2,063 research outputs found

    One-pot radioiodination of aryl amines via stable diazonium salts: preparation of 125I-imaging agents

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    An operationally simple, one-pot, two-step tandem procedure that allows the incorporation of radioactive iodine into aryl amines via stable diazonium salts is described. The mild conditions are tolerant of various functional groups and substitution patterns, allowing late-stage, rapid access to a wide range of 125I-labelled aryl compounds and SPECT radiotracers

    Ebola virus VP30 and nucleoprotein interactions modulate viral RNA synthesis

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    AbstractEbola virus (EBOV) is an enveloped negative-sense RNA virus that causes sporadic outbreaks with high case fatality rates. Ebola viral protein 30 (eVP30) plays a critical role in EBOV transcription initiation at the nucleoprotein (eNP) gene, with additional roles in the replication cycle such as viral assembly. However, the mechanistic basis for how eVP30 functions during the virus replication cycle is currently unclear. Here we define a key interaction between eVP30 and a peptide derived from eNP that is important to facilitate interactions leading to the recognition of the RNA template. We present crystal structures of the eVP30 C-terminus in complex with this eNP peptide. Functional analyses of the eVP30–eNP interface identify residues that are critical for viral RNA synthesis. Altogether, these results support a model where the eVP30–eNP interaction plays a critical role in transcription initiation and provides a novel target for the development of antiviral therapy.</jats:p

    Impact of Climate Variations on Soybean Yield in Eastern Arkansas: 1960-2014

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    Climate is the major factor affecting crop production; therefore, various agro-meteorological indicators have been frequently used to evaluate the impact of climate on crop production. In this study, we examined the temporal variations of agrometeorological indicators (growing degree days, total precipitation, dry spells and drought indices) during 1960-2014 and their impact on soybean yields in East Arkansas. Results show an increasing trend in growing degree days (GDDs) and dry spells, though the total precipitation during the soybean growing season remained nearly unchanged during the study period. Generally, GDDs and dry spells show a strong correlation with yields. We also evaluated drought variability based on different drought indices, including the Palmer Drought Severity Index (PDSI), the Standardized Precipitation Index (SPI) and the Standardized Precipitation-Evapotranspiration Index (SPEI). The drought indices are all negatively correlated to soybean yields. Overall, the one month SPEI showed the strongest impact on yields. After regression analysis, Dry spells and Total precipitation were the only significant factors in the General Linear Model (GLM)

    Analysis by polymerase chain reaction of the physical state of human papillomavirus type 16 DNA in cervical preneoplastic and neoplastic lesions

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    Integration of human papillomavirus (HPV) DNA into the host cell genome is believed to be essential for malignant progression. However unambiguous detection of the physical state of HPV is a difficult and time-consuming procedure. To resolve this issue a simple, rapid and highly sensitive technique of polymerase chain reaction (PCR) has been utilized for detecting the physical state of HPV-16 DNA. Investigations were carried out in 122 cervical specimens comprising the whole spectrum of cervical lesions starting from cervical dysplasia to invasive carcinoma including HPV-16-positive normal controls. A pair of oligonucleotide primers specific to the E2 open reading frame, which is often deleted or disrupted following HPV integration, was used for the study. Distinction between episomal and integrated forms of viral DNA was accomplished by detecting amplification of the E2-specific fragment (1139 bp) in the PCR product. The PCR results were compared with those obtained by the conventional methods of Southern blotting, two-dimensional gel electrophoresis and chromosomal in situ hybridization; a high degree of agreement was observed between the methods. The findings indicate that although integrated forms of HPV-16 DNA were detected in more than 70% of cervical cancer specimens, integration was less frequent (23%) in severe dysplasia and carcinoma in situ. Only 2.5% of cases showed both episomal and integrated forms of HPV-16 DNA. The difference between episomal and integrated forms was statistically significant (P &lt; 0.01). The absence of integration in about 30% of cancer cases suggests that integration of HPV may not be necessary for malignant progression and alternative mechanism(s) of malignant transformation may occur without HPV integration. The PCR test thus provides an effective complement to Southern blotting and two-dimensional gel electrophoresis for accurate detection of the integration of HPV DNA

    Blow Molding Process Automation using Data-Driven Tools

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    With the increasing demand for goods in today’s world with its ever-increasing population, industries are driven to boost their production rate. This makes issues of process optimization, maintenance, and quality control difficult to be carried out manually. Furthermore, most industrial sectors have a plethora of data acquired every day with very little knowledge and ideas to handle it most effectively. Motivated by these considerations, we carry out a study in process automation using data-driven tools for a manufacturing process intended to produce high-quality containers. The first task involved studying the process, building and proving a hypothesis through data collection from experiments and the production line. Our hypothesis was the linear correlations between various sensor variables from our physical understanding of the process. We developed an automated process flow, i.e., a so-called Digital Twin (a numerical replication of the entire process) for this process to enhance the analytical and predictive capabilities of the process. This showed similar predictions when compared to static models. An automated in-line quality control algorithm was also built to remove the manual component from this task, using state-of-the-art computer vision techniques to utilize the power of data in the form of images. Lastly, to further provide the process engineers with predictive power for maintenance we carried out a few proof of concept projects to show the competence of such tools in minimizing costs and improving efficiency on the shop floor. All studies carried out showed great results and have immense potential to methodically use data to solve some of the pressing problems in the manufacturing sector

    Radiotracers for SPECT imaging: Current scenario and future prospects

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    Single photon emission computed tomography (SPECT) has been the cornerstone of nuclear medicine and today it is widely used to detect molecular changes in cardiovascular, neurological and oncological diseases. While SPECT has been available since the 1980s, advances in instrumentation hardware, software and the availability of new radiotracers that are creating a revival in SPECT imaging are reviewed in this paper. The biggest change in the last decade has been the fusion of CT with SPECT, which has improved attenuation correction and image quality. Advances in collimator design, replacement of sodium iodide crystals in the detectors with cadmium zinc telluride (CZT) detectors as well as advances in software and reconstruction algorithms have all helped to retain SPECT as a much needed and used technology. Today, a wide spectrum of radiotracers is available for use in cardiovascular, neurology and oncology applications. The development of several radiotracers for neurological disorders is briefly described in this review, including [ 123I]FP-CIT (DaTSCAN â„¢) available for Parkinson's disease. In cardiology, while technetium-99m labeled tetrofosmin and technetium-99m labeled sestamibi have been well known for myocardial perfusion imaging, we describe a recently completed multicenter clinical study on the use of [ 123I]mIBG (AdreView â„¢) for imaging in chronic heart failure patients. For oncology, while bone scanning has been prevalent, newer radiotracers that target cancer mechanisms are being developed. Technetium-99m labeled RGD peptides have been reported in the literature that can be used for imaging angiogenesis, while technetium-99m labeled duramycin has been used to image apoptosis. While PET/CT is considered to be the more advanced technology particularly for oncology applications, SPECT continues to be the modality of choice and the workhorse in many hospitals and nuclear medicine centers. The cost of SPECT instruments also makes them more attractive in developing countries where the cost of a scan is still prohibitive for many patients
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