19672 research outputs found
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Application of Ti 3 C 2 MXene Quantum Dots for Immunomodulation and Regenerative Medicine
No full textInflammation is tightly linked to tissue injury. In regenerative medicine, immune activation plays a key role in rejection of transplanted stem cells and reduces the efficacy of stem cell therapies. Next-generation smart biomaterials are reported to possess multiple biologic properties for tissue repair. Here, the first use of 0D titanium carbide (Ti3C2) MXene quantum dots (MQDs) for immunomodulation is presented with the goal of enhancing material-based tissue repair after injury. MQDs possess intrinsic immunomodulatory properties and selectively reduce activation of human CD4+IFN-γ+ T-lymphocytes (control 87.1 ± 2.0%, MQDs 68.3 ± 5.4%) while promoting expansion of immunosuppressive CD4+CD25+FoxP3+ regulatory T-cells (control 5.5 ± 0.7%, MQDs 8.5 ± 0.8%) in a stimulated lymphocyte population. Furthermore, MQDs are biocompatible with bone marrow-derived mesenchymal stem cells and induced pluripotent stem cell-derived fibroblasts. Finally, Ti3C2 MQDs are incorporated into a chitosan-based hydrogel to create a 3D platform with enhanced physicochemical properties for stem cell delivery and tissue repair. This composite hydrogel demonstrates increased conductivity while maintaining injectability and thermosensitivity. These findings suggest that this new class of biomaterials may help bridge the translational gap in material and stem cell-based therapies for tissue repair and treatment of inflammatory and degenerative diseases. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei
Micro-arc oxidation of bioceramic coatings containing eggshell-derived hydroxyapatite on titanium substrate
No full textIn the present study eggshells-derived hydroxyapatite (EHA) coatings were successfully produced on Ti6Al4V substrates using micro-arc oxidation process (MAO) at various concentrations of EHA (i.e. 1, 1.5 and 2 g/L) in an electrolyte consisting of tri-sodium orthophosphate. The attributes of the coatings were determine by X-ray diffraction, attenuated total reflectance-fourier transform infrared spectroscopy, field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. The adhesion strength was evaluated using micro scratch tester, while the corrosion behavior of the MAO-coated substrates in phosphate buffer solution was determined by an electrochemical method. The results showed that as the EHA concentration increased, this was accompanied by a reduction in the porosity due to the formation of a dense and thick coating layer. This has also resulted in an increased in the surface roughness and degree of crsytallinity of the HA phase. The MAO-coated substrate prepared with 1.5 g/L EHA concentration exhibited a well-formed coating layer with improved adhesive strength and excellent corrosion resistance. The mechanism of EHA-coating formation as well as the enhanced corrosion resistance of the coated substrates were discussed. This research shows the viability of using calcium-rich waste eggshells to produce phase pure HA suitable for coating on Ti6Al4V substrate using MAO method. © 2019 Elsevier Ltd and Techna Group S.r.l
First report of extended-spectrum β-lactamases TEM-116 and OXA-10 in clinical isolates of alcaligenes species from Kuala Lumpur, Malaysia
No full textThere is an alarming increase in the prevalence of extended-spectrum β-lactamases (ESBLs) present mainly in Enterobacteriaceae and other nonfermenting gram-negative bacteria, such as Alcaligenes faecalis, which is the only species in that genus that is clinically relevant. We investigated Alcaligenes species from 7 cases (6 inpatients and one outpatient) at our tertiary-care hospital. Four patients had urinary tract infections, and one each had systemic lupus erythematosus, pulmonary stenosis, and diabetic ulcer. All 7 isolates were identified as Alcaligenes spp. based on their 16S rRNA gene sequences, and antibiotic susceptibility was determined using a Vitek 2 system with AST-GN87 cards. All the strains were resistant to cefazolin; 6 were resistant to trimethoprim/sulfamethoxazole; 5 manifested resistance to ampicillin/sulbactam, cefepime, tobramycin, ciprofloxacin, and nitrofurantoin; whereas 5 had multidrug resistance profiles. All the strains (7/7) expressed ESBL activity; PCR screening and sequencing showed evidence of genes blaTEM-116 (7/7) and blaOXA-10 (4/7), and we believe that this is the first report on the presence of TEM-116 and OXA-10 in an Alcaligenes spp. A combination of the 2 genes was present in 4 strains. All 7 strains were found to harbor at least one ESBL gene probably contributing to the drug resistance. © 2019, National Institute of Health. All rights reserved
Trogonoptera brookiana mollumar d’Abrera, Doggett & Parker, 1976 (Lepidoptera: Papilionidae), a subspecies or a synonym?
No full textThe birdwing butterfly Trogonoptera brookiana (Wallace, 1855) is a well-known conservation icon, yet questions remain about the infraspecific status of regional populations. The eastern Peninsular Malaysian population has been described as the subspecies mollumar d’Abrera, Doggett & Parker, 1976, but its status as a subspecies distinguishable from the taxon trogon (Vollenhoven, 1860) in Sumatra has been disputed. Wing characters and measurements of specimens from the two regions were therefore examined quantitatively using discriminant function and correspondence analyses. Eastern Peninsular specimens differ on average from Sumatran specimens in having more extensive green, especially in the female. This is reflected in many of the measurements and characters analysed. Females from the Peninsula also have a characteristically blacker upperside ground colour in which the outer areas of both wings barely contrast with the black veins and forewing cell. The extent of these differences enables a reliable differentiation of the females of both regions. The magnitude and consistency of differences are comparable to that between other subspecies of undisputed status. Behavioural differences also exist. The name mollumar therefore merits subspecific status. In addition, we consider the male forms walshi Haugum & Low, 1982 and walshoides Haugum & Low, 1982 to be chemically discoloured specimens of trogon rather than biological forms. © 2019, Museum National d'Histoire Naturelle. All rights reserved
Knowledge, utilization and barriers to primary care services for sexual and reproductive health among adolescents in secondary schools in selangor, Malaysia
No full textEarly sexual debut, partner violence, pregnancy and sexually transmitted infections contribute to negative health outcomes among adolescents. While the primary care clinics offer accessible sexual and reproductive health (SRH) services to adolescents, it is uncertain whether adolescents are aware of and utilize these services. This study aimed to examine Malaysian adolescents’ knowledge, utilization and barriers to primary care services for SRH. A cross-sectional survey was conducted from August to November 2011 among adolescent from five randomly selected schools in Selangor, Malaysia. A self-administered questionnaire was used to assess their knowledge, attitudes, sexual behaviors and utilization of SRH services. A total of 680 adolescents participated in the study. One in ten of the adolescents were aware of the availability of SRH services, and only 6.9% of them had ever visited a primary care clinic for SRH. About 75% of them felt uncomfortable going to a primary care clinic for SRH services. Knowledge and utilization of primary care clinics for SRH among adolescents in Malaysia is poor. © 2019 Malaysian Family Physician. All rights reserved
Determinants of shisha use among secondary school students in Sudan
No full textBackground: Shisha smoking has re-emerged in the Middle East in the last two decades and has spread rapidly in these communities. Information about shisha smoking in adolescents in Sudan is deficient. Hence, the aim of this study is to estimate the prevalence of shisha smoking among adolescents and determine the associated factors. Methods: This study is a school based cross sectional study among secondary school students in Khartoum State - Sudan that targets both male and female students aged 14-17 years. A total of 3387 students from 29 public and private schools were selected by multi stage random sampling. The participants completed an anonymous self-administered questionnaire which was based on Arabic version of the Global Youth Tobacco Survey (GYTS). Results: The response rate was 100% in schools and among participants, 57.3% were females and 51.6% were from public schools. The overall prevalence of those who had ever smoked shisha was 13.4%, and among male students the prevalence was 16.8%, while it was 10.9% in females. The associated factors were poor academic performance OR 2.90 CI 95% (1.21-6.94), friends smoking shisha OR 2.39 CI 95% (1.65-3.45), friends smoking cigarettes OR 2.76 CI 95% (1.90-4.01), peer pressure to smoke shisha OR 13.76 CI 95% (7.86-24.07) and unexpectedly restriction of selling shisha to minors OR 2.21 CI 95% (1.28-3.82). Conclusion: The prevalence of those who had ever smoked shisha is among the lowest in Middle East region; therefore, regular surveillance system is needed. A well-structured peer based comprehensive tobacco control programmes that are supported by strict and rigorous anti-tobacco regulations which control both commercial and social resources of tobacco are needed to contain this issue among adolescents. © 2019 The Author(s)
Baicalein and baicalin as Zika virus inhibitors
No full textAt present, there is no effective antiviral agent for Zika virus (ZIKV), an arbovirus that is known for its teratogenic effects on newborns. Baicalein and baicalin were found to be capable of downregulating ZIKV replication up to 10 hours postinfection, while prophylactic effects were evident in pre-treated cells. Baicalein exhibited its highest potency during intracellular ZIKV replication, whereas baicalin was most effective against virus entry. Our in silico interaction assays predicted that both compounds exhibited the strongest binding affinities towards ZIKV NS5, while the virus envelope glycoprotein was the least likely target protein. These findings serve as a crucial platform for further in-depth studies to decipher the underlying anti-ZIKV mechanism(s) of each compound. © 2018, Springer-Verlag GmbH Austria, part of Springer Nature
A severe form of M-protein negative distal acquired demyelinating symmetric neuropathy
No full textDistal acquired demyelinating symmetric neuropathy (DADS) is a variant of chronic inflammatory demyelinating polyneuropathy (CIDP) characterized by symmetrical, distal, sensory or sensorimotor involvement. DADS with M-protein (DADS-M) is less responsive to immunotherapy compared to those without M-protein (DADS-I). We report a case of DADS-I with severe clinical presentation viz. early hand involvement with marked wasting, inexcitable peripheral nerves on neurophysiology and poor response to immunotherapy. Despite the unusual presentation, ancillary tests including cerebrospinal fluid analysis, nerve biopsy and nerve ultrasound were supportive of an inflammatory demyelinating polyneuropathy. This case demonstrated the heterogeneity of the disorder and expands the clinical spectrum of DADS neuropathy. © 2019 Neurology India, Neurological Society of India
Multi-sensor fusion based on multiple classifier systems for human activity identification
No full textMultimodal sensors in healthcare applications have been increasingly researched because it facilitates automatic and comprehensive monitoring of human behaviors, high-intensity sports management, energy expenditure estimation, and postural detection. Recent studies have shown the importance of multi-sensor fusion to achieve robustness, high-performance generalization, provide diversity and tackle challenging issue that maybe difficult with single sensor values. The aim of this study is to propose an innovative multi-sensor fusion framework to improve human activity detection performances and reduce misrecognition rate. The study proposes a multi-view ensemble algorithm to integrate predicted values of different motion sensors. To this end, computationally efficient classification algorithms such as decision tree, logistic regression and k-Nearest Neighbors were used to implement diverse, flexible and dynamic human activity detection systems. To provide compact feature vector representation, we studied hybrid bio-inspired evolutionary search algorithm and correlation-based feature selection method and evaluate their impact on extracted feature vectors from individual sensor modality. Furthermore, we utilized Synthetic Over-sampling minority Techniques (SMOTE) algorithm to reduce the impact of class imbalance and improve performance results. With the above methods, this paper provides unified framework to resolve major challenges in human activity identification. The performance results obtained using two publicly available datasets showed significant improvement over baseline methods in the detection of specific activity details and reduced error rate. The performance results of our evaluation showed 3% to 24% improvement in accuracy, recall, precision, F-measure and detection ability (AUC) compared to single sensors and feature-level fusion. The benefit of the proposed multi-sensor fusion is the ability to utilize distinct feature characteristics of individual sensor and multiple classifier systems to improve recognition accuracy. In addition, the study suggests a promising potential of hybrid feature selection approach, diversity-based multiple classifier systems to improve mobile and wearable sensor-based human activity detection and health monitoring system. © 2019, The Author(s)
Lingual nerve neuropathy: more than just third molar surgery and inferior alveolar nerve blocks
No full textNeuropathy of the lingual nerve, when it occurs, often results from third molar surgery, or the provision of inferior alveolar nerve blocks. Investigators have reported that the anatomical location and the unpredictable course of the lingual nerve play important roles in it being affected by these procedures. However, there are many other causes of neuropathy with which most medical and dental practitioners are unfamiliar. This article briefly reviews the course of the lingual nerve, and summarizes the causes and reports of all uncommon aetiologies of neuropathy that can occur along the path of a lingual nerve. The clinical implication and management of lingual nerve neuropathy is discussed. © 2019 George Warman Publications. All rights reserved