750 research outputs found
Performance evaluation of a chimney solar dryer for Habanero pepper (Capsicum chinense Jacq)
Habanero pepper (Capsicum chinense Jacq) is cultivated predominantly in the Volta, Central and Ashanti regions of Ghana and commonly utilised in most local dishes. Majority of consumers prefer the dried form of the pepper. However, farmers are usually confronted with the challenge of obtaining low-cost, locally fabricated dryers that can efficiently dry agricultural produce while mitigating quality and safety concerns. In this study, a model of the newly designed chimney solar dryer by the Horticulture Innovation laboratory of the University of California, Davis, in the United States of America, for crop drying in developing countries was constructed and its performance evaluated in comparison to open sun drying. Habanero pepper was used as a test crop. Subsequently, microbial analysis was carried out on the dried products. The mean chimney dryer temperature (46.4°C) was found to be higher than the ambient temperature (36.2°C). The relative humidity in the chimney solar dryer and the ambient ranged from 25% to 68% and 26% to 83%, respectively. During the period of the drying experiment, mean maximum solar insolation of 823.18 W/m2 was recorded at 11.30 am while a mean minimum solar insolation of 107.84 W/m2 was recorded at 4.30 pm. The solar-dried and sun-dried pepper recorded total drying time of 35 h and 55 h respectively. The mean performance coefficient of the chimney solar dryer was determined to be 1.21 which gives an indication of a high dryer performance. The mean yeasts and moulds counts of the solar-dried and sun-dried pepper were 4.30 x 104 cfu/g and 2.52 x 105 cfu/g, respectively. Also, the Staphylococcus aureus and Escherichia coli counts were <10 cfu/g for samples in both drying media. In conclusion, the chimney solar dryer was found to have performed better than open sun drying with shorter drying time and better qualityof the dried product.
Key words: chimney, habanero pepper, open sun drying, performance, quality, solar drye
Photoreactivation of total heterotrophic bacteria in bottled drinking water after inactivation with pulsed ultra-violet light
Bacteria which cause opportunistic infections such as Pseudomonas can self resuscitate incircumstances where effective UV disinfection is compromised and is exposed to sunlight. The study investigated the effect of sub-lethal doses of pulsed ultra-violet (PUV) light on total heterotrophic bacteria (THB) in three brands of bottled water packed in glass and plastic bottles and how photoreactivation and dark repair occurred. The effect of exposure time on photoreactivation of Escherichia coli and Pseudomonas aeruginosa after inactivation with PUV was also investigated. THB in brands 1, 2 and 3 were completely inactivated by 7, 3 and 5 pulses of UV light respectively. Light repair of THB varied in the three brands of bottled water due perhaps to differences in the ionic composition of the three brands. Brands 1, 2 and 3 having 0.4, 0.7 and 1.7 log units of repair. respectively. Evidence of dark repair was not significant. Photo-repair in E. coli and Pseudomonas aeruginosa increased gradually with continual exposure to irradiating light for a period after which there was a decrease, suggesting that for a particular bacterium and illuminating source, an optimum time of exposure exist during which maximum photo-repair occur
Antiferromagnetic Order Induced by an Applied Magnetic Field in a High-Temperature Superconductor
One view of the cuprate high-transition temperature (high-Tc) superconductors
is that they are conventional superconductors where the pairing occurs between
weakly interacting quasiparticles, which stand in one-to-one correspondence
with the electrons in ordinary metals - although the theory has to be pushed to
its limit. An alternative view is that the electrons organize into collective
textures (e.g. charge and spin stripes) which cannot be mapped onto the
electrons in ordinary metals. The phase diagram, a complex function of various
parameters (temperature, doping and magnetic field), should then be approached
using quantum field theories of objects such as textures and strings, rather
than point-like electrons. In an external magnetic field, magnetic flux
penetrates type-II superconductors via vortices, each carrying one flux
quantum. The vortices form lattices of resistive material embedded in the
non-resistive superconductor and can reveal the nature of the ground state -
e.g. a conventional metal or an ordered, striped phase - which would have
appeared had superconductivity not intervened. Knowledge of this ground state
clearly provides the most appropriate starting point for a pairing theory. Here
we report that for one high-Tc superconductor, the applied field which imposes
the vortex lattice, also induces antiferromagnetic order. Ordinary
quasiparticle pictures cannot account for the nearly field-independent
antiferromagnetic transition temperature revealed by our measurements
The Advancing Role of Nanocomposites in Cancer Diagnosis and Treatment
Vivian Andoh,1,* Dickson Kofi Wiredu Ocansey,2,3,* Hassan Naveed,1 Naijian Wang,4 Liang Chen,1 Keping Chen,1 Fei Mao2 1School of Life Sciences, Jiangsu University, Zhenjiang, People’s Republic of China; 2Department of Laboratory Medicine, Lianyungang Clinical College, Jiangsu University, Lianyungang, Jiangsu, People’s Republic of China; 3Directorate of University Health Services, University of Cape Coast, Cape Coast, Central Region, CC0959347, Ghana; 4Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, People’s Republic of China*The first two authors contributed equally to this workCorrespondence: Fei Mao, Department of Laboratory Medicine, Lianyungang Clinical College, Jiangsu University, Lianyungang, Jiangsu, 222006, People’s Republic of China, Tel/Fax +86 511 8503 8215, Email [email protected]: The relentless pursuit of effective cancer diagnosis and treatment strategies has led to the rapidly expanding field of nanotechnology, with a specific focus on nanocomposites. Nanocomposites, a combination of nanomaterials with diverse properties, have emerged as versatile tools in oncology, offering multifunctional platforms for targeted delivery, imaging, and therapeutic interventions. Nanocomposites exhibit great potential for early detection and accurate imaging in cancer diagnosis. Integrating various imaging modalities, such as magnetic resonance imaging (MRI), computed tomography (CT), and fluorescence imaging, into nanocomposites enables the development of contrast agents with enhanced sensitivity and specificity. Moreover, functionalizing nanocomposites with targeting ligands ensures selective accumulation in tumor tissues, facilitating precise imaging and diagnostic accuracy. On the therapeutic front, nanocomposites have revolutionized cancer treatment by overcoming traditional challenges associated with drug delivery. The controlled release of therapeutic agents from nanocomposite carriers enhances drug bioavailability, reduces systemic toxicity, and improves overall treatment efficacy. Additionally, the integration of stimuli-responsive components within nanocomposites enables site-specific drug release triggered by the unique microenvironment of the tumor. Despite the remarkable progress in the field, challenges such as biocompatibility, scalability, and long-term safety profiles remain. This article provides a comprehensive overview of recent developments, challenges, and prospects, emphasizing the transformative potential of nanocomposites in revolutionizing the landscape of cancer diagnostics and therapeutics. In Conclusion, integrating nanocomposites in cancer diagnosis and treatment heralds a new era for precision medicine. Keywords: nanocomposites, cancer, diagnosis, therapy, nanoparticles, theranosti
The Rho GDI Rdi1 regulates Rho GTPases by distinct mechanisms
© 2008 by The American Society for Cell Biology. Under the License and Publishing Agreement, authors grant to the general public, effective two months after publication of (i.e.,. the appearance of) the edited manuscript in an online issue of MBoC, the nonexclusive right to copy, distribute, or display the manuscript subject to the terms of the Creative Commons–Noncommercial–Share Alike 3.0 Unported license (http://creativecommons.org/licenses/by-nc-sa/3.0).The small guanosine triphosphate (GTP)-binding proteins of the Rho family are implicated in various cell functions, including establishment and maintenance of cell polarity. Activity of Rho guanosine triphosphatases (GTPases) is not only regulated by guanine nucleotide exchange factors and GTPase-activating proteins but also by guanine nucleotide dissociation inhibitors (GDIs). These proteins have the ability to extract Rho proteins from membranes and keep them in an inactive cytosolic complex. Here, we show that Rdi1, the sole Rho GDI of the yeast Saccharomyces cerevisiae, contributes to pseudohyphal growth and mitotic exit. Rdi1 interacts only with Cdc42, Rho1, and Rho4, and it regulates these Rho GTPases by distinct mechanisms. Binding between Rdi1 and Cdc42 as well as Rho1 is modulated by the Cdc42 effector and p21-activated kinase Cla4. After membrane extraction mediated by Rdi1, Rho4 is degraded by a novel mechanism, which includes the glycogen synthase kinase 3β homologue Ygk3, vacuolar proteases, and the proteasome. Together, these results indicate that Rdi1 uses distinct modes of regulation for different Rho GTPases.Deutsche Forschungsgemeinschaf
IL-22 mediates goblet cell hyperplasia and worm expulsion in intestinal helminth infection.
Type 2 immune responses are essential in protection against intestinal helminth infections. In this study we show that IL-22, a cytokine important in defence against bacterial infections in the intestinal tract, is also a critical mediator of anti-helminth immunity. After infection with Nippostrongylus brasiliensis, a rodent hookworm, IL-22-deficient mice showed impaired worm expulsion despite normal levels of type 2 cytokine production. The impaired worm expulsion correlated with reduced goblet cell hyperplasia and reduced expression of goblet cell markers. We further confirmed our findings in a second nematode model, the murine whipworm Trichuris muris. T.muris infected IL-22-deficient mice had a similar phenotype to that seen in N.brasiliensis infection, with impaired worm expulsion and reduced goblet cell hyperplasia. Ex vivo and in vitro analysis demonstrated that IL-22 is able to directly induce the expression of several goblet cell markers, including mucins. Taken together, our findings reveal that IL-22 plays an important role in goblet cell activation, and thus, a key role in anti-helminth immunity
SPARC is expressed in renal interstitial fibrosis and in renal vascular injury
SPARC is expressed in renal interstitial fibrosis and in renal vascular injury. Tubulointerstitial inflammation and fibrosis are critical determinants for renal function and prognosis in a variety of human nephropathies. Yet, the pathophysiology of the injury remains obscure. We investigated the expression of SPARC (secreted protein acidic and rich in cysteine) by immunohistochemistry and in situ hybridization in experimental models characterized by tubulointerstitial fibrosis and matrix expansion in rats. SPARC is a secreted glycoprotein that has been demonstrated to affect cellular interaction with matrix proteins, modulate cell proliferation, bind to and/or inhibit growth factors such as PDGF and bFGF, and regulate angiogenesis. Interstitial expression of SPARC was most prominent in passive Heyman nephritis (PHN), chronic cyclosporine A (CsA) nephropathy, and the remnant kidney model and, to a lesser extent, in angiotensin II (Ang II)-infused animals. SPARC protein and mRNA were substantially increased at sites of tubulointerstitial fibrosis/matrix expansion. In the PHN model, SPARC protein was expressed by interstitial fibroblasts that also produced α-smooth muscle actin (“myofibroblasts”) and correlated both temporally (r = 0.97) and spatially with sites of type I collagen deposition. Interstitial cell proliferation preceded the development of interstitial fibrosis, and maximal SPARC expression (d15) coincided with the initial decline in interstitial proliferation. In the Ang II-infusion model, which is characterized by arteriolopathy and tubulointerstitial injury, an increase in SPARC protein and mRNA was also seen in injured blood vessels. SPARC was shown to be expressed by vascular smooth muscle cells and also by cells in the adventitia of hypertrophied arteries. In summary, SPARC was transiently expressed by interstitial fibroblasts at sites of tubulointerstitial injury and fibrosis, and by smooth muscle cells and cells in the adventitia of injured arteries in the Ang II-model. In addition to its proposed role in extracellular matrix deposition, the antiproliferative properties of SPARC might contribute to the resolution of interstitial fibroblast proliferation in the PHN model
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