废水活性污泥处理过程去除TMV效果研究

对间歇及连续运行废水活性污泥处理过程去除人为污染高浓度烟草花叶病毒(tobaccomosaicvirus,TMV)的效率及其影响因素进行了研究.结果显示活性污泥去除TMV的效果受工艺参数的影响,其中污泥浓度直接影响所加入TMV的去除效率.同时,曝气强度也影响病毒的去除效率.在2个具不同运行工艺参数的活性污泥系统中连续加入枯斑数达(2 5～6 7)×104·L-1的TMV,连续运行一周其去除率仍均大于98%.当污泥BOD负荷率在0 534～0 899kg·(kg·d)-1,水力停留时间在4 8～10 2h,平均MLVSS在1780～3250mg·L-1范围内,TMV的去除效率同这些参数关系不大,说明活性污泥系统可有效地去除植物病毒而不过分地依赖于工艺条件,这为活性污泥法去除植物病毒的稳定性提供了保证.然而病毒的去除不等于灭活,很大程度上病毒仅是从液相转移到了固相,污泥中的病毒浓度往往比游离高出许多倍.因此在污泥农用、处置时要充分考虑到污泥的病毒学安全性问题.同时,在评价废水处理的有效性时也要考虑到这种现象.     

Estimates of yield loss and virus titre in sorghum hybrids infected with maize dwarf mosaic virus strain B

Sorghum genotypes having the red-leaf reaction to infection by maize dwarf mosaic virus strain B had significantly higher virus concentrations and 33–755 yield reductions. Sorghum having only the mosaic reaction to infection had low virus levels and 0–8% yield reductions.     

Effects of pyrethroids (Cypermethrin and deltamethrin) on the disease expression of cowpea aphid-borne mosaic virus

The effect of the pyrethroids, cypermethrin and deltamethrin, on the behaviour of Alphis craccivora and on the transmission of cowpea aphid-borne mosaic virus (CAMV) was compared to that of dimethoate (organophosphate) and pirimicarb (carbamate).The proportion of aphids with probing duration longer than 1 min and which probed on the upper surface of the leaf were significantly higher in treatments with dimethoate (1000 mg a.i. 1⁻¹) and pirimicarb (1000 mg a.i. 1⁻¹) than with either cypermethrin at 100 and 150 mg a.i. 1⁻¹ or deltamethrin at 75 and 100 mg a.i. 1⁻¹. Treatment with cypermethrin and deltamethrin significantly increased the proportion of uninfected plants compared with dimethoate and pirimicarb.The number of aphid inoculations was lower in pyrethroid-treated plants than in dimethoate- and pirimicarb-treated ones. Therefore, aphids did not probe sufficiently to transmit CAMV in pyrethroid-treated plants.It is concluded that the pyrethroids have the potential to restrict virus transmission in the short term, while resistance breeding is in progress.     

A further prenatal diagnosis of mosaic tetrasomy 12p (Pallister-Killian syndrome)

A case of mosaic tetrasomy 12p was detected in amniotic fluid cell cultures from a 28-year-old woman referred to us at 26 weeks' gestation because of hydramnios. The fetus was shown on ultrasonography to have an omphalocele and a short femur length. Labour was induced at 32 weeks. An infant with multiple congenital anomalies was delivered and died after 10 min. The diagnosis of i(12p) or Pallister-Killian syndrome was confirmed cytogenetically in fibroblast and lymphocyte cultures. Increased LDH-B activity was demonstrated in fibroblasts.     

Prenatal diagnosis of mosaic trisomy 9

Mosaic trisomy 9 was detected in an amniotic fluid cell culture from a 40-year-old woman evaluated because of advanced maternal age. After counselling, parents elected to terminate the pregnancy. On autopsy the fetus was found to have hydrocephalus and a single kidney. The diagnosis of trisomy 9 mosaicism was confirmed in cultured skin fibroblasts. This is the third reported case of trisomy 9 mosaicism diagnosed prenatally.     

Prenatal management of mosaic tetrasomy 5p

An Erratum has been published for this article in Prenatal Diagnosis 2003; 23 (6): 521. No Abstract.     

Prenatal diagnosis of mosaic tetrasomy 5p

We report the prenatal diagnosis of a fetus with tetrasomy 5p mosaicism resulting from a supernumerary isochromosome for the short arm of chromosome 5. The pregnancy was terminated and fetal autopsy revealed minor facial abnormalities (long philtrum, up-slanting palpebral fissures and a broad nasal bridge). Cultures were established from fetal skin, kidney, and pancreas for cytogenetic analysis; the i(5p) was observed only in the skin fibroblasts. To our knowledge, this is the fourth report of mosaic tetrasomy 5p and the first report of prenatal diagnosis of this abnormality. Copyright © 2001 John Wiley & Sons, Ltd.     

A novel cell division factor from tobacco 2B-13 cells that induced cell division in auxin-starved tobacco BY-2 cells

Effects of auxin as plant hormones are widespread; in fact in almost all aspects of plant growth and development auxin plays a pivotal role. Although auxin is required for propagating cell division in plant cells, its effect upon cell division is least understood. If auxin is depleted from the culture medium, cultured cells cease to divide. It has been demonstrated in this context that the addition of auxin to auxin-starved nondividing tobacco BY-2 cells induced semisynchronous cell division. On the other hand, there are some cell lines, named habituated cells, that can grow without auxin. The cause and reason for the habituated cells have not been clarified. A habituated cell line named 2B-13 is derived from the tobacco BY-2 cell line, which has been most intensively studied among plant cell lines. When we tried to find the difference between two cell lines of BY-2 and 2B-13 cells, we found that the addition of culture filtrated from the auxin-habituated 2B-13 cells induced semisynchronous cell division in auxin-starved BY-2 cells. The cell division factor (CDF) that is responsible for inducing cell division in auxin-starved BY-2 cells was purified to near-homogeneity by sequential passage through a hydroxyapatite column, a ConA Sepharose column and a Sephadex gel filtration column. The resulting purified fraction appeared as a single band of high molecular weight on sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels by silver staining and was able to induce cell division in auxin-starved BY-2 cells. Identification of the protein by MALD-TOF-MS/MS revealed that it is structurally related to P-glycoprotein from Gossypioides kirkii, which belongs to ATP-binding cassette (ABC)-transporters. The significance of CDF as a possible ABC-transporter is discussed in relationship to auxin–autotrophic growth and auxin-signaling pathway.     

Pregnancy and postnatal outcome of mosaic isochromosome 20q

Prenatally diagnosed mosaicism for isochromosome 20q is generally reported in association with a normal outcome at birth and is rarely confirmed postnatally. However, the origin of these abnormal cells is unclear and there are few reports of long-term outcomes. We present an additional case of prenatally detected isochromosome 20q, with normal outcome up to age 3.6 years. The abnormal cells, while present at high levels in the amniotic fluid, could not be confirmed in placenta or fetal blood. Nonetheless, based on a review of the literature, the level of isochromosome 20q cells found is associated with risk of abnormal outcome, suggesting a possible effect in some cases. Copyright © 2006 John Wiley & Sons, Ltd.