A novel hybrid nanofluid was explored in order to find an efficient heat-transmitting fluid to replace standard fluids and revolutionary nanofluids. By using tangent hyperbolic hybrid combination nanoliquid with non-Newtonian ethylene glycol (EG) as a basis fluid and a copper (Cu) and titanium dioxide (TiO2) mixture, this work aims to investigate the viscoelastic elements of the thermal transferring process. Flow and thermal facts, such as a slippery extended surface with magnetohydrodynamic (MHD), suction/injection, form factor, Joule heating, and thermal radiation effects, including changing thermal conductivity, were also integrated. The Keller-Box method was used to perform collective numerical computations of parametric analysis using governing equivalences. In the form of graphs and tables, the results of TiO2-Cu/EG hybrid nanofluid were compared to those of standard Cu/EG nanofluid in important critical physical circumstances. The entropy generation study was used to examine energy balance and usefulness for important physically impacting parameters. Detailed scrutiny on entropy development get assisted with Weissenberg number, magnetic parameter, fractional volumes, injection parameter, thermal radiation, variable thermal conductivity, Biot number, shape variation parameter, Reynolds and Brinkman number. Whereas the entropy gets resisted for slip and suction parameter. In this case, spotted entropy buildup with important parametric ranges could aid future optimization.
Anion passivation effect on metal-oxide nano-architecture offers a highly controllable platform for improving charge selectivity and extraction, with direct relevance to their implementation in hybrid solar cells. In current work, we demonstrated the incorporation of fluorine (F) as an anion dopant to address the defect-rich nature of ZnO nanorods (ZNR) and improve the feasibility of its role as electron acceptor. The detailed morphology evolution and defect engineering on ZNR were studied as a function of F-doping concentration (x). Specifically, the rod-shaped arrays of ZnO were transformed into taper-shaped arrays at high x. A hypsochromic shift was observed in optical energy band gap due to the Burstein-Moss effect. A substantial suppression on intrinsic defects in ZnO lattice directly epitomized the novel role of fluorine as an oxygen defect quencher. The results show that 10-FZNR/P3HT device exhibited two-fold higher power conversion efficiency than the pristine ZNR/P3HT device, primarily due to the reduced Schottky defects and charge transfer barrier. Essentially, the reported findings yielded insights on the functions of fluorine on (i) surface -OH passivation, (ii) oxygen vacancies (Vo) occupation and (iii) lattice oxygen substitution, thereby enhancing the photo-physical processes, carrier mobility and concentration of FZNR based device.
Airway stem/progenitor epithelial cells (AECs) are notable for their differentiation capacities in response to lung injury. Our previous finding highlighted the regenerative capacity of AECs following transplantation in repairing tracheal injury and reducing the severity of alveolar damage associated acute lung injury in a rabbit model. The goal of this study is to further investigate the potential of AECs to re-populate the tracheal epithelium and to study their stimulatory effect on inhibiting pro-inflammatory cytokines, epithelial cell migration and proliferation, and epithelial-to-mesenchymal transition (EMT) process following tracheal injury. Two in vitro culture assays were applied in this study; the direct co-culture assay that involved a culture of decellularised tracheal epithelium explants and AECs in a rotating tube, and indirect co-culture assay that utilized microporous membrane-well chamber system to separate the partially decellularised tracheal epithelium explants and AEC culture. The co-culture assays provided evidence of the stimulatory behaviour of AECs to enhance tracheal epithelial cell proliferation and migration during early wound repair. Factors that were secreted by AECs also markedly suppressed the production of IL-1β and IL-6 and initiated the EMT process during tracheal remodelling.
Due to their sessile nature, plants are exposed to various environmental stressors such as exposure to high levels of harmful ultraviolet (UV), ionizing, and non-ionizing radiations. This exposure may result in various damages, ranging from DNA and chromosomal aberrations to phenotypic abnormalities. As an adaptation, plants have evolved efficient DNA repair mechanisms to detect and repair any damage caused by exposure to these harmful stressors to ensure their survival. In this study, the effects of gamma radiation (as a source of ionizing radiation) on clonal Ananas comosus var. MD2 was evaluated. The morphology and physiology of the clonal plantlets before and after exposure to gamma radiation were monitored at specific time intervals. The degree of genetic variation between the samples pre- and post-irradiation was also analyzed by using inter-simple sequence repeat (ISSR) markers. The resulting data revealed that the heights of the irradiated plantlets were significantly reduced (compared to control), but improved with the recovery period. Irradiated samples also exhibited relatively good photosynthetic efficiency that further improved as the plantlets recover. These observations were supported by the ISSR analysis, where the genetic dissimilarities between the irradiated samples and control were reduced by 0.1017, after 4 weeks of recovery. Overall, our findings suggested that the phenotype recovery of the clonal A. comosus var. MD2 plantlets was contributed by their ability to detect and repair the DNA lesions (as exemplified by the reduction in genetic dissimilarity after 4 weeks) and hence allow the plantlets to undergo phenotype reversion to normal plant stature.
The Malay people are an important ethnic composition in Southeast Asia, but their genetic make-up and population structure remain poorly studied. Here we conducted a genome-wide study of four geographical Malay populations: Peninsular Malaysian Malay (PMM), Singaporean Malay (SGM), Indonesian Malay (IDM) and Sri Lankan Malay (SLM). All the four Malay populations showed substantial admixture with multiple ancestries. We identified four major ancestral components in Malay populations: Austronesian (17%-62%), Proto-Malay (15%-31%), East Asian (4%-16%) and South Asian (3%-34%). Approximately 34% of the genetic makeup of SLM is of South Asian ancestry, resulting in its distinct genetic pattern compared with the other three Malay populations. Besides, substantial differentiation was observed between the Malay populations from the north and the south, and between those from the west and the east. In summary, this study revealed that the genetic identity of the Malays comprises a mixed entity of multiple ancestries represented by Austronesian, Proto-Malay, East Asian and South Asian, with most of the admixture events estimated to have occurred 175 to 1,500 years ago, which in turn suggests that geographical isolation and independent admixture have significantly shaped the genetic architectures and the diversity of the Malay populations.
Uncovering energy absorption and surface effects of various penetrating velocities on laminar structures is essential for designing protective structures. In this study, both quasi-static and dynamic penetration tests were systematical conducted on the front surfaces of metal sheets coated with a graphene oxide (GO) solution and other media. The addition of a GO fluid film to the front impact surface aided in increasing the penetration strength, improving the failure extension and dissipating additional energy under a wide-range of indentation velocity, from 3.33 × 10-5 m/s to 4.42 m/s. The coated -surfaces improved the specific energy dissipation by approximately 15~40% relative to the dry-contact configuration for both single-layer and double-layer configurations, and specific energy dissipations of double-layer configurations were 20~30% higher than those of the single-layer configurations. This treatment provides a facile strategy in changing the contact state for improving the failure load and dissipate additional energy.
Cryopreservation is the most promising way for long-term storage of biological samples e.g., single cells and cellular structures. Among various cryopreservation methods, vitrification is advantageous by employing high cooling rate to avoid the formation of harmful ice crystals in cells. Most existing vitrification methods adopt direct contact of cells with liquid nitrogen to obtain high cooling rates, which however causes the potential contamination and difficult cell collection. To address these limitations, we developed a non-contact vitrification device based on an ultra-thin freezing film to achieve high cooling/warming rate and avoid direct contact between cells and liquid nitrogen. A high-throughput cell printer was employed to rapidly generate uniform cell-laden microdroplets into the device, where the microdroplets were hung on one side of the film and then vitrified by pouring the liquid nitrogen onto the other side via boiling heat transfer. Through theoretical and experimental studies on vitrification processes, we demonstrated that our device offers a high cooling/warming rate for vitrification of the NIH 3T3 cells and human adipose-derived stem cells (hASCs) with maintained cell viability and differentiation potential. This non-contact vitrification device provides a novel and effective way to cryopreserve cells at high throughput and avoid the contamination and collection problems.
Copper zinc tin sulfide (CZTS) is a promising material for harvesting solar energy due to its abundance and non-toxicity. However, its poor performance hinders their wide application. In this paper gold (Au) nanoparticles are successfully incorporated into CZTS to form Au@CZTS core-shell nanostructures. The photocathode of Au@CZTS nanostructures exhibits enhanced optical absorption characteristics and improved incident photon-to-current efficiency (IPCE) performance. It is demonstrated that using this photocathode there is a significant increase of the power conversion efficiency (PCE) of a photoelectrochemical solar cell of 100% compared to using a CZTS without Au core. More importantly, the PCE of Au@CZTS photocathode improved by 15.8% compared to standard platinum (Pt) counter electrode. The increased efficiency is attributed to plasmon resonance energy transfer (PRET) between the Au nanoparticle core and the CZTS shell at wavelengths shorter than the localized surface plasmon resonance (LSPR) peak of the Au and the semiconductor bandgap.
Mycobacterium abscessus (Ma) is an emerging human pathogen that causes both soft tissue infections and systemic disease. We present the first comparative whole-genome study of Ma strains isolated from patients of wide geographical origin. We found a high proportion of accessory strain-specific genes indicating an open, non-conservative pan-genome structure, and clear evidence of rapid phage-mediated evolution. Although we found fewer virulence factors in Ma compared to M. tuberculosis, our data indicated that Ma evolves rapidly and therefore should be monitored closely for the acquisition of more pathogenic traits. This comparative study provides a better understanding of Ma and forms the basis for future functional work on this important pathogen.
Human adipose-derived stem cells (hADSCs) are easily isolated from fat tissue without ethical concerns, but differ in purity, pluripotency, differentiation ability, and stem cell marker expression, depending on the isolation method. We isolated hADSCs from a primary fat tissue solution using: (1) conventional culture, (2) a membrane filtration method, (3) a membrane migration method where the primary cell solution was permeated through membranes, adhered hADSCs were cultured, and hADSCs migrated out from the membranes. Expression of mesenchymal stem cell markers and pluripotency genes, and osteogenic differentiation were compared for hADSCs isolated by different methods using nylon mesh filter membranes with pore sizes ranging from 11 to 80 μm. hADSCs isolated by the membrane migration method had the highest MSC surface marker expression and efficient differentiation into osteoblasts. Osteogenic differentiation ability of hADSCs and MSC surface marker expression were correlated, but osteogenic differentiation ability and pluripotent gene expression were not.
In 2015, an unexpected multiple outbreak of dengue occurred in Guangdong, China. In total, 1,699 cases were reported, of which 1,627 cases were verified to have DENV infections by nucleic acid or NS1 protein, including 44 DENV-1, 1126 DENV-2, 18 DENV-3 and 6 DENV-4, and the other cases were confirmed by NS1 ELISA. Phylogenetic analyses of DENV-1 isolates identified two genotypes (I and V). The predominant DENV-2 outbreak isolates were the Cosmopolitan genotypes, which likely originated from Malaysia. The DENV-3 isolates were assigned into genotype I and genotype III. All 6 DENV-4 isolates from imported cases were likely originally from Cambodia, Thailand and the Philippines. The entomological surveillance showed a moderate risk for the BI index in Chaozhou and Foshan and a low risk in Guangzhou. The imported cases were mostly detected in Guangzhou and Foshan. Surprisingly, the most serious outbreak occurred in Chaozhou, but not in Guangzhou or Foshan. A combined analyses demonstrated the multiple geographical origins of this outbreak, and highlight the detection of suspected cases after the alerting of imported cases, early implementation of control policies and reinforce the vector surveillance strategies were the key points in the chain of prevention and control of dengue epidemics.
IL-10 is an immunomodulatory cytokine with a critical role in limiting inflammation in immune-mediated pathologies. The mechanisms leading to IL-10 expression by CD4(+) T cells are being elucidated, with several cytokines implicated. We explored the effect of IL-4 on the natural phenomenon of IL-10 production by a chronically stimulated antigen-specific population of differentiated Th1 cells. In vitro, IL-4 blockade inhibited while addition of exogenous IL-4 to Th1 cultures enhanced IL-10 production. In the in vivo setting of peptide immunotherapy leading to a chronically stimulated Th1 phenotype, lack of IL-4Rα inhibited the induction of IL-10. Exploring the interplay of Th1 and Th2 cells through co-culture, Th2-derived IL-4 promoted IL-10 expression by Th1 cultures, reducing their pathogenicity in vivo. Co-culture led to upregulated c-Maf expression with no decrease in the proportion of T-bet(+) cells in these cultures. Addition of IL-4 also reduced the encephalitogenic capacity of Th1 cultures. These data demonstrate that IL-4 contributes to IL-10 production and that Th2 cells modulate Th1 cultures towards a self-regulatory phenotype, contributing to the cross-regulation of Th1 and Th2 cells. These findings are important in the context of Th1 driven diseases since they reveal how the Th1 phenotype and function can be modulated by IL-4.
Endoplasmic reticulum (ER) stress has been implicated in the development of hypertension 3 through the induction of endothelial impairment. As 3',4'-dihydroxyflavonol (DiOHF) 4 reduces vascular injury caused by ischaemia/reperfusion or diabetes, and flavonols have been demonstrated to attenuate ER stress, we investigated whether DiOHF can protect mice from ER stress-induced endothelial dysfunction. Male C57BLK/6 J mice were injected with tunicamycin to induce ER stress in the presence or absence of either DiOHF or tauroursodeoxycholic acid (TUDCA), an inhibitor of ER stress. Tunicamycin elevated blood pressure and impaired endothelium-dependent relaxation. Moreover, in aortae there was evidence of ER stress, oxidative stress and reduced NO production. This was coincident with increased NOX2 expression and reduced phosphorylation of endothelial nitric oxide synthase (eNOS) on Ser1176. Importantly, the effects of tunicamycin were significantly ameliorated by DiOHF or TUDCA. DiOHF also inhibited tunicamycin-induced ER stress and apoptosis in cultured human endothelial cells (HUVEC). These results provide evidence that ER stress is likely an important initiator of endothelial dysfunction through the induction of oxidative stress and a reduction in NO synthesis and that DiOHF directly protects against ER stress- induced injury. DiOHF may be useful to prevent ER and oxidative stress to preserve endothelial function, for example in hypertension.
Plasmacytoid dendritic cells (pDC) are activators of innate and adaptive immune responses that express HLA-DR, toll-like receptor (TLR) 7, TLR9 and produce type I interferons. The role of human pDC in malaria remains poorly characterised. pDC activation and cytokine production were assessed in 59 malaria-naive volunteers during experimental infection with 150 or 1,800 P. falciparum-parasitized red blood cells. Using RNA sequencing, longitudinal changes in pDC gene expression were examined in five adults before and at peak-infection. pDC responsiveness to TLR7 and TLR9 stimulation was assessed in-vitro. Circulating pDC remained transcriptionally stable with gene expression altered for 8 genes (FDR
The effective solution to avoid machinery damage caused by resonance has been perplexing the field of engineering as a core research direction since the resonance phenomenon was discovered by Euler in 1750. Numerous attempts have been performed to reduce the influence of resonance since the earlier of last century, by introducing a nonlinear structure or a closed-loop control system. However, the existed methodologies cannot eliminate resonance completely even extra problems were introduced inevitably, which means the technical choke-point of resonance-free remains unsolved. Here we propose a designable archetype model, which establishes a mapping between the mechanical properties and its structure. A general inverse method for structure construction is proposed based upon the required property for the system with quasi-zero stiffness of any designed finite order and the zero-stiffness properties. It is shown that an ellipse trajectory tracking of the designed model is the sufficient and necessary condition to satisfy the zero-stiffness property. Theoretical analysis shows that no resonant response happens in a zero-stiffness system to the full-band frequency excitation, or equivalently, the system can completely isolate the energy transfer between the load and environment, when the damping ratio approaches zero. Finally, an experimental rig for the prototype structure is built up according to the sufficient and necessary condition of the zero-stiffness system, for which the special dynamic behaviours are verified through experiments of frequency-sweep and random-vibration as well. Experimental results show that the prototype of the initial vibration isolation frequency of zero-stiffness system is much lower than 0.37 Hz, and the vibration attenuation of the proposed model is about 16.86 dB, 45.63 dB, and 112.37 dB at frequencies of 0.37 Hz, 1 Hz, and 10 Hz, respectively. The distinguished geometric structure of the zero-stiffness system leads to a new inspiration for the design of resonance-free in metamaterial unit and the inverse method can even adapt the design for a more targeted applications based on an arbitrary complex dynamic requirement.
Helicobacter pylori at multiplicity of infection (MOI ≥ 50) have been shown to cause apoptosis in RAW264.7 monocytic macrophage cells. Because chronic gastric infection by H. pylori results in the persistence of macrophages in the host's gut, it is likely that H. pylori is present at low to moderate, rather than high numbers in the infected host. At present, the effect of low-MOI H. pylori infection on macrophage has not been fully elucidated. In this study, we investigated the genome-wide transcriptional regulation of H. pylori-infected RAW264.7 cells at MOI 1, 5 and 10 in the absence of cellular apoptosis. Microarray data revealed up- and down-regulation of 1341 and 1591 genes, respectively. The expression of genes encoding for DNA replication and cell cycle-associated molecules, including Aurora-B kinase (AurkB) were down-regulated. Immunoblot analysis verified the decreased expression of AurkB and downstream phosphorylation of Cdk1 caused by H. pylori infection. Consistently, we observed that H. pylori infection inhibited cell proliferation and progression through the G1/S and G2/M checkpoints. In summary, we suggest that H. pylori disrupts expression of cell cycle-associated genes, thereby impeding proliferation of RAW264.7 cells, and such disruption may be an immunoevasive strategy utilized by H. pylori.
Recycling is a process carried out by various organizations and individuals to enhance the environment's long-term sustainability. Some youth think that recycling is a monotonous action as it may seem inconvenient, less aware of the environmental issues and more time-consuming than they think and rather go for video games. Therefore, this study investigates the relationship between motivation and recycling intention in gamified learning among youth. To address the research aim, this study uses gamification as a motivational driver for a game-like learning experience to improve recycling intentions among youth. Self-determination theory (SDT) and the theory of Planned Behavior (TPB) will be this study's main motivational and behavioral theories. (n = 124) high schools and college students were invited to take part in an online gamified recycling activity, Edcraft Gamified Learning (EGL), consisting of two levels of gamified unused plastic-crafting recycling activities. After the activity, the participants will answer a post-event questionnaire and the data collected were analyzed. The result shows that controlled motivation (CM) and autonomous motivation (AM) positively influenced youth attitudes and social norms. Besides, attitude is the only psychosocial determinant that positively influences the recycling intention of the youth. Gamification only moderates positively between attitude and recycling intention. This study has clearly shown the effectiveness of gamified learning activity towards recycling intention directly and as a component that moderates the relationship between attitude and recycling intention, which shows a favorable evaluation towards recycling intention with gamified learning involved. Moreover, the findings showed that not all relationships are positive in a gamified learning environment, and it gives a good view on the weakness and strengths with the guideline of SDT and TPB.
Rice brown spot (BS) exerts devastating agronomic effects on grain quality and overall productivity. In Peninsular Malaysia, BS disease incidence is fairly prevalent and little is known about the diversity of BS pathogens in the local granaries. Fifteen isolates from BS symptomatic rice plants were identified at five different rice granaries across Peninsular Malaysia. Based on the morphological and molecular analyses, two isolates were confirmed as Bipolaris oryzae while the rest were identified as Exserohilum rostratum. Phylogenetic tree analysis revealed that BS incidence in rice granaries in Peninsular Malaysia is caused by a pair of closely related fungal pathogens, E. rostratum and B. oryzae, with the former being more predominant. Cultural characterization of E. rostratum isolate KT831962 showed the best growth and sporulation activity on corn meal agar plates incubated in complete darkness. The effects of calcium silicate (CaSiO3) and rice husk ash (RHA) soil amendment against MR219 and MR253 rice varieties were evaluated during rice-E. rostratum interaction. Results showed that soil amelioration using CaSiO3 and RHA singly and in combination with manganese (Mn) significantly reduced rice BS disease severity. The BS disease index was reduced significantly to less than 31.6% in the silicon-treated rice plants relative to the control plants at 41.2%. Likewise, the grain yield at the harvest stage showed significantly higher yield in the Si-treated rice plants in comparison to the control, non-Si treated rice plants. The findings highlight the potential of RHA agro-waste as Si fertilizer in a sustainable rice production system.
Basal stem rot (BSR) of oil palm is a disastrous disease caused by a white-rot fungus Ganoderma boninense Pat. Non-ribosomal peptides (NRPs) synthesized by non-ribosomal peptide synthetases (NRPSs) are a group of secondary metabolites that act as fungal virulent factors during pathogenesis in the host. In this study, we aimed to isolate NRPS gene of G. boninense strain UPMGB001 and investigate the role of this gene during G. boninense-oil palm interaction. The isolated NRPS DNA fragment of 8322 bp was used to predict the putative peptide sequence of different domains and showed similarity with G. sinense (85%) at conserved motifs of three main NRPS domains. Phylogenetic analysis of NRPS peptide sequences demonstrated that NRPS of G. boninense belongs to the type VI siderophore family. The roots of 6-month-old oil palm seedlings were artificially inoculated for studying NRPS gene expression and disease severity in the greenhouse. The correlation between high disease severity (50%) and high expression (67-fold) of G. boninense NRPS gene at 4 months after inoculation and above indicated that this gene played a significant role in the advancement of BSR disease. Overall, these findings increase our knowledge on the gene structure of NRPS in G. boninense and its involvement in BSR pathogenesis as an effector gene.