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Issue Info: 
  • Year: 

    1395
  • Volume: 

    1
Measures: 
  • Views: 

    552
  • Downloads: 

    0
Abstract: 

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Yearly Impact:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Author(s): 

Issue Info: 
  • Year: 

    2022
  • Volume: 

    77
  • Issue: 

    -
  • Pages: 

    0-0
Measures: 
  • Citations: 

    1
  • Views: 

    1
  • Downloads: 

    0
Keywords: 
Abstract: 

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Author(s): 

JAHANSHAHI M.

Issue Info: 
  • Year: 

    2004
  • Volume: 

    2
  • Issue: 

    1
  • Pages: 

    1-12
Measures: 
  • Citations: 

    0
  • Views: 

    414
  • Downloads: 

    320
Abstract: 

There has been much interest generated in the recovery of nanoparticulate (nanoparticle) bioproducts (Second generation of biotechnological products) such as plasmid DNA and viruses as putative gene therapy vectors, macromolecular assemblies as drug delivery vehicles and virus-like particles as vaccine components. Such product must be manufactured in advanced stages of purity, material definition and sophisticated formulation to rival those demanded of the pharmaceutical macromolecules which dominate as the first generation products. Nanoparticulates are characterized by a critical size range (10-300 nm diameter) and complexity of surface chemistry and internal organisation which pose new challenges in separation science and engineering, controlled chemistries of modification and material measurement not readily addressed by extant technologies. Current review article is concerns with structural characterisations of nanoparticulate bioproducts as well as redesign of their downstream processing techniques which are common to all programmes. This focus is upon candidate partition systems which can contribute to the fractionation, recovery and purification of nanoparticulate assemblies from their soluble components (capsid proteins from virus, polynucleotides from plasmid DNA, soluble, agglomerated forms of protein etc.). The mechanistic design of new separation and formulation technologies based upon a sound understanding of quantifiable structural features of these nanoparticle bioproducts is strongly indicated.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2018
  • Volume: 

    14
  • Issue: 

    3
  • Pages: 

    67-78
Measures: 
  • Citations: 

    0
  • Views: 

    222
  • Downloads: 

    76
Abstract: 

Production of human proteins in Pichia pastoris has significant advantages. However, there is still need for improvement of various stages of its downstream processing like clarification and purification. In fact downstream processes are usually the most critical part of production of biotech products. This work aimed to evaluate the effect of two steps added to the downstream processes of human growth hormone (hGH) production in Pichia pastoris. Firstly, the effect of clarification, with activated carbon, on capture of hGH by ion exchange chromatography (IEC) was investigated. For this purpose, a clarification process using activated carbon was used to remove process contaminants like pigments. The clarified sample was applied to the IEC column and the recovery of hGH, following IEC, was assessed using SDS-PAGE, Bradford protein assay, and area under the curve (AUC). The obtained results showed that the AUC values were 2. 81 and 5. 61 for the with-and without-treatment samples, respectively. Protein recovery of clarified sample with activated carbon was 541 mg in comparison with 328 mg for the sample without treatment. The yield of IEC was also improved from 50. 46% to 83. 23% following treatment with activated carbon. Secondly, the effect of three concentrations of ammonium sulfate in the binding buffer on resolution of hGH upon elution on hydrophobic interaction chromatography (HIC) was investigated. Biological activity was used as the main criterion for evaluation of purified hGH using HIC. The obtained results indicated that by increasing the concentration of ammonium sulfate form 1 to 3 mol/L, resolution of hGH was improved, as the purified fraction using 3 mol/L of ammonium sulfate showed a specific activity of 3. 1IU/mg. So, the results of the present study demonstrated that activated carbon is a promising candidate for efficient clarification of recombinant hGH and for improving the efficiency of the capture step. Therefore, it can be considered by biotech companies as a cost-effective and sustainable clarification procedure of recombinant proteins from high cell density cultures. This study also revealed that 3% ammonium sulfate has a positive effect on the separation of hGH variants with the desired biological activity.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2024
  • Volume: 

    79
  • Issue: 

    1
  • Pages: 

    102-110
Measures: 
  • Citations: 

    0
  • Views: 

    12
  • Downloads: 

    1
Abstract: 

Newcastle disease virus from the Paramyxoviridae family is a single-stranded negative-sense RNA virus. NDV is an infection of domestic poultry and nearly all bird species. It has been a very severe difficulty for the poultry industry all over the world Even though it remains a potential threat to poultry industries, this virus is a powerful oncolytic virus as well. In this study a process was accomplished to achieve concentrated and highly purified NDV V4 strain particles. Downstream processing of Newcastle virus strain V4 was characterized by amplifying virus in embryonated chicken eggs. Through a sequence of steps, harvesting allantoic fluid, clarification by centrifuge, concentration by ultrafiltration, size exclusion separation, the reduced volume and pure virus particles were considered for the amount of ovalbumin, hemagglutinin activity, electron microscopy (TEM), electrophoresis, and additionally immunogenicity of prepared antigens. The results presented a high recovery of HA activity in concentrated and pure virus with removing of ovalbumin and the typical morphology based on TEM. Sepharose CL-4B was determined as the best media among all used resins to purify the virus. Prepared formulations as vaccines demonstrated a positive hemagglutinin inhibition for 6 months duration and stable for two years. Organized study provided strong evidence that this method was quite appropriate in concentrating and purifying of intact Newcastle disease virus to use in vaccine research, also in antiserum preparation, or probably like an oncotic agent as an alternative to conventional procedures. Though additional studies are being tested, this procedure can be used practically on a semi-industrial scale in the production of multiple vaccine components.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2024
  • Volume: 

    13
  • Issue: 

    25
  • Pages: 

    126-144
Measures: 
  • Citations: 

    0
  • Views: 

    18
  • Downloads: 

    0
Abstract: 

In this paper, an alternative approach in operational modal analysis is presented, utilizing image processing technique and transmissibility functions. Imaging sensors do not impose additional mass on the structure due to their non-contact nature, while transmissibility functions, independent of excitation type, can directly extract mode shapes. The innovation of this research lies in combining these two techniques to record dynamic responses and identify modal properties. To capture the temporal response history from video signals, the block-matching method with sub-pixel accuracy was employed. Validation was conducted by recording the response of the tip of a cantilevered steel beam subjected to impact excitation, using a high-speed camera and a laser vibrometer, simultaneously. The RMSE plots in the time domain and the PSD in the frequency domain indicate high accuracy of this method. Using this approach, the displacement time histories of various points on the structure were extracted from the video signals, and the modal properties, including natural frequencies, damping ratios, and mode shapes, were identified using the transmissibility matrix method. The results obtained from the proposed method were compared with the stochastic subspace identification (SSI) method and analytical solutions. The findings reveal the accuracy of the modal identification approach introduced in this article. The highest relative error in estimating the natural frequencies of the first and second modes, compared to the values from the laser method, are 0.19% and 0.13%, respectively, and in comparison to the analytical values, they are 0.34% and 1.5%, respectively.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2005
  • Volume: 

    4
Measures: 
  • Views: 

    224
  • Downloads: 

    209
Abstract: 

During the production of recombinant human insulin, before final refolding, the S-S bonds need to be opened in a process of oxidative breakdown called sulfitolysis. In this process, sulfur atoms are converted into-SO3-. Sulfitolysis is a crucial step in the whole downstream process as it can produce the higher amount of properly folded fusion protein feeding the later digestion process; therefore make it vulnerable to higher scrutiny and optimizations. Circular dichroism is a top of the line instrumentation technology to elucidate the secondary structure of the proteins and peptides. Using this technique would help to not only compare the structural manipulations in a step-wise process, but also to quantify the elements of the secondary structure in each step. This method proved to be an effective downstream method optimizing assistant while having the capability of being routinely used as a complementary QC instrument, which can identify the nature of peptide folding in each step.

Yearly Impact:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 224

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Issue Info: 
  • Year: 

    2024
  • Volume: 

    13
  • Issue: 

    25
  • Pages: 

    93-125
Measures: 
  • Citations: 

    0
  • Views: 

    19
  • Downloads: 

    0
Abstract: 

In traditional speech processing, feature extraction and classification were conducted as separate steps. The advent of deep neural networks has enabled methods that simultaneously model the relationship between acoustic and phonetic characteristics of speech while classifying it directly from the raw waveform. The first convolutional layer in these networks acts as a filter bank. To enhance interpretability and reduce the number of parameters, researchers have explored the use of parametric filters, with the SincNet architecture being a notable advancement. In SincNet's initial convolutional layer, rectangular bandpass filters are learned instead of fully trainable filters. This approach allows for modeling with fewer parameters, thereby improving the network's convergence speed and accuracy. Analyzing the learned filter bank also provides valuable insights into the model's performance. The reduction in parameters, along with increased accuracy and interpretability, has led to the adoption of various parametric filters and deep architectures across diverse speech processing applications. This paper introduces different types of parametric filters and discusses their integration into various deep architectures. Additionally, it examines the specific applications in speech processing where these filters have proven effective.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2006
  • Volume: 

    8
  • Issue: 

    2 (30)
  • Pages: 

    14-18
Measures: 
  • Citations: 

    0
  • Views: 

    1316
  • Downloads: 

    0
Abstract: 

BACKGROUND AND OBJECTIVE: Varicocele is one of the causes of male infertility. It changes with temperature and drainage of testicular veins that due to spermatogenesis disturbance and decrease of fertility in these patients. However varicocelectomy is a treatment for varicocele, but there are other methods of treating this disease including assisted reproductive technology (ART), Sperm processing and swim up. METHODS: This interventional study was performed on 155 cases in fertility and infertility Center of Babol University of medical sciences in 2004. Sperm parameters in varicocele patients was assessed before and after sperm processing. FINDINGS: The mean age of patients was 31.8 years. Sperm motility before sperm processing in grade III and IV was 53.9% and 12.9%, respectively but after sperm processing in grade III and IV changed to 78.7% and 56.8%, respectively. Total motility before sperm processing was 40 % and changed after processing to 80%. CONCLUSION: The results show that with sperm processing and collection of appropriate sperms, we are able to increase fertility.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    1388
  • Volume: 

    2
Measures: 
  • Views: 

    667
  • Downloads: 

    0
Abstract: 

تهیه و نگهداری نقشه جغرافیایی جامع الکترونیکی برای یک شهر یکی از مهمترین ویژگیهای شهرهای الکترونیکی محسوب می شود. این نقشه می ‏بایستی توانایی ارایه خدمات چند لایه ‏ای و مشخص نمودن موقعیت دقیق جغرافیایی آن محل از زمین را داشته باشد. از سویی دیگر، سرویس های مبتنی بر GPS های معمولی خطاهای نامطلوبی را ارایه می‏ کنند. لذا می بایستی از سیستم های نوین دیگری استفاده نمود تا به نیازهای خدمات شهری بطور مناسب پاسخ داده ‏شوند. در این مقاله سعی بر آن شده است تا متداول‏ترین روشهای نوین که همان DGPS می ‏باشد را معرفی نماییم. و همین طور در کشورهایی که به سیستم کاداستر مجهز می باشند، شبکه GNSS که بر همین اساس طراحی و پیاده سازی شده است، مورد بررسی قرار گیرد. در پایان کاربردهای مفید این نوع سیستم ‏ها بر روی خدمات شهری مطرح می ‏گیرند.

Yearly Impact:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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