The Bogomolov multiplier B0 （G） of a finite group G is defined as the subgroup of the Schur multiplier consisting of the cohomology classes vanishing after restriction to all abelian subgroups of G. The triviality o...The Bogomolov multiplier B0 （G） of a finite group G is defined as the subgroup of the Schur multiplier consisting of the cohomology classes vanishing after restriction to all abelian subgroups of G. The triviality of the Bogomolov multiplier is an obstruction to Noether＇s problem. We show that if G is a central product of G1 and G2, regarding Ki ≤ Z（Gi）,i = 1,2, and θ ： G1 →G2 is a group homomorphism such that its restriction θ｜K1 ： K1 → K2 is an isomorphism, then the triviality of Bo（G1/K1）, Bo（G1） and B0（G2） implies the triviality of Bo（G）. We give a positive answer to Noether＇s problem for all 2-generator p-groups of nilpotency class 2, and for one series of 4-generator p-groups of nilpotency class 2 （with the usual requirement for the roots of unity）.展开更多
提出了1种基于0.18μm CMOS工艺的低压低功耗、宽锁定范围、低复杂度的2分频直接注入锁定分频器.该分频器采用Class-C的LC-tank架构来降低电源电压,同时改善LC振荡器的起振情况.此外还采用双端注入混频技术来扩大锁定范围.仿真结果表明...提出了1种基于0.18μm CMOS工艺的低压低功耗、宽锁定范围、低复杂度的2分频直接注入锁定分频器.该分频器采用Class-C的LC-tank架构来降低电源电压,同时改善LC振荡器的起振情况.此外还采用双端注入混频技术来扩大锁定范围.仿真结果表明该分频器有很好的混频性能,且分频器核心电路(不包括输出buffer)在800 m V电源电压下的功耗仅为0.91 m W.在注入信号的功率为0 d Bm时,该分频器在没有任何调谐单元时的锁定范围为6.4-8.5 GHz.展开更多
The scavenger receptor class B type I (SR-BI) is a high-density lipoprotein (HDL) receptor involved in reverse cholesterol transport. Some studies reported the association to be stronger in the presence of diabetes. T...The scavenger receptor class B type I (SR-BI) is a high-density lipoprotein (HDL) receptor involved in reverse cholesterol transport. Some studies reported the association to be stronger in the presence of diabetes. The full length gene encoding SR-BI is comprised in 13 exons that are alternatively spliced to produce two major transcripts: the full length SR-BI and the splice variant SR-BII, in which exon 12 is skipped. Considering that type 2 diabetes status is characterized by changes in the concentration of plasma lipids, modifications in lipoprotein size and composition, which may be important modulators of the SR-BI expression;the aims of the study were to examine the influence of SR-BI polymorphism (rs838895) on lipid profile and SR-BI mRNA expression in a population of diabetic patients living in Juana Koslay City. Blood samples were drawn from controls (n = 40) and Type 2 diabetic patients (n = 66) and DNA and total RNA were obtained. SR-BI mRNA expression was measured by RT-PCR and SR-BI polymorphism was detected by Tetra Primer ARMSPCR. Compared to controls, diabetic patients had higher fasting serum glucose, glycated hemoglobin, triglycerides, total cholesterol, lowdensity lipoprotein cholesterol, and lower highdensity lipoprotein cholesterol. SR-BI mRNA expression was lower in T2DM when compared to controls, suggesting that the hyperglycemia presents in T2DM patients down-regulates SR-BI mRNA expression. Interestingly, we found that decreased SR-BI expression resulted in markedly increased plasma LDL concentrations in T2DM subjects, and the overexpression of SRBII isoform is responsible for the markedly increased plasma LDL-c concentrations. The polymorphism (rs838895) did not modify the mRNA level of SR-BI in leucocytes from control and diabetic patients. This study provides novel evidence suggesting that hyperglycemia may affect reverse cholesterol transport by controlling SRBI expression in diabetic patients. LDL cholesterol levels are associated with low SR-BI mRNA expression in T2DM.展开更多
目的对混合牙列期与恒牙列早期安氏Ⅱ类2分类错下颌生长发育特点进行分析比较。方法研究样本包括95名安氏Ⅱ类2分类错青少年与75名正常青少年。对每个对象拍摄手腕骨片和头颅侧位片,进行X线片头影测量分析。结果混合牙列期到恒牙...目的对混合牙列期与恒牙列早期安氏Ⅱ类2分类错下颌生长发育特点进行分析比较。方法研究样本包括95名安氏Ⅱ类2分类错青少年与75名正常青少年。对每个对象拍摄手腕骨片和头颅侧位片,进行X线片头影测量分析。结果混合牙列期到恒牙列早期的变化如下。1)角度:对照组SNB、S-Ba-Go增大,Ar-Go-Me、SN-MP、NSGn减小;实验组SNB、Ar-Go-Me、Cd-Go-Me、SN-MP、S-Ar-Go、S-Ba-Go变化无显著性。实验组Y轴角、NSGn增大,对照组Y轴变化无显著性。2)颏部:实验组除了颏凹陷增大外,其余各项指标变化差异无统计学意义。对照组除颏曲度减小外,颏高、颏厚、颏凹陷、颏厚/颏高、SL、Pog to NB增大。3)线距:对照组Cd-Go、Gn-Cd、Go-Me、Ar-Pog、Ar-Go的生长量大于实验组。结论本研究提出的混合牙列期与恒牙列早期安氏Ⅱ类2分类错下颌的生长发育特点有助于临床医生治疗中作出合理的计划。展开更多
基金Supported by Grant No.RD-08-82/03.02.2016 of Shumen University
文摘The Bogomolov multiplier B0 （G） of a finite group G is defined as the subgroup of the Schur multiplier consisting of the cohomology classes vanishing after restriction to all abelian subgroups of G. The triviality of the Bogomolov multiplier is an obstruction to Noether＇s problem. We show that if G is a central product of G1 and G2, regarding Ki ≤ Z（Gi）,i = 1,2, and θ ： G1 →G2 is a group homomorphism such that its restriction θ｜K1 ： K1 → K2 is an isomorphism, then the triviality of Bo（G1/K1）, Bo（G1） and B0（G2） implies the triviality of Bo（G）. We give a positive answer to Noether＇s problem for all 2-generator p-groups of nilpotency class 2, and for one series of 4-generator p-groups of nilpotency class 2 （with the usual requirement for the roots of unity）.
文摘提出了1种基于0.18μm CMOS工艺的低压低功耗、宽锁定范围、低复杂度的2分频直接注入锁定分频器.该分频器采用Class-C的LC-tank架构来降低电源电压,同时改善LC振荡器的起振情况.此外还采用双端注入混频技术来扩大锁定范围.仿真结果表明该分频器有很好的混频性能,且分频器核心电路(不包括输出buffer)在800 m V电源电压下的功耗仅为0.91 m W.在注入信号的功率为0 d Bm时,该分频器在没有任何调谐单元时的锁定范围为6.4-8.5 GHz.
文摘The scavenger receptor class B type I (SR-BI) is a high-density lipoprotein (HDL) receptor involved in reverse cholesterol transport. Some studies reported the association to be stronger in the presence of diabetes. The full length gene encoding SR-BI is comprised in 13 exons that are alternatively spliced to produce two major transcripts: the full length SR-BI and the splice variant SR-BII, in which exon 12 is skipped. Considering that type 2 diabetes status is characterized by changes in the concentration of plasma lipids, modifications in lipoprotein size and composition, which may be important modulators of the SR-BI expression;the aims of the study were to examine the influence of SR-BI polymorphism (rs838895) on lipid profile and SR-BI mRNA expression in a population of diabetic patients living in Juana Koslay City. Blood samples were drawn from controls (n = 40) and Type 2 diabetic patients (n = 66) and DNA and total RNA were obtained. SR-BI mRNA expression was measured by RT-PCR and SR-BI polymorphism was detected by Tetra Primer ARMSPCR. Compared to controls, diabetic patients had higher fasting serum glucose, glycated hemoglobin, triglycerides, total cholesterol, lowdensity lipoprotein cholesterol, and lower highdensity lipoprotein cholesterol. SR-BI mRNA expression was lower in T2DM when compared to controls, suggesting that the hyperglycemia presents in T2DM patients down-regulates SR-BI mRNA expression. Interestingly, we found that decreased SR-BI expression resulted in markedly increased plasma LDL concentrations in T2DM subjects, and the overexpression of SRBII isoform is responsible for the markedly increased plasma LDL-c concentrations. The polymorphism (rs838895) did not modify the mRNA level of SR-BI in leucocytes from control and diabetic patients. This study provides novel evidence suggesting that hyperglycemia may affect reverse cholesterol transport by controlling SRBI expression in diabetic patients. LDL cholesterol levels are associated with low SR-BI mRNA expression in T2DM.
文摘目的对混合牙列期与恒牙列早期安氏Ⅱ类2分类错下颌生长发育特点进行分析比较。方法研究样本包括95名安氏Ⅱ类2分类错青少年与75名正常青少年。对每个对象拍摄手腕骨片和头颅侧位片,进行X线片头影测量分析。结果混合牙列期到恒牙列早期的变化如下。1)角度:对照组SNB、S-Ba-Go增大,Ar-Go-Me、SN-MP、NSGn减小;实验组SNB、Ar-Go-Me、Cd-Go-Me、SN-MP、S-Ar-Go、S-Ba-Go变化无显著性。实验组Y轴角、NSGn增大,对照组Y轴变化无显著性。2)颏部:实验组除了颏凹陷增大外,其余各项指标变化差异无统计学意义。对照组除颏曲度减小外,颏高、颏厚、颏凹陷、颏厚/颏高、SL、Pog to NB增大。3)线距:对照组Cd-Go、Gn-Cd、Go-Me、Ar-Pog、Ar-Go的生长量大于实验组。结论本研究提出的混合牙列期与恒牙列早期安氏Ⅱ类2分类错下颌的生长发育特点有助于临床医生治疗中作出合理的计划。
