scholarly journals ASSAY AND GRAPHITE FURNACE- ATOMIC ABSORBANCE SPECTROMETRY ACCURACY FOR PALLADIUM CONTENT ANALYSIS

2021 ◽  
Vol 15 (2) ◽  
Author(s):  
Ronaldo Irzon ◽  
Kurnia
Keyword(s):  
Ultramafic Rock ◽  
Graphite Furnace ◽  
High Sensitivity ◽  
Modern Technology ◽  
Stream Sediment ◽  
Platinum Group Metals ◽  
Almost All ◽  
House Standard ◽  
Palladium Content ◽  
Reference Samples

Palladium is a member of the expensive Platinum Group Metals as it is indispensable for various applications of modern technology. Due to the very small number of these elements in nature, high-sensitivity analytical methods and devices are required for accurate PGM measurement. The current study aims to determine the accuracy level of the Graphite Furnace-Atomic Absorbance Spectrometry device for palladium analysis after pre-concentration through the assaying process. The studied samples were two in-house standard reference samples with stream sediment and ultramafic rock matrices. Due to the lack of certified reference material containing certain palladium compositions, the degree of accuracy was tested by the spiking method. The detection limit for Pd in this study was 11.79 ppb. Pd content in the stream sediment (17 ppb) is much lower than of the ultramafic sample (290 ppb), implying PGM association to ultramafic rock naturally. Almost all measurements have good accuracy according to spike recovery between 80-120%. Inaccurate addition process and inappropriate calibration range most probably lead to inaccuracy.

Mechanism of anteroposterior axis specification in vertebrates. Lessons from the amphibians

Development ◽  
1992 ◽  
Vol 114 (2) ◽  
pp. 285-302 ◽  
Author(s):  
J.M. Slack ◽  
D. Tannahill
Keyword(s):  
Molecular Markers ◽  
Expression Patterns ◽  
Signal Transduction Pathway ◽  
Homeobox Gene ◽  
Neural Induction ◽  
High Sensitivity ◽  
Neural Plate ◽  
Mesoderm Induction ◽  
Inducing Factors ◽  
Almost All

Interest in the problem of anteroposterior specification has quickened because of our near understanding of the mechanism in Drosophila and because of the homology of Antennapedia-like homeobox gene expression patterns in Drosophila and vertebrates. But vertebrates differ from Drosophila because of morphogenetic movements and interactions between tissue layers, both intimately associated with anteroposterior specification. The purpose of this article is to review classical findings and to enquire how far these have been confirmed, refuted or extended by modern work. The “pre-molecular” work suggests that there are several steps to the process: (i) Formation of anteroposterior pattern in mesoderm during gastrulation with posterior dominance. (ii) Regional specific induction of ectoderm to form neural plate. (iii) Reciprocal interactions from neural plate to mesoderm. (iv) Interactions within neural plate with posterior dominance. Unfortunately, almost all the observable markers are in the CNS rather than in the mesoderm where the initial specification is thought to occur. This has meant that the specification of the mesoderm has been assayed indirectly by transplantation methods such as the Einsteckung. New molecular markers now supplement morphological ones but they are still mainly in the CNS and not the mesoderm. A particular interest attaches to the genes of the Antp-like HOX clusters since these may not only be markers but actual coding factors for anteroposterior levels. We have a new understanding of mesoderm induction based on the discovery of activins and fibroblast growth factors (FGFs) as candidate inducing factors. These factors have later consequences for anteroposterior pattern with activin tending to induce anterior, and FGF posterior structures. Recent work on neural induction has implicated cAMP and protein kinase C (PKC) as elements of the signal transduction pathway and has provided new evidence for the importance of tangential neural induction. The regional specificity of neural induction has been reinvestigated using molecular markers and provides conclusions rather similar to the classical work. Defects in the axial pattern may be produced by retinoic acid but it remains unclear whether its effects are truly coordinate ones or are concentrated in certain regions of high sensitivity. In general the molecular studies have supported and reinforced the “pre-molecular ones”. Important questions still remain: (i) How much pattern is there in the mesoderm (how many states?) (ii) How is this pattern generated by the invaginating organizer? (iii) Is there one-to-one transmission of codings to the neural plate? (iv) What is the nature of the interactions within the neural plate? (v) Are the HOX cluster genes really the anteroposterior codings?

scholarly journals Possibilities Of Application Of New Innovative Technologies In Football

2021 ◽  
Vol 03 (01) ◽  
pp. 404-409
Author(s):  
Baxtiyor Abdumurodovich Sultanov ◽  
Keyword(s):  
Modern Technology ◽  
Innovative Technologies ◽  
The World ◽  
Technological Developments ◽  
Almost All

Modern technology is developing at an amazing pace in almost all areas of our lives. Most likely, it was inevitable that technological developments would also quickly become commonplace in the world of sports. Some of these technologies are at the heart of football today. Companies from all over the world are coming up with more and more new inventions designed to help teams prepare for the competition, improve training regimes and, finally, become a factor for winning matches.

scholarly journals Detection of Coccidioides posadasii in a patient with meningitis using metagenomic next-generation sequencing: a case report

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuqiao Mao ◽  
Xia Li ◽  
Haibo Lou ◽  
Xiaoyu Shang ◽  
Yanjun Mai ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Los Angeles ◽  
Systemic Infection ◽  
High Sensitivity ◽  
Pathological Examination ◽  
Next Generation ◽  
Coccidioides Posadasii ◽  
Dimorphic Fungi ◽  
Almost All ◽  
Generation Sequencing

Abstract Background Coccidioidomycosis is a systemic infection caused by dimorphic fungi Coccidioides spp. endemic to Southwestern United States and Central and South America. A history of residence and travel in these areas is essential for the diagnostic of coccidioidomycosis, which has highly variable symptoms ranging from asymptomatic to severe, disseminated infection, and even death. Immunocompromised patients of coccidioidomycosis experience a high risk of dissemination, chronic infection, and mortality. Meningitis is one of the most deleterious coccidioidomycosis and can cause various life-threatening complications. Case presentation Here we report a case of Coccidioides posadasii meningitis in a 49-year-old female who returned to China after one and a half years residence in Los Angeles, USA. The repeated routine cultures using CSF for bacteria or fungi were all negative. To hunt for an infectious etiology, the state-of-the-art technology metagenomic next-generation sequencing (mNGS) was then utilized, suggesting Coccidioides posadasii. Organizational pathological examination and polymerase-chain-reaction (PCR) results subsequently confirmed the mNGS detection. Conclusion To our knowledge, cases for coccidioidal meningitis have been rarely reported in China. While global travelling may spread this disease across continents and make the diagnosis more difficult. mNGS can detect almost all known pathogens with high sensitivity and specificity, especially for uncommon pathogen, such as Coccidioides posadasii in China.

The All-Powerful NIMBY

2000 ◽  
Author(s):  
Hans Tammemagi
Keyword(s):  
United States ◽  
New York ◽  
Waste Management ◽  
New York State ◽  
The United States ◽  
Modern Technology ◽  
Strong Trend ◽  
The People ◽  
Transfer Stations ◽  
Almost All

Our society has reached a frustrating impasse: everyone wants consumer goods, but nobody wants the associated waste. In all levels of society from the grass-roots to the highest level of politics, enormous public opposition has developed to siting landfills, incinerators, or transfer stations. With complex judicial and political systems that promote empowerment of the people, it has become common for opposition groups to delay or halt altogether the introduction of new waste management facilities. The NIMBY—Not In My Back Yard—syndrome has become a powerful force. This chapter explores the process by which the sites for landfills and related waste facilities are selected. This fascinating topic goes far beyond technical issues: it provides insight into human behavior and the ways political decisions are made. An understanding of the NIMBY phenomenon is essential for anyone who wishes to pursue a career in waste management. In some regions there is already a crisis. In New Jersey, for example, the number of landfills has dropped from more than 300 to about a dozen in the past two decades. As a result, more than half of New Jersey’s municipal solid waste must be exported to other states. In New York state, 298 landfills were closed and only 6 new ones opened in the decade since 1982. The same story is unfolding in almost all jurisdictions in North America; the number of landfills in the United States dwindled from 20,000 in 1979 to about 5,300 in 1993 (Miller, 1997). There is a very strong trend toward fewer—but much bigger—landfills. In the United States it is estimated that 8% of the existing landfills handle 75% of the country’s garbage. As the number of landfills decreases, their heights grow, casting dark shadows across the land. There is no doubt that new landfills are safer than old ones: they are generally better sited and incorporate better engineering and modern technology such as liners, covers, and leachate and gas extraction systems. However, people still do not want them next door. Thus, the few new landfills that are being developed are getting larger and larger; the megadump is the trend of the future.

scholarly journals Complementary Bursts, Coronal Inhomogeneities and New Microscopic Spectral Features of Solar Bursts in Type IV Bursts

1980 ◽  
Vol 86 ◽  
pp. 269-271
Author(s):  
H. S. Sawant ◽  
R. V. Bhonsle ◽  
S. S. Degaonkar ◽  
T. Takakura
Keyword(s):  
High Frequency ◽  
High Sensitivity ◽  
Line Of Sight ◽  
Spectral Features ◽  
Frequency Range ◽  
Type Iv ◽  
Linear Extent ◽  
Solar Bursts ◽  
Almost All ◽  
Density Irregularity

Complementary bursts (C.B's) have been observed in the decametric range during noise storms and/or type IV activity. These bursts essentially consist of two components, each component having a duration ~ 1 second. The first component shows weak emission or emission gap over a certain frequency range. The second component is observed after a certain delay. If the bursts are assumed to be generated at the fundamental, and if the radiation corresponding to the gap propagates through an electron density irregularity located close to the source along the line of sight, whose cross-section is less than the linear extent of the source, then almost all properties of the C.B.'s can be explained. High sensitivity, and high frequency and time resolution spectra of type IV bursts at 137 MHz revealed new microscopic spectral features displaying “wave-like” and “fork-like” shapes.

Comparison of Antimony Determination Methods in Drinking Water

2013 ◽  
Vol 706-708 ◽  
pp. 478-482
Author(s):  
Nan Chen ◽  
Yong Sheng Shi ◽  
Meng Zhao ◽  
Meng Ru Xuan
Keyword(s):  
Inductively Coupled Plasma ◽  
Graphite Furnace ◽  
Low Cost ◽  
Water Environment ◽  
Hydride Generation ◽  
High Sensitivity ◽  
Atomic Fluorescence Spectrometry ◽  
Element Analysis ◽  
Inductively Coupled ◽  
Low Sensitivity

Antimony distributes widely in the environment. And antimony pollution in the water environment is becoming serious. How to detect the content of the antimony correctly and effectively is very important. Graphite furnace atomic absorption method is simple, but low sensitivity; hydride generation atomic fluorescence spectrometry, low cost, good reproducibility, but is harmful to the introduction of substances; inductively coupled plasma mass spectrometry for simultaneous multi-element analysis, high sensitivity, but the operation is cumbersome; inductively coupled plasma spectrometry has low detection limit, high accuracy, but the equipment is expensive, and cost of analysis is high.

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