64 research outputs found
Preoperative 99mTc-sestamibi scintigraphy in patients with primary hyperparathyroidism and concomitant nodular goiter: Comparison of SPECT-CT, SPECT, and planar imaging
Background: Investigations using a hybrid single photon emission computed tomography/computed tomography (SPECT-CT) scanning technique have been carried out in limited studies and have shown mixed results. However, the assessment of this technique for the detection of parathyroid adenoma in patients with a nodular goiter was performed in only one study with a small sample size. The aim of this prospective study was to assess the role of Tc-sestamibi parathyroid SPECT-CT scans for localization of parathyroid adenomas with a concomitant nodular goiter using Tc-methoxyisobutyl isonitrile (MIBI) scintigraphy and to compare it with SPECT and planar imaging. Methods: This study was conducted on 48 patients with primary hyperparathyroidism and nodular goiter, who were candidates for parathyroid surgery and had been referred for parathyroid scintigraphy. The patients underwent an early set of planar Tc-MIBI scanning procedures first, followed by SPECT and CT scannings, and finally a delayed set of planar Tc-MIBI scannings. Sensitivity, specificity, negative and positive predictive values, and accuracy were determined on a per-parathyroid-gland basis for each scanning method, as defined by histology and follow-up. Results: The surgery was successful in 48 out of 50 patients with primary hyperparathyroidism concomitant with thyroid nodularity, and data were completed for 80 sites in 48 patients. The accuracy of SPECT-CT in correctly identifying a parathyroid adenoma was 85.00, versus 75.00% for SPECT (P=0.01, significant). The sensitivity and specificity for SPECT-CT were 77.55 and 96.77%, respectively, versus 67.34 and 87.09%, respectively, for SPECT (P=0.12 and 0.12, not significant). There were nine sites that showed better localization on SPECT-CT scans relative to SPECT images, of which five sites were located in the ectopic regions. Conclusion: The results of our study indicate that SPECT-CT is more accurate than sestamibi planar imaging and SPECT for the preoperative identification of parathyroid lesions in patients with primary hyperparathyroidism concomitant with thyroid nodularity. Also, we would recommend the use of SPECT-CT for a workup of all patients with ectopic glands who are scheduled for minimally invasive parathyroid surgery. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins
1,4-Bis[2-(prop-1-enyl)phenoxy]butane
The molecule of the title compound, C22H26O2, exhibits Ci molecular symmetry with a crystallographic inversion centre at the mid-point of the central C—C bond. A kink in the molecule is defined by the torsion angle of 66.7 (2)° about this central bond of the alkyl bridge
Reproductive maturation of sub adult Indian carps in earthen ponds
Carp culture in extensive and semi-extensive systems: i.e., earthen ponds, natural and semi-natural water resources, reservoirs and the paddy field has widspred distribution. Indian major carps including Catla (Catla catla), Roho (Labeo rohita), Mrigal (Cirrhinus mirgala) which have faster growth and good feed value than other warm water fishes introduced to many countries including India, Thailand, Burma, Philippines, Japan and the former Soviet Union are also considered and are reared. Sex steroids are important in the control of reproduction in fish. Development of methods for Indian education programs for proliferation requires knowledge of the hormonal changes during sexual maturation and spawning is. Testosterone, progesterone and 17 ϐ-estradiol are steroid hormones that play an important role in controlling Tuesday reproduction and sexual maturity of the fish are. This study aimed to investigate the changes in steroid hormones testosterone and 17 beta-estradiol including Catla (Catla catla), Roho (Labeo rohita), Mrigal (Cirrhinus mirgala) were conducted in different seasons. 40 specimen of carps breeders were investigated in southern (Aquaculture Research Institute) and north (North Aquaculture Research Institute) of Iran and maintained in different seasons (spring, summer, autumn, winter). Fish were caught by netting vetch and spring 1 cm. Blood samples were collected from the fish caudal blood serum by centrifugal separation model Labofuga 200 was made in Germany. Testosterone, and estradiol RIA (Radioimmunoassy) using an automatic gamma counter LKB model made in Finland made in France using the Immunotech kit hormone were measured. The results showed that the average level of 17 betaestradiol in the female in the spring, summer, autumn and winter, respectively, 82/12 ± 75/107, 66/13 ± 2/80, 73/17 ± 8/122 and 72/17 ± 25/104 ml, respectively. Mean testosterone levels in the female in the spring, summer, autumn and winter, respectively, 004/0 ± 092/0, 002/0 ± 05/0, 003/0 ± 11/0 and 006/0 ± 1/0 ng ml, respectively. Overall, the highest levels of 17 beta-estradiol and testosterone in female Roho were recorded in autumn. Also, low levels of 17 beta-estradiol and testosterone in female Roho was observed in summer. Highest and lowest levels of the male hormone, respectively, were recorded in winter and spring. The relationship between the hormone 17 beta-estradiol and testosterone with environmental factors such as pH and dissolved oxygen were discussed. there was a positive correlation between testosterone levels in males only the amount of dissolved oxygen .results revieled that sex hormone levels were increased during winter and autumn would be the signe for reproductive performance and spawning seasone in three species
Vibration analysis of viscoelastic single-walled carbon nanotubes resting on a viscoelastic foundation
Vibration responses were investigated for a viscoelastic Single-walled carbon nanotube (visco-SWCNT) resting on a viscoelastic foundation. Based on the nonlocal Euler-Bernoulli beam model, velocity-dependent external damping and Kelvin viscoelastic foundation model, the governing equations were derived. The Transfer function method (TFM) was then used to compute the natural frequencies for general boundary conditions and foundations. In particular, the exact analytical expressions of both complex natural frequencies and critical viscoelastic parameters were obtained for the Kelvin-Voigt visco-SWCNTs with full foundations and certain boundary conditions, and several physically intuitive special cases were discussed. Substantial nonlocal effects, the influence of geometric and physical parameters of the SWCNT and the viscoelastic foundation were observed for the natural frequencies of the supported SWCNTs. The study demonstrates the efficiency and robustness of the developed model for the vibration of the visco-SWCNT-viscoelastic foundation coupling system
Manufacture Techniques of Chitosan-Based Microcapsules to Enhance Functional Properties of Textiles
In recent years, the textile industry has been moving to novel concepts of products, which could deliver to the user, improved performances. Such smart textiles have been proven to have the potential to integrate within a commodity garment advanced feature and functional properties of different kinds. Among those functionalities, considerable interest has been played in functionalizing commodity garments in order to make them positively interact with the human body and therefore being beneficial to the user health. This kind of functionalization generally exploits biopolymers, a class of materials that possess peculiar properties such as biocompatibility and biodegradability that make them suitable for bio-functional textile production. In the context of biopolymer chitosan has been proved to be an excellent potential candidate for this kind of application given its abundant availability and its chemical properties that it positively interacts with biological tissue. Notwithstanding the high potential of chitosan-based technologies in the textile sectors, several issues limit the large-scale production of such innovative garments. In facts the morphologies of chitosan structures should be optimized in order to make them better exploit the biological activity; moreover a suitable process for the application of chitosan structures to the textile must be designed. The application process should indeed not only allow an effective and durable fixation of chitosan to textile but also comply with environmental rules concerning pollution emission and utilization of harmful substances. This chapter reviews the use of microencapsulation technique as an approach to effectively apply chitosan to the textile material while overcoming the significant limitations of finishing processes. The assembly of chitosan macromolecules into microcapsules was proved to boost the biological properties of the polymer thanks to a considerable increase in the surface area available for interactions with the living tissues. Moreover, the incorporation of different active substances into chitosan shells allows the design of multifunctional materials that effectively combine core and shell properties. Based on the kind of substances to be incorporated, several encapsulation processes have been developed. The literature evidences how the proper choices concerning encapsulation technology, chemical formulations, and process parameter allow tuning the properties and the performances of the obtained microcapsules. Furthermore, the microcapsules based finishing process have been reviewed evidencing how the microcapsules morphology can positively interact with textile substrate allowing an improvement in the durability of the treatment. The application of the chitosan shelled microcapsules was proved to be capable of imparting different functionalities to textile substrates opening possibilities for a new generation of garments with improved performances and with the potential of protecting the user from multiple harms. Lastly, a continuous interest was observed in improving the process and formulation design in order to avoid the usage of toxic substances, therefore, complying with an environmentally friendly approach
Fractional‐order sliding mode control for damping of subsynchronous control interaction in DFIG‐based wind farms
- …