Enhanced differentiation of human embryonic stem cells towards definitive endoderm on ultrahigh aspect ratio nanopillars

Differentiation of human embryonic stem cells is widely studied as a potential unlimited source for cell replacement therapy to treat degenerative diseases such as diabetes. The directed differentiation of human embryonic stem cells relies mainly on soluble factors. Although, some studies have highlighted that the properties of the physical environment, such as substrate stiffness, affect cellular behavior. Here, mass-produced, injection molded polycarbonate nanopillars are presented, where the surface mechanical properties, i.e., stiffness, can be controlled by the geometric design of the ultrahigh aspect ratio nanopillars (stiffness can be reduced by 25.0003). It is found that tall nanopillars, yielding softer surfaces, significantly enhance the induction of definitive endoderm cells from pluripotent human embryonic stem cells, resulting in more consistent differentiation of a pure population compared to planar control. By contrast, further differentiation toward the pancreatic ­endoderm is less successful on “soft” pillars when compared to “stiff” pillars or control, indicating differential cues during the different stages of differentiation. To accompany the mechanical properties of the nanopillars, the concept of surface shear modulus is introduced to describe the characteristics of engineered elastic surfaces through micro or nanopatterning. This provides a framework whereby comparisons can be drawn between such materials and bulk elastomeric materials

Reshaping Global Change Science for the 21st Century: Young Scientists’ Perspectives

Humanity is facing unprecedented environmental, social, and economic challenges. We ask what the role of the global science community should be in tackling these challenges. Increased awareness of the social context in which science is being produced; acceptance of the importance of controversy; and reflection around normative assumptions underlying research are needed. To help solve humanity’s grand challenges scientists need to move towards a transdisciplinary view of science where knowledge emerges from a collaborative environment and where young scientists are trained to work across disciplinary boundaries and engage with policy communities

Interconnection blocks: a method for providing reusable, rapid, multiple, aligned and planar microfluidic interconnections

Abstract In this paper a method is presented for creating 'interconnection blocks' that are re-usable and provide multiple, aligned and planar microfluidic interconnections. Interconnection blocks made from polydimethylsiloxane allow rapid testing of microfluidic chips and unobstructed microfluidic observation. The interconnection block method is scalable, flexible and supports high interconnection density. The average pressure limit of the interconnection block was near 5.5 bar and all individual results were well above the 2 bar threshold considered applicable to most microfluidic applications

Controlling fluid flow to improve cell seeding uniformity

Standard methods for seeding monolayer cell cultures in a multiwell plate or dish do not uniformly distribute cells on the surface. With traditional methods, users find aggregation around the circumference, in the centre, or a combination of the two. This variation is introduced due to the macro scale flow of the cell seeding suspension, and movement of the dish before cells can settle and attach to the surface. Reproducibility between labs, users, and experiments is hampered by this variability in cell seeding. We present a simple method for uniform and user-independent the cell seeding using an easily produced uniform cell seeder (UCS) device. This allows precise control of cell density in a reproducible manner. By containing the cell seeding suspension in a defined volume above the culture surface with the UCS, fluctuations in cell density are minimised. Seeding accuracy, as defined by the actual cell density versus the target seeding density is improved dramatically across users with various levels of expertise. We go on to demonstrate the impact of local variation in cell density on the lineage commitment of human embryonic stem cells (hESCs) towards pancreatic endoderm (PE). Variations in the differentiation profile of cells across a culture well closely mirror variations in cell density introduced by seeding method–with the UCS correcting variations in differentiation efficiency. The UCS device provides a simple and reproducible method for uniform seeding across multiple culture systems

Microfludic Device for Creating Ionic Strength Gradients over DNA Microarrays for Efficient DNA Melting Studies and Assay Development

The development of DNA microarray assays is hampered by two important aspects: processing of the microarrays is done under a single stringency condition, and characteristics such as melting temperature are difficult to predict for immobilized probes. A technical solution to these limitations is to use a thermal gradient and information from melting curves, for instance to score genotypes. However, application of temperature gradients normally requires complicated equipment, and the size of the arrays that can be investigated is restricted due to heat dissipation. Here we present a simple microfluidic device that creates a gradient comprising zones of defined ionic strength over a glass slide, in which each zone corresponds to a subarray. Using this device, we demonstrated that ionic strength gradients function in a similar fashion as corresponding thermal gradients in assay development. More specifically, we noted that (i) the two stringency modulators generated melting curves that could be compared, (ii) both led to increased assay robustness, and (iii) both were associated with difficulties in genotyping the same mutation. These findings demonstrate that ionic strength stringency buffers can be used instead of thermal gradients. Given the flexibility of design of ionic gradients, these can be created over all types of arrays, and encompass an attractive alternative to temperature gradients, avoiding curtailment of the size or spacing of subarrays on slides associated with temperature gradients

Re-shaping Sustainability Science for the 21st Century: Young Scientists’ Perspectives

Humanity is facing unprecedented environmental, social and economic challenges. We ask what the role of the sustainability science community should be in tackling these challenges, focusing particularly on young scientists’ perspectives on the issue. On the basis of a questionnaire and a workshop with young scientists, we identify four major challenges facing humanity and develop three guidelines for sustainability science that seeks to address them. Results show that to help address humanity’s grand challenges, sustainability scientists need to move towards a trans-disciplinary system view of science and sustainability science problems. According to this view knowledge emerges from a collaborative and transdisciplinary environment and young scientists are trained to work across disciplinary boundaries and engage with policy communities

ANALISIS HUBUNGAN DUKUNGAN PSIKOSOSIAL DENGAN KEPUTUSAN MEMILIH METODE KONTRASEPSI JANGKA PANJANG DI WILAYAH KAMPUNG KB KOTA PADANG TAHUN 2019

Angka Kematian Ibu (AKI) Indonesia saat ini masih dalam kategori tinggi. Salah satu strategi menurunkan AKI adalah program KB. Program KB berkontribusi menurunkan 32% dari seluruh kematian ibu dengan meningkatkan cakupan Metode Kontrasepsi Jangka Panjang (MKJP) yang saat ini capaiannya hanya 17,45%. Penggunaan MKJP oleh Pasangan Usia Subur (PUS) dipengaruhi oleh banyak faktor salah satunya dukungan psikososial. Penelitian ini bertujuan menganalisis hubungan antara dukungan psikososial (emosional, informasional, instrumental, penghargaan) dengan keputusan memilih MKJP di Kampung KB. Penelitian ini menggunakan desain mixed methods dengan pendekatan sequential explanatory terhadap 100 responden akseptor KB dan Informan penelitian yang ditentukan dengan teknik simple random sampling dan snowball sampling. Pengumpulan data diperoleh dari kuesioner, wawancara mendalam, observasi dan studi dokumentasi. Analisis data yang digunakan adalah uji chi-square, regresi logistic dan constant comparative method. Hasil penelitian menunjukkan terdapat hubungan signifikan antara dukungan emosional dengan keputusan memilih KB MKJP di Kampung KB dengan nilai ρ 0,028, begitu juga dengan dukungan instrumental (ρ 0,019) dan dukungan penghargaan (ρ 0,000). Sementara, dukungan informasional tidak berhubungan karena memiliki nilai ρ>0,05. Faktor yang paling dominan adalah dukungan penghargaan dengan nilai ood rasio (OR) sebesar 5,000. Faktor lain yang mempengaruhi keputusan memilih MKJP di Kampung KB adalah ketakutan pasangan dan orang tua terhadap efek samping metode MKJP, kompetensi provider, prosedur pencatatan dan pelaporan, kualitas pelayanan KB, budaya, persepsi negatif terhadap MKJP serta belum adanya target sasaran alat kontrasepsi. Dukungan penghargaan merupakan faktor dominan yang mempengaruhi keputusan PUS memilih KB MKJP di Kampung KB. PUS yang memperoleh dukungan penghargaan dari lingkungan akan 5,000 kali berpeluang memutuskan memilih MKJP. Kata kunci : Dukungan psikososial, Pasangan Usia Subur, MKJP, Kampung K