The present study is focused on studying the swelling kinetics, thermal and aqueous stabilities, and determination of various forms of water in the chitosan (CS) and polyacrylonitrile (PAN) blend and semi-interpenetrating polymer network (sIPN). CS/PAN blend hydrogel films were prepared by solution casting technique. The blend film with optimum swelling properties was selected for the synthesis of sIPN. CS in the blend was crosslinked with the vapors of Glutaraldehyde (GTA) to prepare sIPN. The fabricated CS/PAN blend and sIPN hydrogels films were characterized with Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA) and field emission scanning electron microscope (FESEM). The kinetics of swelling, bound and unbound waters and aqueous stability were determined experimentally. FESEM showed good miscibility between CS and PAN, FTIR showed no chemical interaction between CS and PAN; however, it did show a doublet for the sIPN, TGA showed improved thermal stability and swelling kinetic followed second order kinetics. The degree of swelling of the sIPN hydrogels samples at room temperature varied from ~2200 % (with a fair degree of stability (~30 %)) to ~1000 % (with high degree of aqueous stability (43 %)) with increase in the crosslinking time. The calculated unbound water (WUB) max., for the blend was 52.3 % whereas for the bound (WB) the max., was 41.9 %. However, for sIPN hydrogel films, the WUB water decreased (max. 21.0 %) where as the WB increased (max. 52.0 %). The decrease in WUB and increase in the WB is attributed to the formation of a compact structure and increase in the contact area between the water and polymers in sIPN hydrogels due to the induction of new water contacting point in these hydrogel films, respectively. 相似文献
The present study was carried out to identify the excretory/secretory (E/S) antigens of the rumen infecting digenetic trematode Gastrothylax crumenifer that may be useful for the immunodiagnosis of rumen amphistomosis particularly during the pre-monsoon season during which this rumen parasite stops shedding eggs. The in vitro released E/S proteins were purified on a Sephadex G-200 column. The gel filtration profile revealed three distinct fractions F1-F3 where F1 and F3 appeared as sharp peaks while the F2 fraction was dispersed. The antibody titre against each of the purified E/S fractions was determined by ELISA using anti-whole E/S polyclonal antibodies raised in rabbit. Among the three fractions, the antibody titre against F1 was highest (1:12,800) whereas IgG titre was very low (1:50) for fraction F2 and F3 (1:100). Of the total polypeptides resolved on gradient SDS-PAGE, only a few antigenic polypeptides were detected in each fraction with hyperimmune anti-serum as revealed by Western Blot analysis. However, a 33 kDa antigen detected in each fraction appeared to be immunodominant which could be exploited for the diagnosis of the pouched amphistome. 相似文献
The progressive morphohistopathologic changes, distribution pattern of lesions and ultrastructural characteristics in Eimeria arloingi infection were investigated in experimentally infected kids. The 18 newborn animals allocated to 3 equal groups. Two of groups,
A, B were inoculated with a single dose of 1 × 103 and1 × 105 sporulated oocysts of E. arloingi, respectively. At 7, 14, 21, 28, 35, and 42 days postinoculation (DPI), 1 kid from each group was necropsied for pathologic
and ultrastructural studies. Progressive lesions were present at 21, 28, 35 and 42 DPI in the jejunum, ileum, cecum with fewer
in the duodenum and proximal colon. The oocysts shedding begin between 16 to 18 DPI. Grossly, minimal changes were observed
at 21 DPI as few whitish plaques or nodules and advanced lesions at 42 DPI as pseudoadenomatous pattern in the mucosa and
a cerebriform pattern on the serosal surface of jejunum and ileum. Early histopathologic lesions due to schizogony phase were
including presence of intracytoplasmic developmental stages of the parasite such as trophozoites, immature to mature schizonts
and mild infiltration of inflammatory cells. In late lesions due to various stages of gametogony, the histological pattern
was mainly remarkable hyperplasia of the villi and crypts epithelial cells, eventually developed into papillary projections
of reactive epithelium. The mesenteric lymph nodes showed a few numbers of large schizonts in the cortical lacteals. This
study showed E. arloingi as a highly pathogenic species for kids, the incubation period was 16–18 days and the main target organ was jejunum with
characteristic morphohistopathologic lesions. 相似文献
The use of morphine has been demonstrated to increase susceptibility to infections. Herpes simplex virus type 1 (HSV-1) is a highly successful pathogen among immunocompromised individuals. In the present study, due to the importance of HSV vaccination in morphine abusers, the effects of chronic morphine exposure on the host response to a HSV-1 gB DNA-based vaccine have been investigated. The study is addressing an important aspect of vaccine development among the susceptible (immunocompromised) hosts. BALB/c mice were exposed to morphine over 11 days. They were then vaccinated with DNA vaccine or KOS strain as a live vaccine. The findings showed that the morphine-treated animals failed to respond to DNA vaccination evaluated by the anti-HSV gB antibody titer, delayed type hypersensitivity (DTH) and lethal HSV-1 challenge. Under the same conditions, the KOS vaccine showed a reduced Ab titer and DTH response in morphine-treated mice, but could protect mice against the lethal challenge and was safe for vaccination of morphine-treated animals. 相似文献
Eggs from a broiler line were incubated at two different altitudes and hatched. Relative heart and lung weights, volumes of the heart, lung and thoracic cavity, incidence of right ventricular hypertrophy and ascites, and related physiological parameters were followed in the day-old chickens hatched from the above eggs. Lung and heart weights as a percentage of body weight, lung and heart volumes relative to the volume of the thoracic cavity after removing the heart and lungs were higher in chickens hatched at high altitude. Additionally, embryonic triiodothyronine (T3) and thyroxine (T4) levels relative to cardiopulmonary parameters were higher in day-old chickens that hatched at high altitude as compared with chickens hatched at low altitude. This was associated with a lower incidence of right ventricular hypertrophy and ascites in chickens hatched at high altitude. Our data indicate that chronic hypoxia interacting with the endogenous functions of embryos during embryonic development at high altitude, as adaptation mechanisms, changed the developmental trajectories of cardiopulmonary parameters in postnatal chickens. This important development facilitates an increase in the gas exchange area in broiler chickens, thus lowering their susceptibility to pulmonary hypertension and ascites. 相似文献
Aquaculture is a major supplier of animal protein for Bangladesh’s population, and the Mymensingh division is a major contributor to finfish aquaculture, producing 43% of the total pond pangasius and 9% of the total amount of tilapia (figures from 2018). We conducted a finfish farmer survey covering Netrokona, Jamalpur and Mymensingh districts to understand current finfish farming practices and identify factors that drive farmers in their species choice between pangasius or tilapia cultivation. We found that most finfish farmers in Mymensingh are experienced practitioners and practise polyculture with a range of stocking densities for each species. Using an economic model of polyculture practice, we have shown that over a production cycle, pangasius gain body mass at a rate nearly 4 times greater than that for tilapia, resulting in substantially larger revenues and providing a strong incentive for their culture. High levels of tilapia aquaculture likely persist due to their short production cycle and an associated decreased economic risk due to crop loss from disease, both factors providing a strong incentive for their culture. Our findings also indicate production yield differences through different species selection in polyculture systems. For example, co-culturing pangasius, tilapia and carp together was less productive than co-culture of pangasius with tilapia. Furthermore, higher yields of tilapia were obtained when co-cultured with carp compared with pangasius, the reasons for which are not known and warrant further investigation. Our study uses information provided by finfish farmers to produce a useful guide on fish species choices to maximise production yields, and therefore food production, from their ponds.
The karyotype and chromosomal characteristics of endangered Caspian salmon, Salmo trutta caspius, in the southern part of the Caspian Sea were investigated. From the total of 60 mitotic metaphases achieved from 15 individuals, 15, 9 and 36 metaphases were with the mode <76, 76 and 80 representing 25%, 15% and 60% of metaphases respectively. So, the most common pattern of chromosome number was 80 (36 metaphases, 60%) and the number of diploid chromosomes was thus confirmed as (2n=80) of this subspecies. The karyotype consists of seven metacentric, five submetacentric and 28 telocentric pairs. The karyological parameters of the Caspian salmon, the centromic index, arm ratio, relative length and length variation range of chromosomes, were 0–0.5, 1–∞, 0.011–0.045 and 0.507–2.028 μm respectively. The total length of chromosomes in haploid series was 44.776 μm and fundamental number of chromosome arms was 104. This study may provide the first knowledge on chromosome analysis in Caspian salmon and add basic information useful for its chromosomal manipulations. 相似文献
The accumulation of inbreeding and the loss of genetic diversity is a potential problem in Holstein dairy cattle. The goal of this study was to estimate inbreeding levels and other measures of genetic diversity, using pedigree information from Iranian Holstein cattle. Edited pedigree included 1 048 572 animals. The average number of discrete generation equivalents and pedigree completeness index reached 13.4 and 90%, respectively. The rate of inbreeding was 0.3% per year. Effective number of founders, founder genomes, non‐founders and ancestors of animals born between 2003 and 2011 were 503, 15.6, 16.1 and 25.7, respectively. It was proven that the unequal founder contributions as well as bottlenecks and genetic drift were important reasons for the loss of genetic diversity in the population. The top 10 ancestors with the highest marginal genetic contributions to animals born between 2003 and 2011 and with the highest contributions to inbreeding were 48.20% and 63.94%, respectively. Analyses revealed that the most important cause of genetic diversity loss was genetic drift accumulated over non‐founder generations, which occurred due to small effective population size. Therefore, it seems that managing selection and mating decisions are controlling future co‐ancestry and inbreeding, which would lead to better handling of the effective population size. 相似文献