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Enzyme Stabilization in Hierarchical Biocatalytic Food Packaging and Processing Materials
The partnership of biocatalysts and solid support materials provides many opportunities for bioactive packaging and bioprocessing aids beneficial to the agricultural and food industries. Biocatalysis, or reactions modulated by enzymes, allows bioactive materials to assist in bringing a substrate to product. Enzymes are proteins which catalyze reactions by lowering the activation energy required to drive the production of a desired product. Enzymes are commonly utilized in food processing as catalysts with specificity in order to enhance product quality through the production of beneficial food components, and to break down undesirable components that may be harmful or may decrease product quality. Enzymes are proteins with specificity for a substrate, that under the ideal conditions will speed bioprocessing by lowering the activation energy required to create a product.
As the working conditions for biocatalytic materials can be very specific, enzymes are often immobilized and incorporated onto and into solid supports in order extend their thermostability and pH optima as well. Integrating biocatalysts into food packaging also allows for extended use and clean-labeling when non-migratory, which may enable “in-package processing” where food constituents undergo changes to improve quality or shelf-life while in transport and storage. Immobilized enzymes are more readily recovered, regenerated, and reused – decreasing overall energy, material, and environment costs. Introducing biocatalytic materials to solid polymeric supports requires varied techniques in order to maintain activity. However, disadvantages to immobilizing techniques lead to activity loss and are attributed to denaturation, incorrect orientation, low protein loading, and material incompatibility. Denaturation and incorrect orientation are characteristic of proteins on hydrophobic surfaces. Covalent immobilization allows for food products to interact with non-migratory biocatalytic coatings without incorporating them into the food matrix. Cross-linker compatibility is an essential part of covalent attachment too. Cross-linkers utilize various functional groups to attach active ingredients to solid surfaces and stabilize polymers.
This work progresses through the advantages of covalent and non-covalent enzyme immobilization. First, lactase was immobilized for a bioactive packaging application by Layer by Layer conjugation to low-density polyethylene. Increasing layer deposition increased total protein loading, but did not increase activity per layer. Next, lactase was blended and embedded into polyethylene oxide for an electrospun nanofiber storage and dosing system maintaining up to 92% of free enzyme activity. Embedding and blending is often paired with cross-linking techniques to aid the support material maintain its physical properties. Immobilization of chymotrypsin onto nylon 6,6 demonstrated the benefit of nanoscale materials on retained activity, where the bulk material is water-insoluble. And finally, chymotrypsin was encapsulated by emulsion electrospinning into polycaprolactone with poly(vinyl alcohol) to increase biocompatibility with the solid support. These studies further demonstrate the robustness of enzymes incorporated into packaging materials is dependent on the processing technique and solid support and tether material.
Food and agriculture have recently turned to nanomaterials in processing and packaging due to the increased surface area to volume ratio, ease of manufacturing scale-up, and maintained or even improved mechanical stability of nanomaterials. Increased surface area provides for more functional surfaces. A combination of the nanoscale and curvature provided by nanofibers allows enzymes to behave like their free enzyme counterparts. Often nanomaterials may be made uniformly, which also benefits increasing processing efficiency for all industries.
The immobilization method must reduce diffusion limitations as well as aid activity retention for increased thermostability and pH stability by taking into account environmental interactions. Herein outlines methods for the incorporation of biocatalytic materials in active packaging by combining the benefits of enzyme immobilization at the nanoscale with complementary material interactions
Characterization of microRNA expression profiles in normal human tissues
<p>Abstract</p> <p>Background</p> <p>Measuring the quantity of miRNAs in tissues of different physiological and pathological conditions is an important first step to investigate the functions of miRNAs. Matched samples from normal state can provide essential baseline references to analyze the variation of miRNA abundance.</p> <p>Results</p> <p>We provided expression data of 345 miRNAs in 40 normal human tissues, which identified universally expressed miRNAs, and several groups of miRNAs expressed exclusively or preferentially in certain tissue types. Many miRNAs with co-regulated expression patterns are located within the same genomic clusters, and candidate transcriptional factors that control the pattern of their expression may be identified by a comparative genomic strategy. Hierarchical clustering of normal tissues by their miRNA expression profiles basically followed the structure, anatomical locations, and physiological functions of the organs, suggesting that functions of a miRNA could be appreciated by linking to the biologies of the tissues in which it is uniquely expressed. Many predicted target genes of miRNAs that had specific reduced expression in brain and peripheral blood mononuclear cells are required for embryonic development of the nervous and hematopoietic systems based on database search.</p> <p>Conclusion</p> <p>We presented a global view of tissue distribution of miRNAs in relation to their chromosomal locations and genomic structures. We also described evidence from the <it>cis</it>-regulatory elements and the predicted target genes of miRNAs to support their tissue-specific functional roles to regulate the physiologies of the normal tissues in which they are expressed.</p
A tighter constraint on Earth-system sensitivity from long-term temperature and carbon-cycle observations
Developing sound strategies to manage climate risks hinges critically on
Earth-system properties, including the Earth-system sensitivity (ESS). Current
ESS estimates are subject to large and deep uncertainties. Long-term carbon
cycle models can provide a useful avenue to constrain ESS, but previous efforts
either lack a formal data assimilation framework, or focus on discrete
paleoevents. Here, we improve on ESS estimates by using a Bayesian approach to
fuse deep-time paleoclimate CO2 and temperature data over the last 420 Myrs
with a long-term carbon cycle model. Our best sensitivity estimate of 3.4 deg C
(2.6-4.7 deg C; 5-95% range) shows a narrower range than previous assessments,
implying increased learning. Our sensitivity analyses indicate that during the
Cretaceous, a much weaker chemical weathering efficiency of gymnosperms and
shift in the timing of gymnosperm- to angiosperm-dominated vegetation yield
better agreement with temperature records. Research into improving the
understanding about these plant-assisted weathering mechanisms hence provides
potentially powerful avenues to further constrain this fundamental Earth-system
property
Rotating Objects via In-Hand Pivoting using Vision, Force and Touch
We propose a robotic manipulation system that can pivot objects on a surface
using vision, wrist force and tactile sensing. We aim to control the rotation
of an object around the grip point of a parallel gripper by allowing rotational
slip, while maintaining a desired wrist force profile. Our approach runs an
end-effector position controller and a gripper width controller concurrently in
a closed loop. The position controller maintains a desired force using vision
and wrist force. The gripper controller uses tactile sensing to keep the grip
firm enough to prevent translational slip, but loose enough to induce
rotational slip. Our sensor-based control approach relies on matching a desired
force profile derived from object dimensions and weight and vision-based
monitoring of the object pose. The gripper controller uses tactile sensors to
detect and prevent translational slip by tightening the grip when needed.
Experimental results where the robot was tasked with rotating cuboid objects 90
degrees show that the multi-modal pivoting approach was able to rotate the
objects without causing lift or slip, and was more energy-efficient compared to
using a single sensor modality and to pick-and-place. While our work
demonstrated the benefit of multi-modal sensing for the pivoting task, further
work is needed to generalize our approach to any given object.Comment: 8 pages, 8 figures, 2 table
Trends in the incidence of dementia in people with hypertension in the UK 2000 to 2021
INTRODUCTION: We investigated trends in the incidence of dementia in UK adults with hypertension. METHODS: Primary care electronic health records from IQVIA Medical Research Data UK, previously known as THIN, were used to identify 2,133,118 adults aged ≥40 years with hypertension over 2000 to 2021. The annual incidence rate and average annual percentage change in recorded dementia diagnoses were estimated and stratified by sex, 10-year age bands, Townsend deprivation quintiles and dementia subtype. RESULTS: The crude incidence rate of dementia in people with hypertension increased from 1.98 (95% confidence internal [CI] 1.89-2.07) per 1000 person-years at risk (PYAR) in 2000 to 5.29 per 1000 PYAR (95% CI 5.07-5.53) in 2021, corresponding to an average annual increase of 4.1% (95% CI 3.3-5.0). Those aged ≥80 years, the most economically deprived (Townsend = 5), and Alzheimer's disease subtype reported the highest incidence rate within their respective categories. DISCUSSION: The annual incidence rate of dementia in the hypertensive population has increased over the last 22 years. HIGHLIGHTS: New dementia diagnosis in the hypertensive population has increased over 22 years.The Alzheimer's disease subtype reported the highest incidence rate in people with hypertension.Difference in dementia incidence between hypertensive females and males has reduced.Difference in dementia incidence among deprivation categories has reduced in recent years
Typologies of change : gender integration in agriculture & food security research
This work was carried out with the aid of a grant from Canada’s International Development Research Centre (IDRC), and with financial support from the Government of Canada, provided through Global Affairs Canada (GAC).This synthesis of gender integration in the Canadian International Food Security Research Fund (CIFSRF) projects categorizes the different strategies used to address and integrate gender into development programming, and relates these strategies to gender outcomes of the projects. It draws from the eighteen agriculture and food security projects of CIFSRF Phase 2. It describes the research context of gender in agricultural research for development (AR4D); the research design, including the analytical framework of the synthesis; main findings; and recommendations. It includes a table of “Facilitating and constraining factors for gender integration in CIFSRF projects.
Lessons learned synthesis paper : gender integration and the Canadian International Food Security Research Fund
This work was carried out with the aid of a grant from Canada’s International Development Research Centre (IDRC), and with financial support from the Government of Canada, provided through Global Affairs Canada (GAC).CIFSRF projects aim to improve technology development and increase agricultural productivity, improve access to resources, markets and income along with a combination of objectives including cross-cutting themes of gender, environment and governance. This paper presents an overview of main findings on integrating gender mainstreaming in research and development programs. Women are differentiated in terms of their roles in agriculture and food security (AFS) as agents of change, primary or key clients, consumers, (central) beneficiaries, stakeholders and/or users. Social relations of gender are critical to actualize AFS’ ambition of a gender transformative approach to AFS research
India: Urban Finance and Governance Review Volume II: Case Study Annexes
The report makes an in depth analysis of what to expect of future urban population growth in cities across India. Cities play a critical role in India\u27s development. While its one billion-plus population is predominantly rural, over 300 million people live in urban areas. One-third of this population lives in 35 urban agglomerations or cities exceeding one million. Cities\u27 governments are responsible for delivering various public services, yet severe infrastructures shortages in water supply and sanitation, roads, transportation, housing and waste management, and inefficient management have resulted in poor quality services. These inadequate services and worsening environmental conditions affect the poor. Between 1950 and 2000 India\u27s urban population increased from 62 to 288 million. Already strained to provide services and quality of life to existing urban residents, cities will face tremendous challenges in expanding existing infrastructure and avoiding deterioration of living standards due to congestion, pollution, and lack of basic services. A doubling of the population over 30 years means that by 2030 there will be a second Mumbai, a second Calcutta, and a second Bangalore that must be fed, supplied with water, sanitation, electricity, give public and private transportation options; and where garbage must be disposed of. The report concludes by laying out a series of state and local actions over the short-medium and long-term to enhance fiscal sustainability and strengthening institutional capacity building of state and local governments
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