Cytogenetic characteristics of the leukemia L1210 strain in the development of drug resistance

The dose and schedule dependent resistance occurred at the 17th (L1210/D1) and 27th (L1210/D2) generations during leukemia L1210 transplantation by the cells treated with suboptimal diazane doses. With growth of the resistance to diazane the selection of modal cell class with 39 chromosomes took place while in the parent leukemia line the modal cell class consists of the cells with 40 chromosomes. No reliable differences were observed in G-banded karyotypes between the resistant subline L1210/D1 and the parent line L1210. When the resistant sublines were transplanted without supporting the diazane doses no restoration of the leukemic cells sensitivity to the drug was observed (the time of observation for L1210/D1 was 92 transplantation generations and for L1210/D2-48 generations). The changed number chromosome characteristics remained the same in this case.     

Sensitivity to chemotherapeutic preparations of anthracycline-resistant strains of murine leukemia P388

P388 leukemia strains resistant to rubomycin and ruboxylnitroxyl derivative of rubomycin were studied for their drug sensitivity. The resistant strains exhibited cross resistance to anthracycline antibiotics, vinca alkaloids, actinomycin D, colchicine. The rubomycin-resistant strain gained significantly higher sensitivity (in comparison with the parent strain and the ruboxyl-resistant strain) to six drugs: cisplatin, sarcolisin, dopan, thiophosphamide, degranol, 6-mercaptopurine. The karyotype of the ruboxyl-resistant cells was characterized by the presence of chromosome with homogeneously straining region (HSR). The alteration of the HSR-location was accompanied by the increase of chemotherapeutical sensitivity of the ruboxylresistant strain to the alkylating agents.     

Phosphorus-containing metabolites in the cells of anthracycline-resistant strains of leukemia P388

The method of 31P nuclear magnetic resonance has been used to study in vivo the level of phosphorus-containing metabolites in cells of two strains of murine leukemia P388 with the phenotype of the multidrug resistance and in cells of the parent strain. Cells of both resistant strains showed a depressed level of phosphomonoesters in comparison with the parent one. The influence of rubomycin and emoksil on the level of phosphorus-containing metabolites of drug-resistant and -sensitive strains has been evaluated. The drugs were established not to affect practically the pool of these metabolites of the resistant strains. Both drugs significantly increased the pool of phosphomonoesters in the parent strain cells.     

Characteristics of anthracycline-resistant strains of P388 leukemia

Two strains of P388 murine leukemia with acquired resistance to rubomycin (P388/rm) and its nitroxyl derivative ruboxyl (P388/rx). The rubomycin resistance has been developed by the 14th generation and ruboxyl one-by the 8th generation. The growth kinetic patterns and the cell cycle time of the parent and resistant strains were similar. An increased tumourogenicity of both resistant strains cells was found. The resistance development was accompanied by the appearance of the additional chromosome materials, namely of homogeneously staining region (P388/rx) and of double chromatin bodies (P388/rm). The partial recovery of sensitivity to rubomycin occurred during 36 generations (1 year). Simultaneously the genetic markers have been lost. The recovery of sensitivity to ruboxyl in this period was not observed. The obtained resistant strains possessed the multidrug resistance: the cross resistance of P388/rm and P388/rx to actinomycin D, Vinca alkaloids and colchicine was shown.     

一维光子晶体的应变测量

采用ZnSe和Na3AlF6两种经典介质材料构造一维光子晶体,缺陷层介质为Na3AlF6。利用传输矩阵法对带有缺陷的一维光子晶体的传光特性进行了理论分析,并得到其带隙特性。分别数值研究了参考光子晶体以及应变前后测量光子晶体的透射谱,分析结果表明光子晶体所受的纵向应变与其缺陷峰波长之间呈线性关系,根据这种对应关系提出了一种新的测量应变的方法。由于粘贴光子晶体的基底与光子晶体的线膨胀系数不同,且温度变化也会引起构成光子晶体材料折射率的变化,导致光子晶体透射谱缺陷峰波长的漂移。为了消除温度误差,在测量光路中设置了与测量光子晶体结构相同的参考光子晶体,对温度的影响进行了补偿。实验表明,测量系统的灵敏度为6×10-4nm/με,测量范围为0～2000με。     

Fabrication and characteristics of the nc-Si/c-Si heterojunction MAGFET

A MAGFET using an nc-Si/c-Si heterojunction as source and drain was fabricated by CMOS technology, using two ohm-contact electrodes as Hall outputs on double sides of the channel situated 0.7L from the source. The experimental results show that when V_(DS) = -7.0 V, the magnetic sensitivity of the single nc-Si/c-Si heterojunction magnetic metal oxide semiconductor field effect transistor (MAGFET) with an L : W ratio of 2 : 1 is 21.26 mV/T,and that with an L : W ratio of 4 : 1 is 13.88 mV/T. When the outputs of double nc-Si/c-Si heterojunction MAGFETs with an L : W ratio of 4 : 1 are in series, their magnetic sensitivity is 22.74 mV/T, which is an improvement of about 64% compared with that of a single nc-Si/c-Si heterojunction MAGFET.     

Enhanced antitumor action of 5-fluorouracil when used in combination with 4-methylmercaptopyrazolo[3,4-d]pyrimidine 1-nucleoside

Mice BDF1 with L 1210 or mice BALB/c with plasmacytoma MOPS-406 after pretreatment with ineffective doses of 1-beta-D-ribofuranosyl-4-methylmercaptopyrazolo(3,4-d)pyramidin e (25 to 100 mg/kg per 5 days) were treated with 5-fluorouracil at the optimal dose 100 mg per day. This combination produced a 1.5-2-fold or 2 to 4 fold enhancement of the antitumour effect of 5-fluorouracil without simultaneous increase of lethal toxicity.     

Compact-same-size 52- and 156 Mb/s SDH optical transceiver modules

Four types of compact SDH optical transceiver modules for intra- and interoffice transmission systems operating at 51.84- and 155.52-Mb/s have been incorporated with two types of packages, which are the same size for both bit rates. These modules contain both a transmitter and a receiver with a clock recovery function integrated in a single package. They were realized in the same size of L:50 mm×W:25 mm×H:8 mm (volume:10 cm³) and L:81 mm×W:31 mm×H:8 mm (volume:20-cm³) for intra- and interoffice system applications, respectively. The following technologies were used in their development: 1) three kinds of custom IC's were implemented using a 2-μm Si bipolar process, 2) surface-mounted SAW filters with the same size for both bit rates, and 3) high-density packaging technology to minimize receiver sensitivity degradation due to crosstalk noises. As a result, high receiver sensitivity of -43.2 and -42.7 dBm was achieved for 51.84-/s and 155.52-Mb/s interoffice transceiver modules with a wide dynamic range of over 30 dB. Also, in transceiver modules for intraoffice system applications, a receiver sensitivity of -37.7 and -31.7 dBm were obtained for both bit rates     

基于三维直方图降维和重建的快速最小误差阈值法

3维最小误差阈值分割法(3D-MET)的抗噪性很强,但计算复杂度非常高。其快速递推方法(3D-RMET)通过构建查找表去除了大量冗余操作,但其速度仍然不能满足实际工程要求。该文采用直方图降维和分级策略提出新的快速实现方法。该方法首先将3D-MET的最优阈值判别式进行分解,并给出新的阈值计算公式,将阈值搜索的空间维度从3维降到1维;然后将3维直方图进行分组和重建,进一步提高了算法处理速度。最后给出了3D-MET, 3D-RMET及本文方法的分割结果,并采用量化指标对结果进行对比分析。实验及量化对比结果表明,该文方法保持了原3D-MET法的强抗噪性,且将其时间复杂度降为O(L1/2)。与3D-RMET相比,该文方法快了6个数量级,较有效地解决了原方法时间复杂度高的问题。     

质子酸掺杂聚苯胺的制备及其常温气敏性能

以苯胺为单体,过硫酸铵为氧化剂,采用化学氧化聚合法,在酸性介质中合成了聚苯胺。并用FT-IR光谱和UV-Vis光谱对聚苯胺掺杂前后的结构变化进行了分析,研究了不同质子酸掺杂对聚苯胺气敏性能的影响。结果表明,经质子酸掺杂后的聚苯胺,在室温下对NH3具有较好的灵敏度,其中结果最好的1mol/LH2SO4掺杂的聚苯胺对500×10–6NH3的灵敏度达到了10.86。     

Design, Fabrication, and Evaluation of 2 and 3-Bit GaAs MESFET Analog-to-Digital Converter IC's

The analog-to-digital converter (A/D) is a critical component of a signal processing system. GHz-rate A/D's will be required in many future systems. While Si bipolar based A/D's can easily meet 4-6-bit resolution requirements, excessive power dissipation (1 W per bit) limits their operation to 100-400-MHz sampling rates. Recently, GaAs MES-FET's have demonstrated high frequency operation with relatively low power dissipation. This paper describes the design of 2- and 3-bit A/D's using GaAs MESFET's. Monolithic integrated A/D circuits were fabricated and successfully operated at gigahertz sampling rates. This sampling rate is the highest reported for any AD technology at room temperature. The power dissipation is 150-200 mW per bit. With further improvements in comparator sensitivity, the design can be extended to 4-bit A/D for GHz rate operation.     

Design, fabrication, and evaluation of 2- and 3-bit GaAs MESFET analog-to-digital converter IC's

the analog-to-digital converter (A/D) is a critical component of a signal processing system. GHz-rate A/D's will be required in many future systems. While Si bipolar based A/D's can easily meet 4-6-bit resolution requirements, excessive power dissipation (1 W per bit) limits their operation to 100-400-MHz sampling rates. Recently, GaAs MESFET's have demonstrated high frequency operation with relatively low power dissipation. This paper describes the design of 2- and 3-bit A/D's using GaAs MESFET's. Monolithic integrated A/D circuits were fabricated and successfully operated at gigahertz sampling rates. This sampling rate is the highest reported for any A/D technology at room temperature. The power dissipation is 150-200 mW per bit. With further improvements in comparator sensitivity, the design can be extended to 4-bit A/D for GHz rate operation.     

Improved bounds for the rate loss of multiresolution source codes

We present new bounds for the rate loss of multiresolution source codes (MRSCs). Considering an M-resolution code, the rate loss at the ith resolution with distortion D/sub i/ is defined as L/sub i/=R/sub i/-R(D/sub i/), where R/sub i/ is the rate achievable by the MRSC at stage i. This rate loss describes the performance degradation of the MRSC compared to the best single-resolution code with the same distortion. For two-resolution source codes, there are three scenarios of particular interest: (i) when both resolutions are equally important; (ii) when the rate loss at the first resolution is 0 (L/sub 1/=0); (iii) when the rate loss at the second resolution is 0 (L/sub 2/=0). The work of Lastras and Berger (see ibid., vol.47, p.918-26, Mar. 2001) gives constant upper bounds for the rate loss of an arbitrary memoryless source in scenarios (i) and (ii) and an asymptotic bound for scenario (iii) as D/sub 2/ approaches 0. We focus on the squared error distortion measure and (a) prove that for scenario (iii) L/sub 1/<1.1610 for all D/sub 2/相似文献   

Lowering Internal Friction of 0D–1D–2D Ternary Nanocomposite‐Based Strain Sensor by Fullerene to Boost the Sensing Performance

The development of strain sensors with both large strain range (>50%) and high gauge factor (>100) is a grand challenge. High sensitivity requires material to perform considerable structural deformation under tiny strain, whereas high stretchability demands structural connection or morphological integrity for materials upon large deformation, yet both features are hard to be achieved in one thin film. A new 0D–1D–2D ternary nanocomposite–based strain sensor is developed that possesses high sensitivity in broad working strain range (gauge factor 2392.9 at 62%), low hysteresis, good linearity, and long‐term durability. The skin‐mountable strain sensor, fabricated through one‐step screen‐printing process, is made of 1D silver nanowire offering high electrical conductivity, 2D graphene oxide offering brittle layered structure, and 0D fullerene offering lubricity. The fullerene constitutes a critical component that lowers the friction between graphene oxide–based layers and facilitates the sliding between adjacent layers without hurting the brittle nature of the nanocomposite film. When stretching, layer slippage induced by fullerene can accommodate partial applied stress and boost the strain, while cracks originating and propagating in the brittle nanocomposite film ensure large resistance change over the whole working strain range. Such high comprehensive performance renders the strain sensor applicable to full‐spectrum human motion detection.     

The Impact of Mismatch on the Performance of Coded Narrow-Band FM with Limiter/Discriminator Detection

The performance of uncoded narrow-band FM with limiter/discriminator (L/D) detection over the additive white Gaussian noise channel has received widespread attention [1]-[14] over the years both from simulation and analytical standpoints. By comparison, little or nothing has appeared in the literature for the performance of this modulation/demodulation technique when used together with coding/decoding. The purpose of this paper is to partially fill this void by considering the potential gain offered by the combination of convolutionally encoded narrow-band FM with L/D detection and Viterbi decoding. Both hard and soft decision decoding cases will be considered with some rather surprising differences between the performances of the two. In particular, it will be shown that a large departure exists from the 2 dB advantage traditionally associated with soft decision decoding which is explained in terms of the mismatch between the coding channel and the decoding metric peculiar to this modulation/demodulation technique.     

A wide-bandgap copolymer donor with a 5-methyl-4H-dithieno[3,2-e:2',3'-g]isoindole-4,6(5H)-dione unit

Wide-bandgap copolymer donors with fused-ring accept-or units (FAUs) present excellent performance in non-fullerene organic solar cells due to their complementary light-absorption with nonfullerene acceptors,deep the highest occupied molecular orbital (HOMO) levels and high hole mobilities[1-4].A bunch of FAU-based copolymer donors were developed in recent years,such as PM6[s],PM7[6],PBQx-TCI[7],PTQ10[8],PBQ6[9],P2F-EHp[10],D16[11],L1-S[12],D18[13,14]and D18-CI[1s,16].They delivered ＞16％ power conversion effi-ciencies (PCEs) in solar cells.To develop good FAUs is the key toward efficient FAU-based copolymer donors.A good FAU generally has a strong electron-withdrawing character that leads to a low HOMO level and a high open-circuit voltage(Voc),and a relatively large molecular plane that facilitates poly-mer stacking and enhances hole mobility.Recently,we de-veloped copolymer donors D18 and D18-CI by using dithi-eno[3',2':3,4;2",3":5,6]benzo[1,2-c][1,2,5]thiadiazole (DTBT)unit[13] (Fig.1(a)).Thanks to the strong electron-withdrawing property and the rigid and extended molecular plane of DTBT,D18 and D18-CI deliver outstanding PCEs up to 18.69％[13-16].The success of D18 polymers stimulated us to design more high-performance copolymer donors with nov-el FAUs.In this work,we designed a wide-bandgap copoly-mer donor P1 by using a fused-ring imide building block,5-methyl-4H-dithieno[3,2-e:2',3'-g]isoindole-4,6(5 H)-dione(MDTID).Compared with the thiadiazole moiety in DTBT,the imide moiety in MDTID is more electron-withdrawing.The density functional theory (DFT) calculations show that MDTID has deeper HOMO and the lowest unoccupied molecular orbit-al (LUMO) levels than DTBT,suggesting the stronger electron-accepting capability of MDTID (Fig.1(a)).DFT calculations also indicate that MDTID leads to a deeper HOMO for P1 than that of D18,thus benefiting Voc (Fig.S1).     

基于游标效应的高灵敏光纤温度和应变传感器

提出一种基于光纤Sagnac干涉仪(FSI)和偏振模干涉仪(PMI)级联结构的高灵敏光纤温度和应变传感器。FSI作为参考干涉仪,是将对温度、应变、弯曲及扭转不敏感的椭圆芯保偏光纤(ECPMF)引入到Sagnac环内制得的。PMI作为传感干涉仪,是对光纤起偏器与末端端面镀金的熊猫型保偏光纤(PMF)的快轴/慢轴以45°角进行熔接制得的。参考干涉仪的自由光谱区(FSR)易被调整为接近传感干涉仪的FSR,从而产生光学游标效应,实现灵敏度放大。实验结果表明:所设计的级联传感器的温度灵敏度达15.56 nm/℃,是单个PMI的11.12倍;应变灵敏度达154.04 pm/με,是单个PMI的11.81倍。所设计的传感器具有灵敏度高、制作简单、稳定性好等优点,在航空航天、工业生产等领域中具有广阔的应用前景。     

Test of switched-capacitor ladder filters using OBT

In this paper, a way to test switched-capacitors ladder filters by means of Oscillation-Based Test (OBT) methodology is proposed. Third-order low-pass Butterworth and Elliptic filters are considered in order to prove the feasibility of the proposed approach. A topology with a non-linear element in an additional feedback loop is employed for converting the Circuit Under Test (CUT) into an oscillator. The idea is inspired in some author's previous works (G. Huertas, D. Vázquez, A. Rueda, J.L. Huertas, Oscillation-based Test Experiments in Filters: a DTMF example, in: Proceedings of the International Mixed-Signal Testing Workshop (IMSTW'99), British Columbia, Canada, 1999, pp. 249–254; G. Huertas, D. Vazquez, E. Peralías, A. Rueda, J.L. Huertas, Oscillation-based test in oversampling A/D converters, Microelectronic Journal 33(10) (2002) 799–806; G. Huertas, D. Vázquez, E. Peralías, A. Rueda. J.L. Huertas, Oscillation-based test in bandpass oversampled A/D converters, in: Proceedings of the International Mixed-Signal Test Workshop, June 2002, Montreaux (Switzerland), pp. 39–48; G. Huertas, D. Vázquez, A. Rueda, J.L. Huertas, Practical oscillation-based test of integrated filters, IEEE Design and Test of Computers 19(6) (2002) 64–72; G. Huertas, D. Vázquez, E. Peralías, A. Rueda, J.L. Huertas, Testing mixed-signal cores: practical oscillation-based test in an analog macrocell, IEEE Design and Test of Computers 19(6) (2002) 73–82). Two methods are used, the describing function approach for the treatment of the non linearity and the root-locus method for analysing the circuit and predicting the oscillation frequency and the oscillation amplitude. In order to establish the accuracy of these predictions, the oscillators have been implemented in SWITCAP (K. Suyama, S.C. Fang, Users' Manual for SWITCAP2 Version 1.1, Columbia University, New York, 1992). Results of a catastrophic fault injection in switches and capacitors of the filter structure are reported. A specification-driven fault list for capacitors is also defined based on the sensitivity analysis. The ability of OBT for detecting this kind of faults is presented.     

Characterization of flowing blood optical property under various fibrinogen levels using optical coherence tomography

The feasibility of characterization of human blood fibrinogen levels using optical coherence tomography (OCT) was investigated. Three groups of blood samples were reconstituted of red blood cells: 1) phosphate-buffered saline; 2) plasma with its intrinsic fibrinogen removed and commercial fibrinogen added; and 3) native plasma with various fibrinogen levels (0-12?g/L). OCT signal slope (OCTSS) of blood was extracted from OCT depth-reflectivity profiles. Effects of hematocrit (HCT) and blood flow on OCTSS of the blood under various fibrinogen concentrations were also studied. The results of blood flowing at 5?mm/s showed that OCTSS of all the three groups at HCT of 40% decreases with the increasing fibrinogen concentration up to a certain level, i. e., >8, 6, and 4?g/L for groups 1, 2, and 3, respectively. The blood of group 2 at HCTs of 30%, 40%, and 50% had a rapid decrease in OCTSS in the range of fibrinogen concentration of 0-2, 0-6, and 0-10?g/L, respectively. OCTSS value of blood flowing at 2.5?mm/s was lower than that at 5?mm/s at each fibrinogen concentration. In conclusion, OCTSS has a strong correlation with plasma fibrinogen concentration, and has the potential to identify the abnormal level of human blood fibrinogen.