484 research outputs found
Regeneration ability and genetic transformation of root type chicory (Cichorium intybus var. sativum)
To develop an efficient protocol for shoot regeneration of root chicory (Cichorium intybus var. sativum), some factors, including different concentrations of plant growth regulators in Murashige and Skoog (MS) medium, type of explants and genotypes were evaluated. Initiation of callusing were best achieved in MS medium supplemented with 1-naphthaleneacetic acid (NAA) (0.1 mg l-1) plus 6-Benzylaminopurine (6-BAP) (1 mg l-1), indole-3-acetic acid (IAA) (0.01 mg l-1) plus 6-BAP (1.0 mg l-1), and IAA (0.5 mg l-1) plus (0.5 mg l-1) 6-BAP combinations on leaf and cotyledon explants. Explant-derived calli were able to produce multiple adventitious shoots in MS medium containing IAA (0.5 mg l-1) plus 6-BAP (0.5 mg l-1). MS medium containing indole-3-butylric acid IBA (1 mgl-1) efficiently induced rooting on elongated shoots. Various responses to the number of generated shoots were observed when regeneration abilities of different chicory cultivars were examined. Among root and “Witloof” cultivars, ‘Melci’ and ‘Hera’ belong to the root cultivars and exhibited higher shoot regeneration ability. Using the optimized regeneration method, genetic transformation of ‘Melci’ with Agrobacterium tumefaciens strain C58C1 RifR (pGV2260) (pTJK136) was successfully carried out. Histochemical GUS assay, polymerase chain reaction (PCR) and reverse transcription-polymerase chain reaction (RT-PCR) analysis of putative transformed plants confirmed successful integration of the T-DNA into the chicory genome. Expression of the neomycine phosphotransferase (NPTII) in the regenerated plants was also shown by well-developed roots on root inducing medium containing 100 mg l-1 kanamycin. This simple, efficient and reproducible protocol could be useful for inducing somaclonal variation and genetic modification of root chicory cultivars to broaden genetic variation and transferring of important genes
Frequency effect on streaming phenomenon induced by Rayleigh surface acoustic wave in microdroplets
Acoustic streaming of ink particles inside a water microdroplet generated by a surface acoustic wave(SAW) has been studied numerically using a finite volume numerical method and these results have been verified using experimental measurements. Effects of SAW excitation frequency, droplet volume, and radio-frequency (RF) power are investigated, and it has been shown that SAW excitation frequency influences the SAWattenuation length, lSAW , and hence the acoustic energy absorbed by liquid. It has also been observed that an increase of excitation frequency generally enhances the SAW streaming behavior. However, when the frequency exceeds a critical value that depends on the RF power applied to the SAW device, weaker acoustic streaming is observed resulting in less effective acoustic mixing inside the droplet. This critical value is characterised by a dimensionless ratio of droplet radius to SAWattenuation length, i.e., Rd/lSAW . With a mean value of Rd/lSAW ≈ 1, a fast and efficient mixing can be induced, even at the lowest RF power of 0.05 mW studied in this paper. On the other hand, for the Rd/lSAW ratios much larger than ∼1, significant decreases in streaming velocities were observed, resulting in a transition from regular (strong) to irregular (weak) mixing/flow. This is attributed to an increased absorption rate of acoustic wave energy that leaks into the liquid, resulting in a reduction of the acoustic energy radiated away from the SAW interaction region towards the droplet free surface. It has been demonstrated in this study that a fast and efficient mixing process with a smaller RF power could be achieved if the ratio of Rd/lSAW ≤ 1 in the SAW-droplet based microfluidics
Financing an early stage biotechnology company in Canada
1 online resource (vi, 39 p.) : col. ill.Immunovaccine, a young Canadian biotechnology firm, for many years relied on several methods to finance its operations to date, including investment from angels, various forms of government grants and a reverse takeover (RTO) on the Toronto venture stock exchange (TSXV) to access the public markets. Currently the firm which has very favorable and expanding prospects is finding it difficult to raise significant funds in Canada. Investor interest is focused on natural resources stocks and the company, being listed on the TSXV, has limited access to US private equity and venture funds who view the stock as unpredictable and illiquid. Big pharma remains interested in more advanced products and the limited access to US public markets is crippling. The provincial government lends its support in the form of a repayable loan. In the end, the company turns to private investors in the UK and is over-subscribed in a private placement that extends its runway to 2015 while it contemplates its next move. This case outlines the difficulties experienced by an early stage biotechnology firm in Canada looking for capital to finance its long term requirements. Differences in the financing environment in Canada and the US and a roadmap to US capital markets are discussed. This is not intended to illustrate either effective or ineffective handling of a managerial situation. It is meant to provide a reasonable account of events and situations for the purposes of stimulating discussion
Regeneration ability and genetic transformation of root type chicory (Cichorium intybus var. sativum)
To develop an efficient protocol for shoot regeneration of root chicory (Cichorium intybus var. sativum), some factors, including different concentrations of plant growth regulators in Murashige and Skoog (MS) medium, type of explants and genotypes were evaluated. Initiation of callusing were best achieved in MS medium supplemented with 1-naphthaleneacetic acid (NAA) (0.1 mg l-1) plus 6-Benzylaminopurine (6-BAP) (1 mg l-1), indole-3-acetic acid (IAA) (0.01 mg l-1) plus 6-BAP (1.0 mg l-1), and IAA (0.5 mg l-1) plus (0.5 mg l-1) 6-BAP combinations on leaf and cotyledon explants. Explant-derived calli were able to produce multiple adventitious shoots in MS medium containing IAA (0.5 mg l-1) plus 6-BAP (0.5 mg l-1). MS medium containing indole-3-butylric acid IBA (1 mgl-1) efficiently induced rooting on elongated shoots. Various responses to the number of generated shoots were observed when regeneration abilities of different chicory cultivars were examined. Among root and “Witloof” cultivars, ‘Melci’ and ‘Hera’ belong to the root cultivars and exhibited higher shoot regeneration ability. Using the optimized regeneration method, genetic transformation of ‘Melci’ with Agrobacterium tumefaciens strain C58C1 RifR (pGV2260) (pTJK136) was successfully carried out. Histochemical GUS assay, polymerase chain reaction (PCR) and reverse transcription-polymerase chain reaction (RT-PCR) analysis of putative transformed plants confirmed successful integration of the T-DNA into the chicory genome. Expression of the neomycine phosphotransferase (NPTII) in the regenerated plants was also shown by well-developed roots on root inducing medium containing 100 mg l-1 kanamycin. This simple, efficient and reproducible protocol could be useful for inducing somaclonal variation and genetic modification of root chicory cultivars to broaden genetic variation and transferring of important genes.Keywords: Chicory, regeneration, transformation, 1-Naphthaleneacetic acid (NAA), indole-3-acetic acid (IAA), 6-Benzylaminopurine (6-BAP
In-line monitoring of electrolytes and urea during continuous renal replacement therapy
The individualization of dialysis treatment using a customized dialysate composition usually requires a continuous measurement of electrolytes and urea in blood. The current practices are spot measurements of blood samples either with blood gas analyzers or in the laboratory, involving considerable personnel effort. Furthermore, the measured values are time delayed and not available in a continuous fashion. In this paper we investigate an in-line concept for continuous monitoring of important blood parameters such as sodium, potassium, calcium and urea concentrations in blood serum using ion-selective electrodes. This concept is evaluated in a preclinical study with human packed red blood cells as a test medium over a period of 7 h. It has been shown that the electrolytes can be well monitored. In addition, we present first measurements with ion-sensitive field-effect transistors in a miniaturized sensor assembly. Therefore, new low-cost electronics for such ion-sensitive field-effect transistors have been developed
Monitoring clone dynamics and reversibility in clonal haematopoiesis and myelodysplastic neoplasm associated with PARP inhibitor therapy-a role for early monitoring and intervention
The Australasian Students' Surgical Association: organizational growth amidst the challenges of the COVID-19 pandemic
[Extract] Student surgical societies play an important role in complementing university medical curricula in the delivery of surgical education, fostering interest in surgery and facilitating networking and career opportunities.1 The Australasian Students' Surgical Association (ASSA) was established in 2015 as a not-for-profit student-run organization aiming to unite the 26 student surgical societies across Australia and New Zealand.2 Through in-person conferences, Sydney-based leadership seminars and surgical workshops, the ASSA has successfully achieved its vision to support surgical education, foster student interest in surgery, and create a culture of collaboration amongst surgical societies. As the COVID-19 pandemic presented a variety of unforeseen challenges to the medical profession, student organizations across the world were required to adapt to the content and delivery of activities.3 The pandemic posed significant challenges for the ASSA to continue promoting a pre-vocational interest in surgery for Australian and New Zealand medical students and required innovative strategies to continue delivering educational opportunities. This need to adopt alternative approaches provided an opportunity for innovation and embracing technology to overcome COVID-19 related restrictions to continue achieving the goals for ASSA
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