Radiation Effects on Blends of Poly(ε-Caprolactone) and Diatomites

Poly(-caprolactone) (PCL) was blended with diatomaceous earth (diatomite) and irradiated with -rays to introduce cross-linking between PCL molecules or both components. The unwashed diatomite containing a little of a volatile component showed high efficiency of introduction of cross-linking, whereas that with no volatile component showed low efficiency of introduction of cross-linking. Elongational viscosity, melt viscosity, and modulus of PCL/diatomite blend irradiated at various doses were significantly improved. Enzymatic degradation of the PCL/diatomite blend became faster than that of the PCL, though that of the blend irradiated became slower.     

Recovery of gold by chicken egg shell membrane-conjugated chitosan beads

We have successfully prepared a bead-type adsorbent from two materials with different adsorption characteristics. Heavy metals were removed by greatly swollen egg shell membrane-conjugated chitosan beads. The egg shell membrane accumulated and removed precious metal ions from a dilute aqueous solution with a high affinity in a short contact time. Experiments suggested that chitosan beads could take up gold ions with great capacity and selectivity by conjugation with egg shell membrane. Under certain conditions, the selective removal of gold and copper in a mixture of gold and copper ions by egg shell membrane-conjugated chitosan beads was 100% and 2%, respectively. Egg shell membrane-conjugated chitosan beads can be seen as a promising material to recover gold in wastewater from various industries, such as electroplating.     

渚滑川河口拦门沙演变特性

河口拦门沙的存在可导致径流流出不畅，并能引起一系列的河口生态及环境问题。特别是弯曲型河口，在波浪流、河川径流及弯道副流的共同作用下，拦门沙的形成及演变将更为复杂。通过对日本渚滑川河口多次实地调查资料的分析，揭示了渚滑川河口拦门沙的演变特性。结果表明：渚滑川河口修筑防波堤后，在东北方向的海洋入射波作用下，拦门沙由河口右岸发育并向左岸逐渐延伸扩展，其河水流动也相应由右岸偏向左岸一侧；不论河口有无拦门沙，3次洪水在右岸的最大冲深均稳定在-6m高程，且河床横剖面的形状基本不变，即汛期时该河口河床形状已达平衡状态。     

Prenatal diagnosis of thalidomide syndrome

A case of thalidomide syndrome diagnosed by ultrasound in the 17th week of pregnancy is presented. The pregnant woman had leprosy and received adjuvant treatment with thalidomide. The affected fetus was exposed to the drug until the 35th day of pregnancy and presented absent external ears, upper limb phocomelia and absent tibiae and fibulae. No internal organ abnormalities were noticed at autopsy.     

Identification of the dimethylbenzyl mercapturic acid in urine of rats treated with 1,2,3-trimethylbenzene.

The structure was investigated of the mercapturic acid excreted in urine of rats after the i.p. administration of 1,2,3-trimethylbenzene. Of the two regioisomeric mercapturic acids, i.e. N-acetyl-S-(2,3-dimethylbenzyl)-L-cysteine and N-acetyl-S-(2,6-dimethyl-benzyl)-L-cysteine, only the former was isolated by preparative HPLC and identified, by comparison with an authentic specimen. The excretion rate of the mercapturate was estimated to be approximately 5% of dose, not a substantial metabolic route.     

Effects of lindane on Daphnia magna during chronic exposure

Abstract

Acute and chronic toxicity tests with lindane were conducted on Daphnia magna. The 24‐hr static LC50 was 1.64 mgL^‐1. The sublethal effects of 0.16, 0.25, 0.32, 0.60 and 0.80 mgL^‐1 lindane on the survival, reproduction and growth of D. magna were monitored for 21 days. The algae Nannochloris oculata (5 × 10⁵ cellsmL^‐1) was used to feed the daphnids. The parameters used to determined the effect of the pesticide on D. magna were:mean total young per female, mean brood size, days to first brood, intrinsic rate of natural increase (r), growth, and survival. Reproduction as well as survival was significantly reduced at lindane concentrations of 0.25 mgL^‐1 and higher. The intrinsic rate of natural increase (r) decreased with increasing concentrations of lindane. Growth, as measured by body length, was depressed significantly at 0.25 mgL^‐1 lindane and higher. The chronic data was used to formulate an acute/chronic ratio.     

Evaluation of a Daphnia magna renewal life‐cycle test method with diazinon

Abstract

Acute and chronic toxicity tests with diazinon (diethyl 2‐isopropyl‐6‐methyl‐4‐pyrimidinyl phosphorothionate) were conducted on Daphnia magna. The 24‐hr static LC50 was 0.86 μL.L^‐1. The sublethal effects of 0.05, 0.1, 0.5, 0.75 and 1.0 ngL^‐1 of diazinon concentrations on the survival, reproduction and growth of D. magna were monitored for 21 days. The algae Nannochloris oculata (5 x 10⁵ cellsmL^‐1) was used to feed the daphnids. The parameters used to determined the effect of the pesticide on D. magna were: mean total young per female; mean brood size; days to first brood; intrinsic rate of natural increase (r); growth; and survival. Reproduction as well as survival was significantly reduced at diazinon concentrations of 0.10 ngL^‐1 and higher. The intrinsic rate of natural increase (r) decreased with increasing concentrations of diazinon. Growth, as measured by body length, was depressed significantly at 0.05 ngL^‐1 of diazinon and higher concentrations. The maximum acceptable toxicant concentration (MATC) was calculated. The chronic data was used to formulate an acute/chronic ratio.     

Maternal genetic disorders and fetal development

With improvements in early diagnosis and management of genetic diseases, more women with genetic disorders are reaching reproductive age and becoming pregnant. While pregnancy can have a significant impact on a woman's health when there is an underlying genetic disorder, there can also be fetal effects, including embryopathy, fetal growth restriction, and brain injury. Some maternal genetic disorders are associated with adverse perinatal outcomes, including a high risk of perinatal loss and preterm birth. In this article, we review several maternal genetic disorders associated with fetal risk that are important for clinicians and patients to understand and manage appropriately. These include phenylalanine hydroxylase (PAH) deficiency and other inborn errors of metabolism, tuberous sclerosis complex, myotonic dystrophy, cystic fibrosis, Turner syndrome, sickle cell disease, and connective tissue disorders.