Search

An investigation of Leptadenia pyrotechnica (Forsk.) Decne (Asclepiadaceace) chemical constituents led to the isolation of six flavonoids, kaempferol-3- O-α-rhamnopyranosyl (1′″→6″)- O-β--glucopyranoside (E-I.1), kaempferol-3- O-β--rhamnopyranosyl (1′″→6″)- O-β--glucopyranoside (E-I.2), texasin-7- O-β-glucopyranoside E-II.2, kaempferol-3- O-β--glucopyranoside (E-III.1), kaempferol (E-IV.1) and kaempferide-3- O-α--rhamnopyranosyl (1′″→6″)- O-β-glucopyranoside (E-I.1a). The isolation of these compounds was carried out using Sephadex LH-20 low pressure liquid chromatography (LPLC), preparative paper chromatography (PC), and high performance liquid chromatography (HPLC). The chemical structures of the isolated compounds were established by mass spectrometry (FAB- and EI- techniques), nuclear magnetic resonance NMR (1H-, 13C- and COSY) spectral data and ultraviolet (UV) spectroscopic techniques. The acute toxicity of total alcoholic and total flavonoid extracts were examined by brine shrimp. The LC50 values were 11.89 and 84.14 ppm for the total alcoholic and total flavonoid extracts, respectively. The mortality rates of the isolated flavonoid fractions of E-I, E-I.1, E-I.2 represent the higher percentages of mortality compared with the rest of the flavonoid fractions. The plant exhibited activity as an antitumor agent in the initial potato disc screen. [ABSTRACT FROM AUTHOR]

A calibration-free localization algorithm for sensor actuator networks is presented in this paper. The algorithm uses sequential importance sampling to estimate the location of a number of limited-capability sensors, using the strength of the signals transmitted from the sensor node to GPS-enabled mobile actuator nodes that work as anchor nodes. Simulation results show that the algorithm converges to an error range of 1 m in approximately 10 time steps, for very small Rice factors and four anchor nodes. The algorithm was verified using the Network Simulator NS-2.28. [ABSTRACT FROM AUTHOR]

Focuses on the design of the Rover technology. Specification; Development of the system; Association of wireless access infrastructure with Rover clients.

The demand for a ubiquitous and accurate indoor localization service is continuously growing. Cellular-based systems are a good candidate to provide such ubiquitous service due to their wide availability worldwide. One of the main barriers to the accuracy of such services is the large number of models of cell phones, which results in variations of the measured received signal strength (RSS), even at the same location and time. In this paper, we propose OmniCells++ , a deep learning-based system that leverages cellular measurements from one or more training devices to provide consistent performance across unseen tracking phones. Specifically, OmniCells++ uses a novel approach to multi-task learning based on LSTM encoder–decoder models that allows it to learn a rich and device-invariant RSS representation without any assumptions about the source or target devices. OmniCells++ also incorporates different modules to boost the system's accuracy with RSS relative difference-based features and improve the deep model's generalization and robustness. Evaluation of OmniCells++ in two realistic testbeds using different Android phones with different form factors and cellular radio hardware shows that OmniCells++ can achieve a consistent median localization accuracy when tested on different phones. This is better than the state-of-the-art indoor cellular-based systems by at least 148%. [ABSTRACT FROM AUTHOR]

WiFi time of flight (ToF) measurement has been supported recently by the wireless LAN protocols to improve WiFi localization. Specifically, the IEEE 802.11-2016 standard has a fine-time measurement (FTM) protocol that can be used to measure the WiFi signal round trip time (RTT). In this paper, we present the design and implementation of WiNar, a WiFi RTT-based indoor location determination system that combines the advantages of both fingerprint and ranging-based techniques to overcome the different challenges of indoor environments. Using commercial-off-the-shelf access points and mobile phones, WiNar leverages both the propagation time and received signal strength of the wireless signal with a fingerprinting model to address the multipath, non-line-of-sight, signal attenuation, and interference challenges of the indoor environments. Moreover, when leveraging the round trip time measurements, WiNar does not require clock synchronization between the transmitter and the receiver. We discuss the different components of the system and its implementation on the Android operating system. Our results show that WiNar has a sub-meter localization accuracy with an average localization error of less than 0.77 meters for two different testbeds. This accuracy outperforms the performance of the traditional signal strength (RSS) fingerprinting technique by at least 50% and ranging-based multi-lateration technique by at least 193%. Finally, our system is also robust to heterogeneous devices. [ABSTRACT FROM AUTHOR]

Background: Despite the well-documented associations between poor maternal oral health and increased risk for adverse birth outcomes and dental caries in children after birth, prenatal oral health care is under-utilized, especially among the underserved population. In addition, oral Candida has recently been suggested as a potential culprit for children's dental caries, with evident maternal contributions. Therefore, this study aimed to obtain epidemiological data on the oral health and oral Candida carriage in a cohort of underserved US pregnant women, and reveal factors associated with their oral Candida carriage.Methods: Demographic-medical-oral hygiene practice data were collected. Comprehensive oral examination was conducted. Caries status and plaque index were recorded. Oral samples (saliva, plaque and swab) were processed to identify Candida species and Streptococcus mutans by culturing-dependent and -independent methods. Multiple logistic regression analyses were used to identify factors associated with oral Candida carriage and caries severity.Results: Eighty-two socioeconomically disadvantaged women (48 pregnant and 34 non-pregnant) were enrolled. More pregnant women (79.1%) had > = 1 untreated decayed tooth when compared to their non-pregnant counterparts (47.1%) (p = 0.01). The average number of decayed teeth in pregnant and non-pregnant women was 3.9 and 3.1 (p > 0.05). Caries severity was positively associated with race (African American vs. white), plaque index and salivary Candida albicans level. C. albicans was the most predominant/abundant Candida strain, with cheek and tonsil as the most common colonized sites. The detection of C. albicans was 56%/56% in saliva and 40%/47% in plaque of the pregnant and non-pregnant groups, respectively. Study women's oral Candida carriage is positively associated with hypertension [p = 0.03, odds ratio = 14.47(1.28, 163.51)], decayed teeth number [p = 0.04, odds ratio = 1.31 (1.01,1.69)] and salivary S. mutans level [p = 0.03, odds ratio = 4.80 (1.18-19.43)].Conclusions: Socioeconomically disadvantaged US women are in need of improved prenatal oral health, a large proportion of them have untreated decayed teeth and high carriage of oral Candida. Due to the observed significant association between the decayed teeth number and oral Candida carriage, providing oral health care during pregnancy (including limiting decayed teeth) will not only improve women's oral health, but also present as a promising approach to reduce oral Candida carriage in women. [ABSTRACT FROM AUTHOR]

We present CrowdMeter : a participatory system that leverages the sensed data collected from users' phones during their daily train commutes to gauge the real-time congestion level in railway stations. CrowdMeter tracks the passenger's position in the station as well as identifies her/his context (e.g., waiting for a train, buying a ticket) along with her trajectory from the station's entrance to the train. Therefrom, CrowdMeter extracts novel features, based on the user's location and context, from the phone sensors. These features capture the passenger's behavior (e.g., the walking pattern) and the ambient environment characteristics (e.g., the ambient sound) that can indicate the surrounding congestion level along the passenger's route in a railway station. CrowdMeter utilizes the passengers' contexts to show the congestion level for each area such as crowd density in passageways and the queue length of ticketing machines. Both passengers and operators can easily recognize the more and less congested areas, which helps to support proper decision making in their trips and smarter guidance of crowds. Evaluation of CrowdMeter through a field experiment in 29 different train stations in Japan shows that it can infer the congestion levels accurately, highlighting its promise as a ubiquitous travel-support service. [ABSTRACT FROM AUTHOR]

Objectives: There are no studies that have reviewed the pre- and post-operative dental protocols for the management of congestive heart failure (CHF) patients before and after implantation of the left ventricular assist device (LVAD). The aim of the present study was to review the pre- and post-operative dental protocols reported in indexed literature related to the management of CHF patients before and after implantation of ventricular assist devices (VAD). Design: The addressed focused question was "Is there a protocol for the dental management of end-stage CHF patients before and after VAD implantation?" Indexed databases were searched using various keywords. Letters to the Editor, review articles, and commentaries/expert opinions were excluded. Results: Seven studies were included and processed for data extraction. The number of participants ranged between 1 and 32 individuals, with age ranging between 14 and 66 years. Dental extractions were performed in 5 studies, and in 2 studies scaling and root planing was done for the treatment of periodontal diseases. One study assessed odontogenic infective foci and other lesions of the oral soft and hard tissues as a preoperative protocol. Six of the 7 studies did not report a dental therapeutic protocol, which was followed for the pre and/or post-LVAD implantation. Conclusions: It is recommended that standardized protocols should be adopted that allow the delivery of safe and effective pre- and postoperative dental care to VAD patients. Such protocols may help influence the morbidity and mortality rates and simultaneously improve the overall quality of life in vulnerable patients. [ABSTRACT FROM AUTHOR]

We present a research vision for deep learning (DL) in the oceans, collating applications and use cases as well as identifying opportunities, constraints, and open research challenges. Integrating DL in underwater explorations can automate and scale up monitoring as well as highlight practical challenges in enabling underwater operations. [ABSTRACT FROM AUTHOR]

A novel series of 3,4-disubstitutued coumarin derivatives have been synthesized by the reaction of ethyl coumarin-3-carboxylate with pyrazole-3,5-dione and condensation of ethyl 7-hydroxycoumarin-3-carboxylate with 4,6-dibromo-3-amino phenol. Acylation with acetic anhydride and condensation of coumarin derivatives with 2-hydroxybenzaldehyde yielded the corresponding acetyl derivatives and 4-substituted pyrazole derivatives. Structures of the synthesized compounds were elucidated by spectral methods and elemental analysis. All the prepared derivatives were evaluated for their cytotoxicity against human breast carcinoma cell line (MCF-7). Compound VI showed the least IC50 value in MTT colorimetric assay as compared to that of the standard marketed drug staurosporin. [ABSTRACT FROM AUTHOR]

Recently, there have been a wide range of mobile computing and crowd-sourcing applications that leverage the proliferating sensing capabilities of smartphones. Many of these place a paramount importance on accurate user heading estimation. Such applications include dead-reckoning-based localization and many crowd-sensing applications where the user typically carry her phone in arbitrary positions and orientations relative to her body and her transportation mode. However, there is no general solution available to estimate the user's heading as current state-of-the-art focus on improving the phone orientation estimation, require the phone to be placed in a particular position, require a fixed transportation mode, require user intervention, and/or do not work accurately indoors. In this paper we present Humaine, a novel ubiquitous system that reliably and accurately estimates the user orientation relative to the Earth coordinate system. Humaine works accurately whether the user is riding a vehicle or walking indoors/outdoors for arbitrary cell phone positions and orientations relative to the user body. Moreover, it requires no prior-configuration nor user intervention. The system intelligently fuses the different inertial sensors widely available in off-the-shelf smartphones and employs statistical analysis techniques to their measurements to estimate the user orientation. Implementation of the system on different Android devices with 300 experiments performed at different indoor and outdoor testbeds shows that Humaine significantly outperforms the state-of-the-art in diverse scenarios, achieving a median accuracy of 14 and 16 for indoor and outdoor pedestrian users and 20 for in-vehicle users over a wide variety of phone positions. This is better than the-state-of-the-art by 523 % and 594 % for indoor and outdoor pedestrian users and 750 % for in-vehicle users. This accuracy highlights the ubiquity of Humaine and its robustness against the various noise sources. [ABSTRACT FROM AUTHOR]

Recent FCC regulations on TV white spaces allow geo-location databases to be the sole source of spectrum information for white space devices. Geo-location databases protect TV band incumbents by keeping track of TV transmitters and their protected service areas, based on each transmitter location and transmission parameters using sophisticated propagation models. In this article, we show that keeping track of both TV transmitters and TV receivers (i.e., TV sets) can achieve significant improvement in the availability of white spaces. We first identify temporal and spatial wasted spectrum opportunities due to the current approach to white space detection. We then propose our DynaWhite architecture, which is responsible for orchestrating the detection and dissemination of highly dynamic, real-time, and fine-grained TV white space information, based on both TV transmitter and receiver information. DynaWhite proposes the development of a new generation of geo-location databases that combine conventional geo-location databases with novel unconventional sensing approaches based on the detection of passive TV receivers using standard cell phones. We present a quantitative evaluation of the potential gains, reaching 24 extra 6 MHz channels in some cases, in white space availability for potential deployments of DynaWhite. We finally identify research challenges associated with the adoption of our DynaWhite architecture. [ABSTRACT FROM PUBLISHER]

New quaternized salicylidene chitosan Schiff bases (QSCSBs) and their N-octyl derivatives (OQCs) have been synthesized and characterized, aiming to develop innovative antimicrobial and anti-biofilm agents. This research holds immense potential, as these compounds could be utilized as anti-biofouling additives in membrane technology in the future. The synthesis involved the modification of low molecular-weight-chitosan (LMC) through simultaneous Schiff base formation and quaternization processes to create QSCSBs. Subsequently, QSCSBs were catalytically reduced to form quaternized N-benzyl chitosan (QBCs) intermediates, which then underwent nucleophilic substitution reactions affording N-octyl quaternized chitosans (OQCs). Characterization techniques such as elemental, spectral, and microscopic analyses were used to confirm the successful synthesis of these materials. As membrane technology relies on surface charge, QSCSBs and OQCs with large zeta potentials could be used as positively charged additives. Moreover, SEM image revealed the regular distribution of pores and voids across the additives' surfaces raises intriguing questions about their implications for membrane performance. Meanwhile, the superior antibacterial and antibiofilm potential of these materials, particularly QSCSB2 and OQC2, indicate that the utilization of these compounds as anti-biofouling additives in membrane technology could significantly improve the performance and longevity of membranes used in various applications such as water treatment and desalination., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

One new compound ( 3f-[(7' R ,8' R )-4,4'-dihydroxy-5-methoxy-2,7'-cycloligna-7-en-9-methoxycarbonyl, 9'-carbonyl- O -] - β - D-fructofuranosyl- ( 2 → 1 )- α - D-glucopyranoside) (Moltkiopsin A) (2) was isolated and identified from the extract of aerial parts of the wild Egyptian plant Moltkiopsis ciliata (Frossk.), family Boraginaceae, for the first time, along with two aryldihydronaphthalene lignans 3f→9':6f→9-[(7' R ,8' R )-4,4'- dihydroxy-3,3',5-trimethoxy-2,7'-cycloligna-7-en-9,9'-dicarbonyl]-6g-acetyl- α -D-gluco pyranosyl-( 1 → 2 ) - β -D-fructofuranoside (Trigonotin A) (1) which was reported for the first time from this plant species and a known compound 3f→9':6f→9-[(7' R ,8' R )-4,4'- dihydroxy-3,3',5-trimethoxy-2,7'-cycloligna-7-en-9,9'-dicarbonyl]- α -D-gluco pyranosyl - ( 1 → 2 )- β -D- fructofuranoside (Trigonotin C) (3) . These compounds were separated and purified using different chromatographic techniques and their structures were elucidated by extensive 1D ( 1 H and 13 C NMR), and 2D NMR (COSY, HSQC, and HMBC), besides ESI-MS spectral methods. Extracts were screened as antioxidant, antitumor and antibacterial. The different extracts showed moderate to strong antioxidant capacities in DPPH assays. Ethyl acetate, methylene chloride and crude methanol extracts exhibited the most significant free radicals scavenging activity when compared to the standard antioxidant vitamin C. Hexane and butanol fractions showed the highest cytotoxicity against the cancer cell lines HepG2 and MCF-7.

A new series of cinnamide-fluorinated derivatives has been synthesized and characterized by using different spectroscopic and elemental microanalyses methods. All of the prepared p -fluorocinnamide derivatives were evaluated for their cytotoxic activity against the HepG2 liver cancerous cell line. The imidazolone derivative 6 , which bears N -( N -pyrimidin-2-ylbenzenesulphamoyl) moiety, displayed antiproliferative activity against HepG2 liver cancerous cells with an IC 50 value of 4.23 μM as compared to staurosporin (STU) (IC 50 = 5.59 μM). In addition, compound 6 experienced epidermal growth factor receptor (EGFR) inhibitory activity comparable to palatinib. The cell cycle analysis by flow cytometry indicated that compound 6 arrested the cellular cycle of HepG2 cells at the G1 phase. Additionally, as demonstrated by the fluorescence-activated cell sorting (FACS) technique, compound 6 increased both early and late apoptotic ratios compared to control untreated HepG2 cells. Moreover, imidazolone compound 6 induced apoptosis via the intrinsic apoptotic pathway by decreasing the level of mitochondrial membrane polarization (MMP) compared to untreated HepG2 cells. Therefore, the new N -( N -pyrimidin-2-ylbenzenesulphamoyl)imidazolone derivative 6 could be considered a potential platform for further optimizing an antitumor agent against hepatocellular carcinoma., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Objective: To systematically review the effect of electronic cigarette (e-cigarette) use on clinical, radiographic, and immunologic peri-implant parameters in males., Study Design: A comprehensive search of indexed databases was conducted to identify studies reporting data on both e-cigarette users and nonsmokers with implant-supported prosthesis with ≥1-year in function, up to May 2022. Marginal bone loss (MBL), probing depth (PD), plaque index (PI), and bleeding on probing (BOP) were recorded. Peri-implant sulcular fluid volume (PISF), tumor necrosis factor alpha (TNF-α) and interleukin 1β (IL-β) levels were also assessed. A meta-analysis was performed using random-effect models to determine the effect of e-cigarette use in primary and secondary outcomes., Results: Four cross-sectional studies were included with a total of 327 participants (165 e-cigarette users and 162 nonsmokers). All studies showed greater MBL, PI, PD, and lower BOP in e-cigarette users compared with never smokers. The meta-analysis indicated significant heterogeneity for all outcomes except MBL for distal implant surfaces, with the mean difference between e-cigarette users and nonsmokers of 0.89 mm (95% CI: 0.67-1.11, P < .01). The PISF volume, TNF-α, and IL-1β levels were increased in e-cigarette users (P < .01) with no heterogeneity present between studies., Conclusions: E-cigarette use shows a negative effect on clinical, radiographic, and immunologic parameters of dental implants., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Matrix metalloproteinase-9 (MMP-9) has been implicated as being an important pathogenic factor in inflammatory bowel disease (IBD). MMP-9 is markedly elevated in intestinal tissue of patients with IBD, and IBD patients have a defective intestinal tight-junction (TJ) barrier manifested by an increase in intestinal permeability. The loss of intestinal epithelial barrier function is an important contributing factor in the development and prolongation of intestinal inflammation; however, the role of MMP-9 in intestinal barrier function remains unclear. The purpose of this study was to investigate the effect of MMP-9 on the intestinal epithelial TJ barrier and to delineate the intracellular mechanisms involved by using in vitro (filter-grown Caco-2 monolayers) and in vivo (mouse small intestine recycling perfusion) systems. MMP-9 caused a time- and dose-dependent increase in Caco-2 TJ permeability. MMP-9 also caused an increase in myosin light-chain kinase (MLCK) gene activity, protein expression, and enzymatic activity. The pharmacological MLCK inhibition and siRNA-induced knockdown of MLCK inhibited the MMP-9-induced increase in Caco-2 TJ permeability. MMP-9 caused a rapid activation of the p38 kinase signaling pathway and inhibition of p38 kinase activity prevented the MMP-9-induced increase in MLCK gene activity and the increase in Caco-2 TJ permeability. MMP-9 also caused an increase in mouse intestinal permeability in vivo, which was accompanied by an increase in MLCK expression. The MMP-9-induced increase in mouse intestinal permeability was inhibited in MLCK-deficient mice. These data show for the first time that the MMP-9-induced increase in intestinal TJ permeability in vitro and in vivo was mediated by the p38 kinase signal transduction pathway upregulation of MLCK gene activity and that therapeutic targeting of these pathways can prevent the MMP-9-induced increase in intestinal TJ permeability. NEW & NOTEWORTHY MMP-9 is highly elevated in patients with IBD. IBD patients have compromised intestinal TJ barrier function manifested by an increase in intestinal permeability and intestinal inflammation. This study shows that MMP-9, at clinically achievable concentrations, causes an increase in intestinal TJ permeability in vitro and in vivo. In addition, a MMP-9-induced increase in intestinal TJ permeability was mediated by an increase in MLCK gene and protein expression via the p38 kinase pathway.