The sequential dispersing results of aerial cluster bomb are discussed. The ballistic model and the mod- el for impact point distribution of bullets are established. The main factors influencing impact point distribut...The sequential dispersing results of aerial cluster bomb are discussed. The ballistic model and the mod- el for impact point distribution of bullets are established. The main factors influencing impact point distribution are analyzed by numerical simulation. And the feasibility of improving distribution effect through sequential dis- persing is validated. Sequential dispersion and optimized airdrop parameters can help to achieve better battle effec- tiveness.展开更多
Intraductal papillary mucinous neoplasm(IPMN)is an increasingly reported entity.Extensive pancreatic calcification is generally thought to be a sign of chronic pancreatitis,but it may occur simultaneously with IPMN le...Intraductal papillary mucinous neoplasm(IPMN)is an increasingly reported entity.Extensive pancreatic calcification is generally thought to be a sign of chronic pancreatitis,but it may occur simultaneously with IPMN leading to diagnostic difficulties.We report a case of a patient initially diagnosed with chronic calcifying pancreatitis who was later shown to have a malignant IPMN.This case illustrates potential pitfalls in the diagnosis of IPMN in the case of extensive pancreatic calcification as well as clues that may lead the clinician to suspecting the diagnosis.The possible mechanisms of the relation between pancreatic calcification and IPMN are also reviewed.展开更多
Chlorfluazuron is an insect growth regulator for controlling the major insect pests in crops. This paper describes the effects of sublethal doses (LD10:1.00 ng/larva; LD3o: 3.75 ng/larva) of chlorfluazuron on sper...Chlorfluazuron is an insect growth regulator for controlling the major insect pests in crops. This paper describes the effects of sublethal doses (LD10:1.00 ng/larva; LD3o: 3.75 ng/larva) of chlorfluazuron on spermatogenesis in the adults of the common cutworm, Spodoptera litura (F.). Chlorfluazuron was applied topically to the newly-ecdysed fifth-instars ofS. litura under laboratory conditions. The secondary spermatocytes, spermatids, elongated spermatocytes with mature sperm and eupyrene sperm bundles were present in testis of newly emerged, 1 and 2 day-old adults, but gradually decreased in their numbers in the controls. However, the spermatogonia were not present in newly emerged, 1 and 2 day-old adults. Moreover, primary spermatocytes were present (174 ± 4.0) in newly emerged adults, but not found in 1 and 2 day-old adults. In the testes of newly emerged LD10-treated adults, the numbers of eupyrene and apyrene sperm bundles were significantly reduced compared with controls, and even significantly reduced in LD30-treated adults compared with LDlo, however, their ratios were not affected. Moreover, the pattern of spermatogenesis was the same in LD10- and LD30-treated male adults compared with controls. Furthermore, numbers of developing spermatocytes were significantly reduced in the LD10 compared with controls, and even significantly reduced in LD30-treated male adults compared with LD10. In newly emerged adults, the width and length of elongated spermatocytes with mature sperm were significantly reduced in LDlo- and more significantly reduced in LD30-treated compared with controls of S. litura. In vas deferens of untreated pre- and newly emerged adult male, both eupyrene and apyrene sperm bundles were found, however, in treated pre-adult male, only apyrene sperm bundles and in treated newly emerged adult male, fe, w eupyrene and numerous apyrene sperm bundles were found. It is concluded that spermatogenesis was significantly affected by chlorfluazuron.展开更多
Spermatogenesis is a complicated and poorly understood process that relies on the precise regulation of the self-renewal and differentiation of spermatogonia. In many organisms, micro RNAs(mi RNAs) are involved in mul...Spermatogenesis is a complicated and poorly understood process that relies on the precise regulation of the self-renewal and differentiation of spermatogonia. In many organisms, micro RNAs(mi RNAs) are involved in multiple developmental processes as critical regulators of transcriptional and post-transcriptional gene silencing. This study investigated the expression pattern of mi RNAs in type B spermatogonia cells(BSc) and primary spermatocytes(PSc) of mice, using a high-throughput small RNA sequencing system. The results revealed that the expression levels of Let-7 family mi RNAs were remarkably high in both cell types. Furthermore, the expression levels of mi R-21, mi R-140-3p, mi R-103, mi R-30 a, mi R-101 b and mi R-99 b were decreased during the transformation from BSc to PSc. These mi RNAs target vital genes that participate in apoptosis, cell proliferation and differentiation, junction assembly and cell cycle regulation. These results highlight the indispensable role of mi RNAs in spermatogenesis.展开更多
基金Supported by the Independent Scientific Research of Nanjing University of Science and Technology(2011YBXM110)~~
文摘The sequential dispersing results of aerial cluster bomb are discussed. The ballistic model and the mod- el for impact point distribution of bullets are established. The main factors influencing impact point distribution are analyzed by numerical simulation. And the feasibility of improving distribution effect through sequential dis- persing is validated. Sequential dispersion and optimized airdrop parameters can help to achieve better battle effec- tiveness.
文摘Intraductal papillary mucinous neoplasm(IPMN)is an increasingly reported entity.Extensive pancreatic calcification is generally thought to be a sign of chronic pancreatitis,but it may occur simultaneously with IPMN leading to diagnostic difficulties.We report a case of a patient initially diagnosed with chronic calcifying pancreatitis who was later shown to have a malignant IPMN.This case illustrates potential pitfalls in the diagnosis of IPMN in the case of extensive pancreatic calcification as well as clues that may lead the clinician to suspecting the diagnosis.The possible mechanisms of the relation between pancreatic calcification and IPMN are also reviewed.
文摘Chlorfluazuron is an insect growth regulator for controlling the major insect pests in crops. This paper describes the effects of sublethal doses (LD10:1.00 ng/larva; LD3o: 3.75 ng/larva) of chlorfluazuron on spermatogenesis in the adults of the common cutworm, Spodoptera litura (F.). Chlorfluazuron was applied topically to the newly-ecdysed fifth-instars ofS. litura under laboratory conditions. The secondary spermatocytes, spermatids, elongated spermatocytes with mature sperm and eupyrene sperm bundles were present in testis of newly emerged, 1 and 2 day-old adults, but gradually decreased in their numbers in the controls. However, the spermatogonia were not present in newly emerged, 1 and 2 day-old adults. Moreover, primary spermatocytes were present (174 ± 4.0) in newly emerged adults, but not found in 1 and 2 day-old adults. In the testes of newly emerged LD10-treated adults, the numbers of eupyrene and apyrene sperm bundles were significantly reduced compared with controls, and even significantly reduced in LD30-treated adults compared with LDlo, however, their ratios were not affected. Moreover, the pattern of spermatogenesis was the same in LD10- and LD30-treated male adults compared with controls. Furthermore, numbers of developing spermatocytes were significantly reduced in the LD10 compared with controls, and even significantly reduced in LD30-treated male adults compared with LD10. In newly emerged adults, the width and length of elongated spermatocytes with mature sperm were significantly reduced in LDlo- and more significantly reduced in LD30-treated compared with controls of S. litura. In vas deferens of untreated pre- and newly emerged adult male, both eupyrene and apyrene sperm bundles were found, however, in treated pre-adult male, only apyrene sperm bundles and in treated newly emerged adult male, fe, w eupyrene and numerous apyrene sperm bundles were found. It is concluded that spermatogenesis was significantly affected by chlorfluazuron.
基金supported by the National Natural Science Foundation of China(81170616,81072093,30671092,81302323,31100915)the Natural Science Foundation of Hebei Province(C2014209140,C2009001260,C2012401039,H2013209194,C2013209024)the Scientific and Technical Supporting Programs of Hebei Province(10276109D)
文摘Spermatogenesis is a complicated and poorly understood process that relies on the precise regulation of the self-renewal and differentiation of spermatogonia. In many organisms, micro RNAs(mi RNAs) are involved in multiple developmental processes as critical regulators of transcriptional and post-transcriptional gene silencing. This study investigated the expression pattern of mi RNAs in type B spermatogonia cells(BSc) and primary spermatocytes(PSc) of mice, using a high-throughput small RNA sequencing system. The results revealed that the expression levels of Let-7 family mi RNAs were remarkably high in both cell types. Furthermore, the expression levels of mi R-21, mi R-140-3p, mi R-103, mi R-30 a, mi R-101 b and mi R-99 b were decreased during the transformation from BSc to PSc. These mi RNAs target vital genes that participate in apoptosis, cell proliferation and differentiation, junction assembly and cell cycle regulation. These results highlight the indispensable role of mi RNAs in spermatogenesis.