高精度二维DCT的结构优化算法研究及FPGA实现

提出了一种基于5级流水线的高精度向量乘法器的二维DCT VLSI结构.采用一维DCT行处理,转置RAM存储器,一维DCT列处理的流水线结构代替复用一维DCT算法以提高速度,并且在一维DCT算法模块中,对于系数乘法,采用并行乘法的结构,可以进一步提高运算速度.在高精度方面,采用移位的方案,精度精确到小数点后5位,满足高精...     

百合多糖的药理作用研究进展

龙牙百合（Lilium brownii var. viridulum）是我国主要传统食用药用百合之一,本试验拟探究龙牙百合多糖提取工艺及其理化性质和功能活性,以龙牙百合鳞茎为原料,以多糖得率为指标,料液比、浸提时间和浸提温度为因素,对龙牙百合多糖提取工艺进行优化,再进一步去蛋白纯化多糖,分析其理化性质,测定其体外抗氧化和降血脂能力。结果显示：龙牙百合粗多糖最佳提取工艺为料液比1:20 g/mL,浸提时间20 min,浸提温度75 ℃,粗多糖得率为11.98%。粗多糖总糖、糖醛酸和蛋白质含量分别为58.46%、8.06%和10.85%,经过去蛋白后多糖的总糖和糖醛酸含量分别提高到84.78%和15.41%,蛋白质含量降低至4.73%。龙牙百合去蛋白多糖在10 mg/mL时对DPPH和ABTS⁺自由基清除率为8.75%和38.59%,低于对照V_C;对胰脂肪酶的抑制率为85.78%,高于对照奥利司他,有较好的体外抑制胰脂肪酶效果。实验结果将为进一步研究龙牙百合多糖的构效关系和开发具有潜力的功能性食品提供依据,并为百合的应用提供理论参考。     

Evidence of transmission of hepatitis B virus to spouses from sequence analysis of the viral genome

Despite advances in postnatal care, patients born with a congenital diaphragmatic hernia (CDH) suffer substantial morbidity and mortality. The present study was undertaken to determine the prognostic influence of prenatally-diagnosed liver herniation in the hemithorax in fetuses with CDH. The medical records of 48 patients evaluated for a prenatally-diagnosed left CDH were retrospectively reviewed. Patients were analysed according to the position of the liver by prenatal ultrasound; 32 fetuses had a major portion of the liver herniated into the left hemithorax ('liver up') and 16 had an intra-abdominal liver ('liver down'). Liver position was determined using colour-flow Doppler ultrasonography. There were two fetal deaths in the liver-up group and one in the liver-down group. The liver-up group more frequently required extracorporeal membrane oxygenation (ECMO) support (53 per cent) compared with the liver-down group (19 per cent). Postnatal survival was significantly less in the liver-up group (43 per cent) vs. the liver-down group (93 per cent). Fetuses with congenital diaphragmatic hernia and liver herniated into the hemithorax have a much worse prognosis than similarly afflicted fetuses without liver herniation. Prenatal ultrasonographic diagnosis of congenital diaphragmatic hernia allows for preparation for a critically ill newborn and aids in prenatal family counselling.     

Prospective randomized controlled trial of preservation of the intercostobrachial nerve during axillary node clearance for breast cancer

OBJECTIVE: The authors' goal was to determine whether cognitive behavioral treatment of residual symptoms of depression might have a significant effect on relapse rate. METHOD: A 6-year follow-up assessment was conducted of 40 patients with primary major depressive disorder who had been successfully treated with antidepressants and were randomly assigned to either cognitive behavioral treatment of residual symptoms or standard clinical management. RESULTS: Ten of the patients (50%) in the cognitive behavioral treatment group and 15 (75%) in the standard clinical management group relapsed. The difference did not attain statistical significance. When multiple relapses were considered, patients in the cognitive behavioral treatment group had a significantly lower number of depressive episodes than those in the standard clinical management group. Patients responded to the same antidepressant drug used in the index episode; in two cases (4%), resistance occurred. CONCLUSIONS: The protective effects of cognitive behavioral treatment that were evident at 4-year follow-up faded afterward. Cognitive behavioral treatment of residual symptoms, however, improved the long-term outcome of major depression in terms of total number of episodes during the follow-up period.     

Major depressive disorder: a prospective study of residual subthreshold depressive symptoms as predictor of rapid relapse

BACKGROUND: The study tested whether level of recovery from major depressive episodes (MDEs) predicts duration of recovery in unipolar major depressive disorder (MDD) patients. METHODS: MDD patients seeking treatment at five academic centers were followed naturalistically for 10 years or longer. Patients were divided on the basis of intake MDE recovery into residual depressive symptoms (SSD; N=82) and asymptomatic (N=155) recovery groups. They were compared on time to first episode relapse/recurrence, antidepressant medication, and comorbid mental disorders. Recovery level was also compared to prior history of recurrent MDEs ( > 4 lifetime episodes) as a predictor of relapse/recurrence. RESULTS: Residual SSD compared to asymptomatic recovery patients relapsed to their next MDE > 3 times faster (median=68 vs. 23 weeks) and to any depressive episode > 5 times faster (median=33 vs. 184 weeks). Residual SSD recovery status was significantly associated with early episode relapse (OR=3.65) and was stronger than history of recurrent MDEs (OR=1.64). Rapid relapse in the SSD group could not be attributed to higher comorbidity or lower antidepressant treatment. LIMITATIONS: Although inter-rater agreement on weekly depressive symptom ratings was very high (ICC > 0.88), some error may exist in assigning recovery levels. Antidepressant treatments were recorded, but were not controlled. CONCLUSIONS: MDE recovery is a powerful predictor of time to episode relapse/recurrence. Residual SSD recovery is associated with very rapid episode relapse which supports the idea that SSD is an active state of illness. Asymptomatic recovery is associated with prolonged delay in episode recurrence. These findings of this present study have important implications for the goals of treatment of MDD and for defining true MDE recovery.     

The diagnosis of microcirculatory-rheological disorders and their correction in patients with the initial manifestations of insufficiency of the cerebral blood supply

An evaluation was done of the state of bulbar microcirculation and aggregability of blood platelets in 47 patients presenting with early manifestations of cerebral circulatory insufficiency. A correlation was established between the revealed disturbances in the microcirculatory bed and augmentation of aggregational activity of thrombocytes. Computation of the integrative guide, microcirculatory-rheologic index, reflecting objectively the degree of intravascular hemocirculatory disorders has been performed. Treatment with calcium antagonist corinfar, antihypoxic agent actovegin was of particular benefit for the patients when administered in combination; more than half of the parameters characterizing microcirculation, rheologic properties of blood, microcirculatory-rheologic index have all returned to normal.     

Disulphide structure of a sunflower seed albumin: conserved and variant disulphide bonds in the cereal prolamin superfamily

Disulphide mapping of a methionine-rich 2S albumin from sunflower seeds showed four intra-chain disulphide bonds which are homologous with those in a related heterodimeric albumin from lupin seeds (conglutin delta). Similar conserved disulphide bonds are also present in alpha-gliadin and gamma-gliadin storage proteins of wheat, but a lower level of conservation is present in a further related group of proteins, the cereal inhibitors of alpha-amylase and trypsin. These differences may relate to the different functions of the proteins.     

飞航导弹自动驾驶仪智能PID控制

针对飞航导弹扇面发射和大空域机动飞行而引起的非线性时变等实际问题,根据飞航导弹弹道特性,运用智能控制理论及传统的反馈理论设计了一种基于专家系统的智能PID控制自动驾驶仪.仿真结果表明,所设计的自动驾驶仪具有良好的飞行品质和较高的精度,同时也具有更强的鲁棒性.