration of 25 hydroxyvitamin D was 64.0 (46.3-83.0) nmol mL-1 after adjustment for covariates. Children with higher risk of vitamin D deficiency were more likely to be at older age, girls, survey conducted in spring, location in southern Jiangsu province, residence in urban, outdoor activity < 2 h day-1 (all p < 0.05). Moreover, those with lower risk were more likely to be the number of parity ≥ 2 times, vitamin D supplementation from birth to 6 months, the initial time of vitamin D supplementation after birth ≤ 1 months, vitamin D and calcium supplementation in the last 3 months, and dose of vitamin D supplementation > 400 IU day-1 (all p < 0.05). Children with preferences for sweets, meat consumption > 150.0 g day-1 , milk consumption < 250 mL day-1 , time of sleeping < 10 h day-1 had higher risks of vitamin D deficiency. However, these relationships were affected by demographics. CONCLUSIONS: Vitamin D status during the first five years of life was suboptimal and was associated with demographic and lifestyle determinants including milk, meat, sweets, vitamin D and calcium supplementation, sleeping and outdoor activity.


Assuntos
Deficiência de Vitamina D , Vitamina D , Idoso , Criança , Pré-Escolar , Estudos Transversais , Suplementos Nutricionais , Feminino , Humanos , Lactente , Recém-Nascido , Estilo de Vida , Gravidez , Prevalência , Deficiência de Vitamina D/epidemiologia , Vitaminas
12.
J Phys Chem A ; 125(3): 770-776, 2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-33433217

RESUMO

The temporal delayed orthogonal pulse pairs generated by the phase shaping technique are used to study the coherent control of the rotational wave packet dynamics in air. By continuously changing the intrapulse delay of the pump pulse, we measured the corresponding revival signals and obtained a two-dimensional rotational coherent spectrum (2D RCS). An additive property of the rotational dynamics is observed from the revival signals. Moreover, combining with the coherent control model, we find that the 2D RCS can be used to demonstrate the control over the underlying Raman rotational excitation. A beat frequency-dependent oscillation of each rotational transition is obtained. The transition process is revealed from the Fourier transformation about the pump delay. The scheme of this work can be used for further control and detection of the rotational wave packet and can be extended to other molecular dynamic researches.

13.
Interact Cardiovasc Thorac Surg ; 32(2): 306-312, 2021 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-33236083

RESUMO

OBJECTIVES: Aortico-left ventricular tunnel (ALVT) is an extremely rare, abnormal paravalvular communication between the aorta and the left ventricle. Few studies have identified the characteristics and long-term prognosis associated with ALVT. METHODS: The data of 31 patients with ALVT from July 2002 to December 2019 were reviewed. Echocardiography was performed in all patients during the follow-up period. RESULTS: The median age of the patients was 11.5 years. Bicuspid aortic valve and dilatation of the ascending aorta were found in 13 patients, respectively. The aortic orifice in 20 patients showed a close relation to the right sinus and the right-left commissure. Of the 31 patients, 26 were operated on. Mechanical valve replacement was performed in 4 patients and aortic valve repair, in 6 patients. Ascending aortoplasty was performed in 5 patients and aortic replacement was done in 2 patients. One patient died of ventricular fibrillation before the operation. Follow-up of the remaining 30 patients ranged from 1 to 210 months (median 64 months). There were 4 deaths during the follow-up period: 1 had mechanical valve replacement and 3 did not undergo surgical repair. In the 26 patients without aortic valve replacement, 6 had severe regurgitation and 2 had moderate regurgitation. In the 28 patients without replacement of the ascending aorta, 11 had continued dilatation of the ascending aorta, including those who had aortoplasty. CONCLUSIONS: The aortic orifice of ALVT showed an association with the right sinus and the right-left commissure. For patients who did not have surgery, the long-term survival rate remained terrible. Surgical closure should be done as soon as possible after ALVT is diagnosed. The main long-term complications after surgical repair included aortic regurgitation and ascending aortic dilatation.


Assuntos
Túnel Aorticoventricular/patologia , Doença da Válvula Aórtica Bicúspide/patologia , Aorta/cirurgia , Doenças da Aorta/complicações , Valva Aórtica/cirurgia , Insuficiência da Valva Aórtica/cirurgia , Túnel Aorticoventricular/cirurgia , Procedimentos Cirúrgicos Cardíacos , Criança , Ecocardiografia , Feminino , Próteses Valvulares Cardíacas , Ventrículos do Coração/cirurgia , Humanos , Masculino , Estudos Retrospectivos , Procedimentos Cirúrgicos Vasculares/efeitos adversos
14.
Ann Thorac Surg ; 110(2): e129-e130, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32035047

RESUMO

Aortico-left ventricular tunnel (ALVT) is a rare, abnormal, paravalvular communication between the aorta and the left ventricle. ALVT can be associated with a variety of congenital heart diseases, but there are only a few reports of ALVT associated with bicuspid aortic valve (BAV). Herein, we report a case of an 11-year-old boy who successfully underwent aortic valve sparing root replacement for ALVT with BAV and aortic root aneurysm.


Assuntos
Anormalidades Múltiplas/cirurgia , Aorta/anormalidades , Aorta/cirurgia , Valva Aórtica/anormalidades , Doenças das Valvas Cardíacas/cirurgia , Ventrículos do Coração/anormalidades , Ventrículos do Coração/cirurgia , Valva Aórtica/cirurgia , Doença da Válvula Aórtica Bicúspide , Procedimentos Cirúrgicos Cardíacos/métodos , Criança , Doenças das Valvas Cardíacas/complicações , Humanos , Masculino , Tratamentos com Preservação do Órgão , Procedimentos Cirúrgicos Vasculares/métodos
15.
Obes Res Clin Pract ; 14(1): 39-46, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31879074

RESUMO

OBJECTIVE: Data on obesity in relation to bone mineral density(BMD) in infants and preschool children were sparse in China. The objective of this study was to examine the associations between body mass index (BMI) and BMD. SUBJECTS AND METHODS: This was a large population-based multicenter study in which the representative children aged 0-5 years were recruited from 13 Children's Health Care Centers by a stratified cluster random-sampling method in Jiangsu Province, China. BMD was measured by using quantitative ultrasound. The association of BMD with BMI and obesity were evaluated using multiple linear regression and logistic regression analysis taking into account the effects of confounders. The relations between age, weight, height, BMI and BMD were analyzed by using Pearson's correlation and further tested using partial correlation in the additive model. RESULTS: A total of 5,289 children (2786 boys and 2503 girls) were recruited. The BMD was positively linear relation with age, length/height, and was inversely linear relation with BMI (r=0.711, P<0.001; r=0.727, P<0.001; r=-0.318, P<0.001, respectively). The BMD gradually increased when the weight was in the range within 21.2kg, but started to gain slowlyand even decreased when the weight was over 21.2kg. After adjusting for confounders, compared with control group, children with obesityhad higher odds of low BMD (OR 95%CI: 2.73 (1.57, 4.76), P<0.001), the speed of sound (SOS)value in children with obesity was lower 47.45 (ß=-47.45, 95%CI=-85.07, -9.83, P=0.013). CONCLUSIONS: Adiposity was not advantageous for bone mineral density in 0-5-year-old Chinese children.


Assuntos
Adiposidade , Índice de Massa Corporal , Densidade Óssea , Obesidade Infantil/fisiopatologia , Povo Asiático/estatística & dados numéricos , Pré-Escolar , China , Estudos Transversais , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Obesidade Infantil/diagnóstico por imagem , Ultrassonografia
16.
Sensors (Basel) ; 19(12)2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31234289

RESUMO

Trusted positioning data are very important for the fusion of Bluetooth fingerprint positioning (BFP) and Wi-Fi fingerprint positioning (WFP). This paper proposes an adaptive Bluetooth/Wi-Fi fingerprint positioning method based on Gaussian process regression (GPR) and relative distance (RD), which can choose trusted positioning results for fusion. In the offline stage, measurements of the Bluetooth and Wi-Fi received signal strength (RSS) were collected to construct Bluetooth and Wi-Fi fingerprint databases, respectively. Then, fingerprint positioning error prediction models were built with GPR and data from the fingerprint databases. In the online stage, online Bluetooth and Wi-Fi RSS readings were matched with the fingerprint databases to get a Bluetooth fingerprint positioning result (BFPR) and a Wi-Fi fingerprint positioning result (WFPR). Then, with the help of RD and fingerprint positioning error prediction models, whether the positioning results are trusted was determined. The trusted result is selected as the position estimation result when there is only one trusted positioning result among the BFPR and WFPR. The mean is chosen as the position estimation result when both the BFPR and WFPR results are trusted or untrusted. Experimental results showed that the proposed method was better than BFP and WFP, with a mean positioning error of 2.06 m and a root-mean-square error of 1.449 m.

18.
Sensors (Basel) ; 18(8)2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30071642

RESUMO

The human body has a great influence on Wi-Fi signal power. A fixed K value leads to localization errors for the K-nearest neighbor (KNN) algorithm. To address these problems, we present an adaptive weighted KNN positioning method based on an omnidirectional fingerprint database (ODFD) and twice affinity propagation clustering. Firstly, an OFPD is proposed to alleviate body's sheltering impact on signal, which includes position, orientation and the sequence of mean received signal strength (RSS) at each reference point (RP). Secondly, affinity propagation clustering (APC) algorithm is introduced on the offline stage based on the fusion of signal-domain distance and position-domain distance. Finally, adaptive weighted KNN algorithm based on APC is proposed for estimating user's position during online stage. K initial RPs can be obtained by KNN, then they are clustered by APC algorithm based on their position-domain distances. The most probable sub-cluster is reserved by the comparison of RPs' number and signal-domain distance between sub-cluster center and the online RSS readings. The weighted average coordinates in the remaining sub-cluster can be estimated. We have implemented the proposed method with the mean error of 2.2 m, the root mean square error of 1.5 m. Experimental results show that our proposed method outperforms traditional fingerprinting methods.

19.
Bioorg Med Chem ; 25(10): 2800-2810, 2017 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-28389110

RESUMO

A series of novel tetrahydropyrazolopyridone derivatives containing 1,3,4-triazole, triazolylmethyl, and partially saturated heterocyclic moieties as P2 binding element was designed, synthesized, and evaluated in vitro for anticoagulant activity in human and rabbit plasma. All compounds showed moderate to significant potency, and compounds 15b, 15c, 20b, 20c, and 22b were further examined for their inhibitory activity against human FXa in vitro. While compounds 15c and 22b were tested for rat venous thrombosis in vivo. The most promising compound 15c, with an IC50 (FXa) value of 0.14µM and 98% inhibition rate, warranted further investigation as an FXa inhibitor.


Assuntos
Anticoagulantes/síntese química , Desenho de Fármacos , Inibidores do Fator Xa/síntese química , Fator Xa/química , Pirazóis/química , Piridinas/química , Animais , Anticoagulantes/farmacologia , Anticoagulantes/uso terapêutico , Sítios de Ligação , Coagulação Sanguínea/efeitos dos fármacos , Domínio Catalítico , Fator Xa/metabolismo , Inibidores do Fator Xa/farmacologia , Inibidores do Fator Xa/uso terapêutico , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica , Pirazóis/farmacologia , Pirazóis/uso terapêutico , Piridinas/farmacologia , Piridinas/uso terapêutico , Coelhos , Ratos , Relação Estrutura-Atividade , Trombose Venosa/tratamento farmacológico
20.
Onco Targets Ther ; 8: 2635-42, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26396534

RESUMO

BACKGROUND: Osteosarcoma (OS) is the most common primary bone malignancy in children and young adults. MiR-205 has been reported to be negatively correlated with the proliferation and metastasis of many types of cancer, while its effects on the malignant phenotype of OS are unclear. METHODS: Using TaqMan RT polymerase chain reaction analysis, we firstly explored the expression of miR-205 in a panel of OS cell lines. As the expression of miR-205 was significantly decreased in these cell lines, we sought to compensate for its loss by transfection of exogenous miR-205 mimic into MG-63 cells. To further understand the role of miR-205 in OS, we investigated the effects of miR-205 on the proliferation, migration, and invasion of MG-63 cells, and further explored the mechanisms that might be involved. RESULTS: We found that miR-205 was consistently suppressed in OS cells when compared with the normal human osteoblast (NHOst) cell line. Restored expression of miR-205 in the OS (MG-63) cell line significantly inhibited cell proliferation, migration, and invasion. Moreover, bioinformatic prediction suggested that vascular endothelial growth factor A (VEGFA) was the target oncogene for miR-205 in OS cells. Further quantitative RT polymerase chain reaction and Western blot assays identified that overexpression of miR-205 suppressed expression of VEGFA mRNA and protein. Restored expression of VEGFA in MG-63 cells previously treated with miR-205 mimic could partially abolish miR-205-mediated suppression of proliferation and invasion of these cells. CONCLUSION: Collectively, these data suggest that miR-205 might function as a tumor suppressor in OS by, at least partially, targeting VEGFA.

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