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1.
Sci Total Environ ; 698: 134264, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31494416

RESUMO

Phthalate esters (PAEs) have been shown to be ubiquitous in abiotic and biotic environmental compartments; however, information about bioaccumulation behavior and human exposure, both via environmental exposure and the diet, are limited. Herein, we report the concentrations and composition profiles of phthalate esters (PAEs) in biological samples, river water, indoor air, and outdoor air samples collected from an agricultural site in western China. Dibutyl phthalate (DNBP) occupied a relatively high abundance in biological samples, discrepant with the environmental samples in which di-(2-ethylhexyl) phthalate (DEHP) was the dominant congener. Significant correlations (P < 0.05) were observed between the biota and river water samples, indicating that river water heavily influenced PAE accumulation in biological samples. The mean log Bioaccumulation Factors (BAFs) varied from 0.91 to 2.96, which implies that most PAE congeners are not likely to accumulate in organisms. No obvious trends were observed between log octanol-water partition coefficient (KOW) and log BAF values, nor between log octanol-air partition coefficient (KOW) and biota-air accumulation factors (BAAFs). Nevertheless, the calculated log air-water partitioning factors (AWPFs) of diethyl phthalate (DEP), dimethyl phthalate (DMP), and butyl benzyl phthalate (BBP) were similar to predicted values whereas those for diisobutyl phthalate (DIBP), DNBP and DEHP were significantly higher. The estimated daily intakes of PAEs via food ingestion and environmental exposure were 15, 9.4 and 1.2 ng/kg-bw/day in toddlers, children and adults, respectively, laying at the low end of the reported data and well below the reference dose.

2.
Clin Lab ; 65(11)2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31710444

RESUMO

BACKGROUND: The current study aims to explore the clinical value of serum miR-499a-5p in the diagnosis of pancreatic cancer. METHODS: One hundred twenty-four patients with pancreatic cancer (cancer group), 100 patients with benign pancreatic diseases (benign control group), and 100 healthy people (healthy control group) were selected as the observation objects from January 2017 to June 2017. Fasting venous blood samples were collected to detect the levels of CA199 and the relative expression of miR-499a-5p in serum, and to evaluate the diagnostic value for pancreatic cancer. RESULTS: The expression of CA199 in the benign control group and cancer group was significantly higher than that in the healthy control group. However, the expression of miR-499a-5p in the cancer group was significantly higher than that in the benign control group and the healthy control group. But no difference of serum miR-499a-5p level was found in the benign control group and the healthy control group. Receiver operating characteristic (ROC) analysis showed that when used alone, the sensitivity and specificity of miR-499a-5p in the diagnosis of pancreatic cancer were better than that of CA199 (p < 0.05). Moreover, when serum miR-499a-5p was combined with CA199, the diagnostic value for pancreatic cancer increased significantly (p < 0.05). Dual luciferase reporter assay showed that PTEN was a target gene of miR-499a-5p. CONCLUSIONS: In summary, miR-499a-5p is a new, non-invasive biomarker, and the combination of miR-499a-5p and CA199 can improve the diagnostic sensitivity of pancreatic cancer.

3.
Artigo em Inglês | MEDLINE | ID: mdl-31720785

RESUMO

Activation of complement system in central nervous system (CNS) of the patients suffering from prion diseases or animal models infected with prion agents experimentally is reported repeatedly, but which pathways are involved in the complement system during prion infection is not well documented. Here, we evaluated the level of complement factor B (CFB), which is the key factor that triggers alterative pathway (AP) of complement in the brain tissues of scrapie-infected mice with various methodologies. We found that the levels of mRNA and protein of CFB significantly increased in the brain tissues of scrapie-infected mice. Morphologically, the increased CFB-specific signal overlapped with the elevated C3 signal in brain sections of scrapie-infected mice, meanwhile overlapped with damaged neurons and activated microglia, but not with the proliferative astrocytes. Additionally, the level of complement factor P (CFP), the key positive regulator of AP, also increased remarkably in the brain tissues of infected mice. The transcriptional levels of CD55 and CD46, two negative regulators of AP, decreased without significance in brain tissues of scrapie-infected mice at the terminal stage. However, the mRNA and protein levels of CFH, another negative regulator of AP, increased. Through the dynamic analyses of the expressions of CFB, CFP, and CFH in brain sections of 139A-infected mice, which were collected at different time-points during incubation period, illustrated time-dependent increase levels of each factor during the incubation period of scrapie infection. Taken together, our data here demonstrate that the AP of complement cascade is activated in the CNS microenvironment during prion infection.

4.
Genome Biol ; 20(1): 229, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31676016

RESUMO

INTRODUCTION: The ocean microbiome represents one of the largest microbiomes and produces nearly half of the primary energy on the planet through photosynthesis or chemosynthesis. Using recent advances in marine genomics, we explore new applications of oceanic metagenomes for protein structure and function prediction. RESULTS: By processing 1.3 TB of high-quality reads from the Tara Oceans data, we obtain 97 million non-redundant genes. Of the 5721 Pfam families that lack experimental structures, 2801 have at least one member associated with the oceanic metagenomics dataset. We apply C-QUARK, a deep-learning contact-guided ab initio structure prediction pipeline, to model 27 families, where 20 are predicted to have a reliable fold with estimated template modeling score (TM-score) at least 0.5. Detailed analyses reveal that the abundance of microbial genera in the ocean is highly correlated to the frequency of occurrence in the modeled Pfam families, suggesting the significant role of the Tara Oceans genomes in the contact-map prediction and subsequent ab initio folding simulations. Of interesting note, PF15461, which has a majority of members coming from ocean-related bacteria, is identified as an important photosynthetic protein by structure-based function annotations. The pipeline is extended to a set of 417 Pfam families, built on the combination of Tara with other metagenomics datasets, which results in 235 families with an estimated TM-score over 0.5. CONCLUSIONS: These results demonstrate a new avenue to improve the capacity of protein structure and function modeling through marine metagenomics, especially for difficult proteins with few homologous sequences.

5.
Artigo em Inglês | MEDLINE | ID: mdl-31608496

RESUMO

Diabetic retinopathy (DR) is one of the diabetic complications associated with hyperglycaemia-mediated oxidative stress. Activin receptor-like kinase 7 (ALK7) has been proven to be a potential therapeutic approach for diabetic cardiomyopathy, which is another diabetic complication. However, the role of ALK7 in DR remains unclear. In the current study, ALK7 was found to be up-regulated in clinical samples from DR patients and high glucose (HG)-induced human retinal pigment epithelial cells (ARPE-19). In vitro studies demonstrated that knockdown of ALK7 in ARPE-19 cells through transfection with siRNA-ALK7 (si-ALK7) improved cell viability in HG-induced ARPE-19 cells. Knockdown of ALK7 suppressed HG-induced reactive oxygen species (ROS) production, as well elevating the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) in ARPE-19 cells. The number of apoptotic cells was significantly decreased after transfection with si-ALK7. ALK7 knockdown also caused a significant decrease in bax expression and an increase in bcl-2 expression in HG-induced ARPE-19 cells. In addition, ALK7 knockdown resulted in remarkable increase in the expressions of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase-1 (HO-1) in ARPE-19 cells in response to HG induction. Taken together, knockdown of ALK7 protected ARPE-19 cells from HG-induced oxidative injury, which might be mediated by the activation of the Nrf2/HO-1 signalling pathway.

6.
Artigo em Inglês | MEDLINE | ID: mdl-31597487

RESUMO

Introduction: Microwaves (MWs) quickly deliver relatively high temperatures into tumors and cover a large ablation zone. We present a research protocol for using water-cooled double-needle MW ablation arrays for tumor ablation here. Material and methods: Our research program includes computer modeling, tissue-mimicking phantom experiments, and in vitro swine liver experiments. The computer modeling is based on the finite element method (FEM) to evaluate ablation temperature distributions. In tissue-mimicking phantom and in vitro swine liver ablation experiments, the performances of the new device and the single-needle MW device currently used in clinical practice are compared. Results: FEM shows that the maximum transverse ablation diameter (MTAD) is 4.2 cm at 100 W output and 300 s (assessed at the 50 °C isotherm). In the tissue-mimicking phantom, the MTDA is 2.6 cm at 50 W and 300 s in single-needle MW ablation, and 4 cm in double needle MW ablation array. In in vitro swine liver experiments, the MTAD is 2.820 ± 0.127 cm at 100 W and 300 s in single-needle MW ablation, and 3.847 ± 0.103 cm in MW ablation array. Conclusion: A new type of water-cooled MW ablation array is designed and tested, and has potential advantages over currently used devices.

7.
Toxicol In Vitro ; : 104471, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31628011

RESUMO

For the past five years, Dr. Daniel Acosta has served as the Deputy Director of Research at the National Center for Toxicological Research (NCTR), a principle research laboratory of the U.S. Food and Drug Administration (FDA). Over his career at NCTR, Dr. Acosta has had a major impact on developing and promoting the use of in vitro assays in regulatory toxicity and product safety assessments. As Dr. Acosta nears his retirement we have dedicated this paper to his many accomplishments at the NCTR. Described within this paper are some of the in vitro studies that have been conducted under Dr. Acosta's leadership. These studies include toxicological assessments involving developmental effects, and the development and application of in vitro reproductive, heart, liver, neurological and airway cell and tissue models.

8.
J Neurointerv Surg ; 2019 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-31530654

RESUMO

PURPOSE: To evaluate the effectiveness and safety of rescue stenting (RS) after failed mechanical thrombectomy (MT) for patients with large artery occlusion in the anterior circulation. METHODS: Consecutive patients who experienced failed reperfusion and subsequently did or did not undergo RS at 16 comprehensive stroke centers were enrolled from January 2015 to June 2018. Propensity score matching was used to achieve baseline balance between the patient groups. Symptomatic intracranial hemorrhage (sICH) at 48 hours and the modified Rankin Scale scores and mortality at 3 months in the two groups were compared. RESULTS: A total of 90 patients with RS and 117 patients without RS after failed MT were enrolled. Propensity score matching analysis selected 132 matched patients. The good outcome rate was significantly higher in matched patients with RS than in those without RS (36.4% vs 19.7%, p=0.033), whereas the sICH (13.6% vs 21.2%, p=0.251) and mortality (31.9% vs 43.9%, p=0.151) were not significantly different between the groups. CONCLUSIONS: RS seems to be an effective safe choice for patients with large vessel occlusion of the anterior circulation who underwent failed MT.

9.
Nat Cell Biol ; 21(9): 1164-1172, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31481796

RESUMO

Single-cell measurement of chromatin states, including histone modifications and non-histone protein binding, remains challenging. Here, we present a low-cost, efficient, simultaneous indexing and tagmentation-based ChIP-seq (itChIP-seq) method, compatible with both low cellular input and single cells for profiling chromatin states. itChIP combines chromatin opening, simultaneous cellular indexing and chromatin tagmentation within a single tube, enabling the processing of samples from tens of single cells to, more commonly, thousands of single cells per assay. We demonstrate that single-cell itChIP-seq (sc-itChIP-seq) yields ~9,000 unique reads per cell. Using sc-itChIP-seq to profile H3K27ac, we sufficiently capture the earliest epigenetic priming event during the cell fate transition from naive to primed pluripotency, and reveal the basis for cell-type specific enhancer usage during the differentiation of bipotent cardiac progenitor cells into endothelial cells and cardiomyocytes. Our results demonstrate that itChIP is a widely applicable technology for single-cell chromatin profiling of epigenetically heterogeneous cell populations in many biological processes.


Assuntos
Cromatina/metabolismo , Células Endoteliais/metabolismo , Processamento de Proteína Pós-Traducional/genética , Análise de Sequência de DNA , Animais , Sítios de Ligação , Imunoprecipitação da Cromatina/métodos , Epigenômica/métodos , Histonas/metabolismo , Camundongos Transgênicos , Análise de Sequência de DNA/métodos
10.
Zhen Ci Yan Jiu ; 44(8): 610-4, 2019 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-31475497

RESUMO

OBJECTIVE: To observe the clinical therapeutic effect of Fuyang-pot warming combined with electroacupuncture (EA) in the treatment of scapulohumeral periarthritis (SPA). METHODS: A total of 90 cases of SPA patients were randomized into EA, Fuyang-pot warming and EA plus Fuyang-pot warming (combination) groups (n=30 per group). Fuyang-pot warming including pressing, mild moxibustion, scraping-pushing, cupping, tapping, etc. was applied to Fengchi (GB20), Dazhui (GV14), Jianjing (GB21), Jianyu (LI15), Zhongfu (LU1), Ashi-point, etc., and EA (2 Hz /100 Hz,1-1.5 mA) was appled to GB20, GV14, GB21, LI15, Binao (LI14), Tiaokou (ST38), Chengshan (BL57), Ashi-point, etc. The treatment was performed for 30 min every time, once every other day for 2 weeks. The visual analogue scale (VAS, 0-10 points) was used to assess the pain severity. The Constant-Murley shoulder assessment scale (100 points in total, including 15 points in pain severity and 20 points in daily living activities, 40 points in joint motion range, and 25 points in myodynamia) was used to assess the functional state of the shoulder. The rating scale of the American Shoulder and Elbow Surgeons (ASES, 4 grades) was used to evaluate the ability of daily living activities. RESULTS: Following the treatment, intra-group comparison showed that the VAS score was significantly reduced in the three groups in comparison with their own pre-treatment (P<0.01). The total scores of Constant-Murley scale, and scores of activities of daily living and active motion range, myodynamia, and ASES shoulder-joint function were all considerably increased in the three groups in comparison with their own pre-treatment (all P<0.01). The therapeutic effect of EA plus Fuyang-pot warming was significantly superior to that of simple EA and simple Fuyang-pot warming in reducing VAS score and increasing total score of Constant-Murley scale and scores of activities of daily living, active motion range, myodynamia as well as ASES shoulder joint function (P<0.01). Of the 30, 29 and 30 cases in the combination, EA and Fuyang-pot warming groups, 9, 2 and 4 were basically cured, 14, 8 and 12 experienced marked improvement, 4, 12 and 9 were improved, and 3, 7 and 5 failed in the treatment, with the cured plus effective rates being 76.67%, 34.48% and 53.33%, respectively. The cure plus effective rate was apparently higher in the combined treatment group than in the simple EA and simple Fuyang-pot warming groups (P<0.01), but had no significant difference between the simple EA and simple Fuyang-pot warming groups (P>0.05). CONCLUSION: Fuyang-pot warming combined with EA is effective in relieving pain, and enhancing the daily life quality in scapulohumeral periarthritis patients.


Assuntos
Eletroacupuntura , Moxibustão , Periartrite , Atividades Cotidianas , Pontos de Acupuntura , Humanos , Periartrite/terapia
11.
J Nat Prod ; 82(9): 2419-2429, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31503490

RESUMO

Eight new limonoids, toononoids A-H (1-8), eight new B-seco-29-norlimonoids, toonanoronoids A-H (9-16), and seven known analogues were obtained from the EtOAc extract of the twigs and leaves of Toona ciliata. Compounds 2, 4, 8, and 16 are rare lactam-bearing limonoids. Compounds 1, 14, and 15 possess an unusual γ-methoxybutenolide moiety at C-17, while compounds 9, 10, and 15 have a rare 3ß-hydroxy group. Their 2D structure and relative configurations were identified using spectroscopic data. The absolute configurations of 1, 9, 14, and 15 were established via X-ray diffraction crystallography or comparison of experimental and calculated ECD data. The cytotoxicity of the compounds was assessed toward five human tumor cell lines, and their anti-inflammatory activity was assessed based on NO production using LPS-stimulated RAW264.7 macrophages. Compounds 11 and 12 exerted inhibition toward two tumor cell lines (MCF-7, SW-480) with IC50 values between 2.1 and 3.7 µM, while 18-22 inhibited the proliferation of HL-60, MCF-7, and SW-480 cells (IC50 0.6-4.0 µM). Only compound 4 exhibited weak anti-inflammatory activity with an IC50 value of 28.3 µM.

12.
J Physiol Sci ; 69(6): 861-873, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31392590

RESUMO

Exercise has an effect on the reduction of myocardial fibrosis in diabetic rats as previously reported, in which oxidative stress and the TGF-ß1/Smad signaling pathway may play key roles. There is little direct experimental evidence that exercise alleviates myocardial fibrosis in type 2 diabetes mellitus (T2DM). Here we established a type 2 diabetic model by using streptozotocin and a high-fat diet. Rats were divided into groups of normal control (NC), T2DM and T2DM plus exercise (T2DME). The T2DME group received further treadmill training at moderate intensity for 8 weeks. Histological and biochemical methods were used to detect the benefits of exercise to T2DM. Results showed that the weight of rats in the T2DM group dropped dramatically, along with significant increases in blood glucose, myocardial fibrosis and oxidative stress, associated with upregulated expression of factors of myocardial fibrosis, except Smad7. Exercise largely reversed T2DM-induced alterations in factors of myocardial fibrosis, including suppressing expression of MMP-2, CTGF, TGF-ß1, p-Smad2 and p-Smad3, and increased expression of TIMP-1 and Smad7. Therefore, exercise might be considered an alternative therapeutic remedy for diabetic cardiomyopathy.

13.
Chin Med J (Engl) ; 132(17): 2066-2072, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31425357

RESUMO

BACKGROUND: Unpredictable difficult laryngoscopy (DL) remains a challenge for anesthesiologists, especially when difficult ventilation occurs during standard laryngoscopy. Accurate airway assessment should always be performed, but the common airway assessment methods only perform superficial screening. Thus, the deep laryngopharyngeal anatomy may not be evaluated. Ultrasound-based airway assessment has been recently proposed as a useful, simple, and non-invasive bedside tool as an adjunct to clinical methods, which may facilitate identification of DL. The present study aimed to determine the correlation between ultrasound-measured indicators and DL. METHODS: Patients undergoing elective surgery under general anesthesia with tracheal intubation were enrolled. Ultrasonic airway assessments were performed before anesthesia induction. Ultrasound diagnostic indicators included the thickness and width of the base of the tongue, the angle between the epiglottis and glottis, the length of the thyrohyoid membrane, and the thickness of the lateral pharyngeal wall. A score of ≥3 in the Modified Cormack-Lehane Scoring System was used as a standard of DL and was also applied to divide patients into DL and non-DL groups. The area under the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic ability of various diagnostic indicators. RESULTS: A total of 499 patients were enrolled into non-DL and DL groups comprising 452 (452/499, 90.6%) and 47 (47/499, 9.4%) patients, respectively. One ultrasonic diagnoses indicator correlated with DL, namely, the angle between the epiglottis and glottis. When the angle between the epiglottis and glottis was 50°, the area under the ROC curve was maximum (0.902), and the best sensitivity (81%) and specificity (89%) were achieved. CONCLUSIONS: Airway ultrasounds should be considered to identify DL. The ultrasonic angle measured between the epiglottis and glottis is highly associated with DL, which may occur when the angle is less than 50°. CLINICAL TRIAL REGISTRATION: ChiCTR-DDT-13004102, http://www.chictr.org.cn/showproj.aspx?proj=5465.

14.
Surg Endosc ; 33(11): 3864-3873, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31376013

RESUMO

BACKGROUND: Endoscopic full-thickness resection (EFTR) provides a significant advancement to the treatment of gastrointestinal submucosal tumors (SMTs). However, technological challenges, particularly in the gastric fundus, hinder its wider application. Here, we investigated the efficacy of a simple traction method that used dental floss and a hemoclip (DFC) to facilitate EFTR. METHODS: Between July 2014 and December 2016, we retrospectively reviewed data from all patients with SMTs in the gastric fundus originating from the muscularis propria layer that were treated by EFTR at Zhongshan Hospital of Fudan University. Baseline characteristics and clinical outcomes, including procedure time and complications rate, were compared between groups of patients receiving DFC-EFTR and conventional EFTR. RESULTS: A total of 192 patients were included in our analysis (64 in the DFC-EFTR group and 128 in the conventional EFTR group). Baseline characteristics for the two groups were similar. The mean time for DFC-EFTR and conventional EFTR was 44.2 ± 24.4 and 54.2 ± 33.2 min, respectively (P = 0.034). Although no serious adverse events presented in any of our cases, post-EFTR electrocoagulation syndrome (PEECS), as a minor complication, was less frequent in the DFC-EFTR group (3.1% vs. 12.5%, P = 0.036). Univariate and multivariate analysis identified that DFC, when used in EFTR, played a significant role in reducing procedure time and the rate of PEECS. The mean procedure time was significantly shorter in the DFC-EFTR group for lesions over 1.0 cm (P = 0.005), when the lesions were located in the greater curvature of the gastric fundus (P = 0.025) or when the lesions presented with intraluminal growth (P = 0.032). Moreover, when EFTR was carried out by experts, the mean procedure time was 20.4% shorter in the DFC-EFTR group (P = 0.038). CONCLUSIONS: This study indicated that DFC-EFTR for SMTs in the gastric fundus resulted in a shorter procedure time and reduced the risk of PEECS, a minor complication.

15.
Fetal Pediatr Pathol ; : 1-8, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31268384

RESUMO

Objectives: We evaluated the epidemiological features and various inflammatory markers in hospitalized children with influenza virus infection in China. Methods: The real-time RT-PCR assay was performed for detection and genotyping of influenza A and B virus. Th1/Th2 cytokines, WBC, and CRP were determined in influenza virus positive children. Results: H1N1 and Yamagata were the prevalent genotypes of influenza A and B virus in Hangzhou, respectively. IL-2, IL-10, and CRP were significantly increased and IFN-γ was decreased in children with severe Influenza A virus infection, and TNF-α and IFN-γ levels were found to be significantly lower in children with severe Influenza B virus infection. Conclusion: Increased IL-2, IL-10, and CRP with decreased IFN-γ may indicate a severe influenza A virus infection, and decreased TNF-α and IFN-γ may indicate a severe influenza B virus infection in children.

16.
Molecules ; 24(15)2019 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-31357480

RESUMO

We have previously shown that compound-7g inhibits colorectal cancer cell proliferation and survival by inducing cell cycle arrest and PI3K/AKT/mTOR pathway blockage. However, whether it has the ability to exert antitumor activity in other cancer cells and what is the exact molecular mechanism for its antiproliferation effect remained to be determined. In the present study, compound-7g exhibited strong activity in suppressing proliferation and growth of glioblastoma cells. The inhibitor selectively downregulated F-box protein SKP2 expression and upregulated cell cycle inhibitor p27, and then resulted in G1 cell cycle arrest. Mechanism analysis revealed that compound-7g also provokes the down-regulation of E2F-1, which acts as a transcriptional factor of SKP2. Further results indicated that compound-7g induced an increase of LC3B-II and p62, which causes a suppression of fusion between autophagosome and lysosome. Moreover, compound-7g mediated autophagic flux blockage promoted accumulation of ubiquitinated proteins and then led to endoplasmic reticulum stress. Our study thus demonstrated that pharmacological inactivation of E2F-1-SKP2-p27 axis is a promising target for restricting cancer progression.

17.
J Chem Phys ; 150(23): 234101, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31228885

RESUMO

There has been a long history of applying the generalized master equation (GME) to study charge carrier and exciton transport in molecular systems. Yet exact memory kernels in the GME are generally difficult to obtain. In this work, exact memory kernels of the Nakajima-Zwanzig-Mori GME for a one dimensional Holstein type of model are calculated by employing the Dyson relation for the exact memory kernel, combined with the hierarchical equations of motion method. Characteristics of the exact memory kernels, as well as the transition rate constants within the Markovian approximation, are then analyzed for different sets of parameters ranging from the hopping to bandlike transport regimes. It is shown that, despite the memory effect of the exact kernels, the Markovian approximation to the exact GME can reproduce the diffusion constants accurately. We also investigate the validity of the second and fourth order perturbation theories with respect to the electronic coupling constant in calculating the rate constants and the diffusion constant. It is found that, due to the cancellation of errors, the second order diffusion constant gives a reasonable estimate of the exact one within a wide range of electronic coupling constants.

18.
Nat Prod Bioprospect ; 2019 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-31214880

RESUMO

To enrich the bioactive cycloartane triterpenoid glycoside named actein and find out more cytotoxic cycloartane triterpenes, a phytochemical study of Cimicifuga foetida was conducted. 113 g (0.17%) actein was purified by recrystallization while eight cycloartane-type triterpenes (1-8) were isolated from the mother liquid. The chemical structures of new compounds (1-4) were elucidated by 1D and 2D NMR and HRESIMS spectroscopic analyses. Moreover, new compounds showed moderate and broad-spectrum cytotoxicity against 5 human cancer cell lines with IC50 values ranging from 4.02 to 15.80 µM.

19.
Bioinformatics ; 2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-31197306

RESUMO

MOTIVATION: Accurate delineation of protein domain boundary plays an important role for protein engineering and structure prediction. Although machine learning methods are widely used to predict domain boundary, these approaches often ignore long-range interactions among residues, which have been proven to improve the prediction performance. However, how to simultaneously model the local and global interactions to further improve domain boundary prediction is still a challenging problem. RESULTS: This article employs a hybrid deep learning method that combines Convolutional Neural Network (CNN) and gate recurrent units (GRU) models for domain boundary prediction. It not only captures the local and non-local interactions, but also fuses these features for prediction. Additionally, we adopt balanced Random Forest for classification to deal with high imbalance of samples and high dimensions of deep features. Experimental results show that our proposed approach (DNN-Dom) outperforms existing machine-learning-based methods for boundary prediction. We expect that DNN-Dom can be useful for assisting protein structure and function prediction. AVAILABILITY: The method is available as DNN-Dom Server at http://isyslab.info/DNN-Dom/. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

20.
Artigo em Inglês | MEDLINE | ID: mdl-31247541

RESUMO

OBJECTIVE: This paper proposes a wearable human motion tracking device using micro flow sensor incorporating with micro accelerometer, which allows detecting postures of human limbs in dynamic motions. METHODS: A micro flow sensor is used to detect motion velocity, from which motion acceleration can be estimated. Thereby the limb postures are figured out by using the components of the gravity acceleration that are determined by subtracting the motion accelerations from the accelerometer outputs. The motion tracking device is packaged in a watch-type case, which allows it wearable. A Kalman filter is employed to implement sensor data fusion. RESULTS: The motion velocity, motion acceleration, and postures of human limbs can be effectively detected by the proposed motion tracking device and methodology. Experiments including human limb tracking are conducted to validate the effectiveness of the proposed device and methodology. CONCLUSION: The experimental results show that the measurements of human limb motion and posture are feasible and free of accumulative errors. SIGNIFICANCE: The flow-aid motion tracking device is wearable, environmental restriction free and practicable for long-term monitoring, and provides a promising approach for physical rehabilitation, intelligent prosthesis, personal athletic training, and etc.

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