Design and fabrication of a novel linear oscillating conventional micro air pump

A novel permanent magnetically and electro-magnetically powered, linear oscillating conventional micro air pump was designed, fabricated and characterized. This new pump might be used in a wrist-type blood pressure monitor or other similar devices that require high air pressure discharge. Factors considered in designing this micro air pump include feature size (especially the thickness), operation voltage, efficiency, heat transfer, noise and weight. For evaluating the feasibility of this novel design, basic performance calculations and ANSYS magnetic flux simulations had been conducted before the first prototype was made. Both theoretical calculations and simulation results show that this novel design meets the requirements for use in a wrist-type blood pressure monitor. The developed pump prototype pump was able to achieve a maximum air pressure of 180 mmHg. Compared to an existing air pump used in a wrist-type blood pressure meter, this new design shows significant reduction in the thickness (reduced by 33%) as well as in the overall size (reduced by 50%). It is also quieter, environmentally friendly, and easily manufactured at low cost

Finished Genome Sequence of Collimonas arenae Cal35.

We announce the finished genome sequence of soil forest isolate Collimonas arenae Cal35, which comprises a 5.6-Mbp chromosome and 41-kb plasmid. The Cal35 genome is the second one published for the bacterial genus Collimonas and represents the first opportunity for high-resolution comparison of genome content and synteny among collimonads

Factors contributing to early breast-feeding cessation among Chinese mothers: An exploratory study

Background although more than 85% of all new mothers in Hong Kong now initiate breast feeding, few exclusively breast feed and the overall duration is short. More than one-third stop breast feeding within the first month post partum. Objective to explore the breast-feeding experiences of Hong Kong Chinese mothers who prematurely discontinue breast feeding and to identify contributing factors that might be remediated to help women breast feed longer. Design qualitative exploratory study. Methods in-depth, exploratory interviews were carried out with 24 new mothers who stopped breast feeding within one month after birth, and content analysis was used to analyse the data. Findings five core themes emerged from the data: unnatural expectations, left to figure it out, uncertainty, unfulfilling experiences, and guilt versus relief. Because breast feeding is ‘natural’ participants expected that it would come naturally and thus be easy. When breast feeding did not happen naturally, however, midwives were too busy to provide breast-feeding support and mothers were left to figure it out on their own. Participants also reported difficulty in gauging whether the infant was getting adequate nutrition from their breastmilk. Few participants had positive breast-feeding experiences; while the decision to stop breast feeding caused guilt for most participants, others expressed relief at stopping breast feeding. Key conclusions and implications for practice greater postnatal breast-feeding support, both in the hospital and after the mother returns home, would likely increase the mother׳s confidence and enhance her mothering experience. Further antenatal and postnatal education on the realistic breast-feeding expectations and the amount of breastmilk required by babies is also important. More research is needed to test professional and peer support breast-feeding interventions to provide guidance to policy makers on the most effective breast-feeding support strategies.postprin

A brown-world cascade in the dung decomposer food web of an alpine meadow: effects of predator interactions and warming

Top-down control has been extensively documented in food webs based on living plants, where predator limitation of herbivores can cascade to facilitate plant growth (the green-world hypothesis), particularly in grasslands and aquatic systems. Yet the ecosystem role of predators in detrital food webs is less explored, as is the potential effect of climate warming on detritus-based communities. We here show that predators have a brown-world role in decomposer communities via a cascading top-down control on plant growth, based on the results of an experiment that factorially manipulated presence and size of two predator species as well as temperature (warmed vs. unwarmed). The inclusion of predatory beetles significantly decreased abundance of coprophagous beetles and thus the rate of dung decomposition and productivity of plants growing surrounding the dung. Moreover, the magnitude of these decreases differed between predator species and, for dung loss, was temperature dependent. At ambient temperature, the larger predators tended to more strongly influence the dung loss rate than did the smaller predators; when both predators were present, the dung loss rate was higher relative to the treatments with the smaller predators but comparable to those with the larger ones, suggesting an antagonistic effect of predator interaction. However, warming substantially reduced dung decomposition rates and eliminated the effects of predation on dung decomposition. Although warming substantially decreased dung loss rates, warming only modestly reduced primary productivity. Consistent with these results, a second experiment exploring the influence of the two predator species and warming on dung loss over time revealed that predatory beetles significantly decreased the abundance of coprophagous beetles, which was positively correlated with dung loss rates. Moreover, experimental warming decreased the water content of dung and hence the survival of coprophagous beetles. These results confirm that the brown-world effect of predator beetles was due to cascading top-down control through coprophagous beetles to nutrient cycling and primary productivity. Our results also highlight potentially counterintuitive effects of climate warming. For example, global warming might significantly decrease animal-mediated decomposition of organic matter and recycling of nutrients in a future warmed world

Photoconfigurable, Cell-Remodelable Disulfide Cross-linked Hyaluronic Acid Hydrogels.

Dynamic photoresponsive synthetic hydrogels offer important advantages for biomaterials design, from the ability to cure hydrogels and encapsulate cells in situ to the light-mediated control of cell-spreading and tissue formation. We report the facile and effective photocuring and photoremodeling of disulfide-cross-linked hyaluronic acid hydrogels, based on photo-oxidation of corresponding thiol residues and their radical-mediated photodegradation. We find that the mechanical properties of disulfide hydrogels and the extent of their photoremodeling can be tuned by controlling the photo-oxidation and photodegradation reactions, respectively. This enables not only the photopatterning of the mechanical properties of hydrogels but also their self-healing and photomediated healing. Finally, we demonstrate the ability to encapsulate mesenchymal stromal cells within these materials and to regulate their protrusion and spreading in 3D matrices by controlling the mechanical properties of the disulfide networks. Therefore, synthetically accessible photoconfigurable disulfide hydrogels offer interesting opportunities for the design of soft biomaterials and the regulation of cell encapsulation and matrix remodeling for tissue engineering

Predictors and Consequences of In-hospital Formula Supplementation for Healthy Breastfeeding Newborns

BACKGROUND: Although exclusive breastfeeding is recommended for the first 6 months, the use of breast milk substitutes is widespread around the world. OBJECTIVES: To describe the patterns of infant formula supplementation among healthy breastfeeding newborns, to identify factors contributing to in-hospital formula supplementation, and to assess the dose-response relationship between the amount of in-hospital formula supplementation and the duration of any breastfeeding. METHODS: A sample of 1246 breastfeeding mother-infant pairs was recruited from 4 public hospitals in Hong Kong and followed prospectively for 12 months or until weaned. Multiple logistic regression analysis was used to examine factors associated with in-hospital supplementation. Cox regression analysis was used to explore the impact of in-hospital supplementation on breastfeeding duration. RESULTS: Of the total, 82.5% of newborns were supplemented in the hospital; one-half received formula within 5 hours of birth. Assisted vaginal delivery (odds ratio [OR] = 2.06, 95% confidence interval [CI] 1.03, 4.15), cesarean section (OR = 3.45, 95% CI 1.75, 6.80), and higher birth weight (OR = 1.56, 95% CI 1.12, 2.18) were positively associated with in-hospital formula supplementation, whereas initiating breastfeeding in the delivery room (OR = 0.55, 95% CI 0.33, 0.89) was associated with decreased likelihood of in-hospital supplementation. Any infant formula in the first 48 hours was associated with a shorter duration of breastfeeding (hazard ratio [HR] = 1.51, 95% CI 1.27, 1.80), but there was no dose-response effect. CONCLUSION: In-hospital formula supplementation is common in Hong Kong hospitals and appears to be detrimental to breastfeeding duration. Continued efforts should be made to avoid the provision of infant formula to breastfeeding babies while in the hospital unless medically indicated.postprin