Organ retention of gadolinium in mother and pup mice: Effect of pregnancy and type of gadolinium-based contrast agent

学位記番号：医博甲165

Study on the properties of proteinaceous waste from tannery

In Mongolia, solid waste from leather industry is considered as an environmental pollutant, and the issue of proper use and production of value-added products is lagging. In this study, we aimed to determine the physico-chemical characteristics of solid wastes from the leather industry, including cow hide, sheep and goat skin wastes. Based on our results, we determined utilization approach of such wastes. From the samples, lime splitting, trimming and shaving from the processing cow hide and pickles and tanned trimming from goat skin were relatively high in total protein and collagen content, ranging from 63-81%. Collagen, expressed as a percentage of total protein, was 53-97% in these wastes. Tannery wastes pose a risk of heavy metal pollution, andrelated chromium pollution is a focus of attention. According to the results of our research, the amount of chromium contained in solid waste was less than 3-4%, which shows that the domestic producers are following the technological regime to a certain extent. Untanned solid wastes such as the lime splitting and pickled hide/skin can be directly used in the production of protein products, and if other solid wastes are used as raw materials for protein-based products, it is necessary to solve the problem of additional technology for removing chromium. Арьс ширний үйлдвэрийн уурагт хаягдлын шинж чанарын судалгаа Хураангуй: Манай улсад арьс ширний үйлдвэрийн хатуу хаягдлыг байгаль орчныг бохирдуулагчийн хэмжээнд авч үзэж байгаа ба зүй зохистой ашиглаж, нэмүү өртөг шингэсэн бүтээгдэхүүн үйлдвэрлэх асуудал ихээхэн хоцрогдож байна. Бид энэхүү судалгаандаа арьс ширний үйлдвэрийн хатуу хаягдал болох үхрийн ширний (боловсруулаагүй арьсны захалгаа, махалгаа, шохойн хуулдас, захалгааны өөдөс, хусахын зоргодос, краст ширний захалгааны өөдөс), хонь (пикель), ямааны (пикель, захалгааны өөдөс) арьсны нийт есөн төрлийн хаягдлын физик-химийн үзүүлэлтийг харьцуулан тодорхойлж, ашиглах чиглэлийг тогтоохыг зорьсон. Шинжилгээнд хамруулсан дээжээс үхрийн ширийг боловсруулахад үүсэх шохойн хуулдас, захалгааны өөдөс, хусахын зоргодос, ямааны ширийг боловсруулахад үүсэх пикель, захалгааны зоргодос нь нийт уураг болон коллагены агууламжаар харьцангуй өндөр буюу 63-81%-ийн хооронд хэлбэлзэж байв. Нийт уурагт эзлэх коллагены хэмжээ нь эдгээр хаягдалд 53-97% байв. Арьс ширний үйлдвэрийн хаягдал нь хүнд металлын бохирдол үүсгэх эрсдэлтэй ба хромын бохирдлын асуудал анхаарлын төвд байдаг. Бидний хийсэн судалгааны дүнгээр хатуу хаягдалд агуулагдах хромын хэмжээ нь 3-4%-иас бага байсан нь үндэсний үйлдвэрлэгчид технологийн горимыг баримталж байгааг харуулж байна. Хром агуулаагүй хатуу хаягдал болох шохойн хуулдас, пикельдсэн арьсыг уурагт бүтээгдэхүүн үйлдвэрлэхэд шууд ашиглах боломжтой, бусад хатуу хаягдлуудыг уурагт суурилсан бүтээгдэхүүний түүхий эд болгон ашиглах тохиолдолд хромыг зайлуулах нэмэлт технологийн асуудлыг шийдэх хэрэгтэй байна. Түлхүүр үг: хромын идээлэггүй хаягдал, хромын идээлэгтэй хаягдал, коллаген уура

Applying Multi-Sensor Satellite Data to Identify Key Natural Factors in Annual Livestock Change and Winter Livestock Disaster (<i>Dzud</i>) in Mongolian Nomadic Pasturelands

In the present study, we tested the applicability of multi-sensor satellite data to account for key natural factors of annual livestock number changes in county-level soum districts of Mongolia. A schematic model of nomadic landscapes was developed and used to select potential drivers retrievable from multi-sensor satellite data. Three alternative methods (principal component analysis, PCA; stepwise multiple regression, SMR; and random forest machine learning model, RF) were used to determine the key drivers for livestock changes and Dzud outbreaks. The countrywide Dzud in 2010 was well-characterized by the PCA as cold with a snowy winter and low summer foraging biomass. The RF estimated the annual livestock change with high accuracy (R2 > 0.9 in most soums). The SMR was less accurate but provided better intuitive insights on the regionality of the key factors and its relationships with local climate and Dzud characteristics. Summer and winter variables appeared to be almost equally important in both models. The primary factors of livestock change and Dzud showed regional patterns: dryness in the south, temperature in the north, and foraging resource in the central and western regions. This study demonstrates a synergistic potential of models and satellite data to understand climate–vegetation–livestock interactions in Mongolian nomadic pastures

Effects of Gadolinium-Based Contrast Agents on Thyroid Hormone Receptor Action and Thyroid Hormone-Induced Cerebellar Purkinje Cell Morphogenesis

Gadolinium (Gd)-based contrast agents (GBCAs) are used in diagnostic imaging to enhance the quality of magnetic resonance imaging or angiography. After intravenous injection, GBCAs can accumulate in the brain. Thyroid hormones (THs) are critical to the development and functional maintenance of the central nervous system. TH actions in brain are mainly exerted through nuclear TH receptors (TRs). We examined the effects of GBCAs on TR-mediated transcription in CV-1 cells using transient transfection-based reporter assay and thyroid hormone-mediated cerebellar Purkinje cell morphogenesis in primary culture. We also measured the cellular accumulation and viability of Gd after representative GBCA treatments in cultured CV-1 cells. Both linear (Gd-diethylene triamine pentaacetic acid-bis methyl acid, Gd-DTPA-BMA) and macrocyclic (Gd-tetraazacyclododecane tetraacetic acid, Gd-DOTA) GBCAs were accumulated without inducing cell death in CV-1 cells. In contrast, Gd chloride (GdCl3) treatment induced approximately 100 times higher Gd accumulation and significantly reduced the number of cells. Low doses of Gd-DTPA-BMA (10−8–10−6 M) augmented TR-mediated transcription, but the transcription was suppressed at higher dose (10−5 – 10−4 M), with decreased β-galactosidase activity indicating cellular toxicity. TR-mediated transcription was not altered by Gd-DOTA or GdCl3, but the latter induced a significant reduction in β-galactosidase activity at high doses, indicating cellular toxicity. In cerebellar cultures, the dendrite arborization of Purkinje cells induced by 10-9 M T4 was augmented by low-dose Gd-DTPA-BMA (10−7 M) but was suppressed by higher dose (10−5 M). Such augmentation by low-dose Gd-DTPA-BMA was not observed with 10-9 M T3, probably because of the greater dendrite arborization by T3; however, the arborization by T3 was suppressed by a higher dose of Gd-DTPA-BMA (10-5 M) as seen in T4 treatment. The effect of Gd-DOTA on dendrite arborization was much weaker than that of the other compounds. These results indicate that exposure to specific GBCAs may, at least in part, cause toxic effects in the brain by disrupting the action of THs on TRs. The toxic effects of GBCAs may depend on the chemical structure of GBCA and the dose. Thus, it is very important to choose appropriate GBCAs for imaging to prevent adverse side effects

Fabrication of Wet-Spun Wool Keratin/Poly(vinyl alcohol) Hybrid Fibers: Effects of Keratin Concentration and Flow Rate

Sheep wool is one of the most common wastes derived from agriculture and also a great source of keratin. In this study, chemical reduction and alkali hydrolysis methods of extracting keratin from wool were studied for the purpose of reusing the waste wool, and the products were used to fabricate wet-spun hybrid fibers by mixing with PVA. The comparative yield of the two extraction methods was investigated, and the optimal precursor concentration ratio for keratin extraction was identified. The effects of keratin concentration and wet-spinning flow rate on the mechanical properties of fabricated fibers were studied. Therefore, this study encourages the further investigation of wool keratin-based hybrid biomaterials, which could provide a new way to reuse waste wool