Analysis of Cement Deterioration in Outdoor High-Voltage Insulator.

Suspension type porcelain insulators used in overhead transmission lines comprise metal, ceramic, and cement. The deterioration of cement can lead to mechanical separation. For the degradation analysis, varied sizes of pores ranging from a few µm (capillary pores) to tens to hundreds of mm (detectable by naked eyes) were considered. Cracks that were hard to view with naked eyes were identified by staining with a fuchsine solution. The hydrogen ion concentration and pH value indicate the extent to which the cement is deteriorated. The longer the cement is used, the lower its pH value. High mechanical strength is considered an important advantage of porcelain insulators, and it may decline, if the cement is used for a longer period of time. Water ingress may also occur, resulting in expansion, due to the rehydration of the cement. The process and mechanism of expansion of cement, due to infiltration of water were described. As a method of analysis, a universal indicator was employed to evaluate the pH changes in cement. It was observed that the pH value was 12-13 for new products. However, for products that were used for 52 years, the pH value was under 7, which indicated an acidic tendency, due to deterioration.

Distribution of cortical bone in bovine limbs.

Xenogenic bone grafts have been widely researched because they are not limited in terms of volume and size like autogenous and allogenic grafts, and the favored bone for xenografts is bovine bone. However, the efficacy of cortical bone from bovine limb for xenografts is not clearly known. In this study, the distribution of cortical bone in bovine humerus, radius, femur, and tibia were investigated. Each experimental bone was split longitudinally with a bone saw and bone marrow and cancellous bone were removed. The thicknesses of cortical layers in sample diaphyses were measured at 1cm intervals using a micrometer. The mean lengths of cortical portions were; humerus 14.7 +/- 2.3 cm, radius 19.0 +/- 2.6 cm, femur 19.0 +/- 3.2 cm, and tibia 23.0 +/- 3.1 cm. Thickest cortical bone was found at the distal caudal metaphysis of the humerus, the proximal caudal metaphysis of the radius, the craniolateral and caudomedial midshaft of the femur and the lateral and medial midshaft of tibia. The mean surface areas of cortical bone were humerus 187.4 +/- 15.44 cm2, radius 229.2 +/- 43.31 cm2, femur 295.8 +/- 8.93 cm2, and tibia 290.0 +/- 30.44 cm2. And, mean volumes of cortical bone were humerus 149.42 +/- 15.35 cm3, radius 166.26 +/- 20.02 cm3, in femur 220.45 +/- 22.73 cm3, and tibia 214.89 +/- 20.05 cm3. The results of this study can be used to produce cortical bone-based plates and screws.

Effects of Safflower seed oil in osteoporosis induced-ovariectomized rats.

The effects of Korean Safflower (Carthamus tinctorius L) seed oil (SSO) on osteoporosis induced-ovariectomized rats were investigated. A total of 90 female Sprague-Dawley rats, 4-month-old, weighing 200-230 g were randomly assigned into 3 groups (30 animals/group). The animals in group I were sham operated and those of group II and III were ovariectomized (Ovx). After eight weeks, the animals of group I and II received solvent vehicle daily, whereas those of group III were administered SSO orally (1 ml/kg) daily for 30 days. The changes in the serum levels of insulin-like growth factor-I (IGF-I), IGF-II, insulin-like growth factor binding protein-3 (IGBP-3), estrogen, total alkaline phosphatase (TALP), bone-specific alkaline phosphatase (BALP), calcium and phosphorous in serum, and also the histomorphology of the proximal tibia metaphysis and femur/body weight (F/B) ratio were examined in all the groups at every 10 days interval. Thirty days later, IGF-I, IGF-II, IGBP-3 and BALP levels were significantly increased (p < 0.05) in group III as compared to groups I and II. There were no significant differences in serum levels of estrogen, TALP and F/B ratio between groups II and III, but estrogen levels were higher in group I. These results suggest that the safflower seeds have possible roles in the improvement of osteoporosis induced-ovariectomized rats.

Trochleoplasty in lateral patellar luxation in two calves.

Two Holstein Friesian calves were referred to the Animal Medical Center of Chonbuk National University with severe lameness on the hind limb(s), flexed stifle joint and an inability to walk since birth. Based on the clinical history, clinical findings and radiography of the stifle joint, the cases were diagnosed as grade III lateral patellar luxation (LPL). Trochleoplasty along with medial retinacular reinforcement and lateral release were performed in both calves. The calves recovered 3 to 4 weeks after surgery. Trochleoplasty along with medial retinacular reinforcement and lateral release can be an effective technique for the treatment of LPL in calves.

Total hip replacement in a dog.

An intact male German shepherd dog (4 y, body wt. 35.5 kg) was referred to the Animal Medical Center, Chonbuk National University with severe lameness, pain and gait abnormality on the right hind limb. Survey radiographs of the pelvis revealed dysplasia of the right coxofemoral joint with subluxation. The dog was surgically treated performing total hip replacement (THR) using Modular Biolox Canine Modular THR System. The dog began to bear weight and slowly returned to a normal exercise pattern 2 months after surgery. THR resulted in satisfactory clinical functions with 6 months follow up and no complications were observed. Canine modular THR could be a successful modality for the management of disabling conditions of the coxofemoral joint.