基于电荷分布的分裂指叉指换能器模型研究

普通单电极叉指换能器由于相邻两个电极反射的波会同相位加强,它的指边缘反射明显,从而在声表面波器件中形成电极内反射干扰。为了尽量减小这种二阶效应,可以采用分裂指叉指换能器(亦称双电极换能器)。该文从场理论出发,得到叉指表面电荷分布函数,通过对电荷分布函数进行傅里叶变换,得到分裂指叉指换能器的一种新的数学解析模型。它可以准确地反映考虑临近效应后分裂指叉指换能器基频和谐振频率响应。

扣带回前部破坏术治疗精神分裂症远期疗效分析

本文报道得到随访的14例精神分裂症病人,经扣带回前部破坏术后5年,疗效仍有57.1%,对焦虑抑郁组、思维障碍组和激活性组症状仍然有效,故此手术可作为现有治疗精神分裂症的一种方法。但手术指征宜严,仅对那些多种药物治疗确实无效的病人才考虑手术。

基于MSC双声路SAW器件的设计仿真平台

利用模块化设计思想,在Matlab编程环境下实现了基于多条耦合器双声路声表面波器件的设计仿真平台。为了提高MSC双声路SAW器件的性能,该平台将多条耦合器、分裂指及假指设计方案融合到器件设计中。多条耦合器不仅实现了两个变迹换能器传递函数的乘积,而且消除了体声波对器件性能的影响。假指消除了通过变迹换能器引起的波前畸变。分裂指可以最小化换能器内部的声波反射问题。通过一个频率为203.559MHz的基于多条耦合器双声路声表面波器件的设计和实际测试结果的对比分析,证明了该设计仿真平台不仅可以进行器件版图结构的设计和模拟,而且设计平台所得到的版图和数据可以用于器件的掩膜版制作和器件封装尺寸参考。另外,该仿真设计平台可以很好地实现对器件的脉冲特性、频率响应特性的模拟和仿真。

指浅屈腱分裂带重建A_4滑车的解剖基础与临床应用

解剖６只新鲜尸手，观察Ａ４滑车与指浅屈腱分裂带及其相互关系，设计了两种重建Ａ４滑车的方法：（１）双分裂带并列法，即将两条分裂带残端并列缝向对侧滑车残端及分裂带止点；（２）单分裂带环绕法，用一条分裂带环绕屈指深腱一圈半缝向对侧滑车残端及分裂带止点。解剖测试重建的Ａ４滑车与原滑车效能相同。自１９８７年，将上述两法用于临床１８例２０指，ＴＡＭ法评定，优１１指，良６指，可２指，差１指，优良率８５％。利用指浅屈腱分裂带止点与Ａ４滑车止点相邻近的解剖特点，将分裂带残端缝向对侧即可重建一个坚强而有效的Ａ４滑车。双分裂带法适应于指浅屈腱残端拟切除者。切断一条分裂带重建Ａ４滑车对指浅屈腱功能无显著影响。

Gastrointestinal stromal tumor presenting with prominent calcification

We present a rare case of a gastrointestinal stromal tumor (GIST) in the stomach with prominent calcifica-tion at presentation. A 61-year-old woman visited our hospital because of epigastric discomfort. A spherical calcified lesion with a diameter of about 30 mm was incidentally shown in the left upper quadrant on an abdominal X-ray. Computed tomography demonstrated that the tumor was growing from the upper gastric body, with calcification in the peripheral ring area. A laparoscopic partial gastrectomy was performed, and the resected specimen revealed a well-circumscribed tumor with exophytic growth from the gastric muscularis propria. Microscopic examination revealed spindle- shaped tumor cells with calcification and hemorrhage. Additionally, positive immunoreactivity of the tumor to KIT and CD34 and a low mitotic index resulted in the diagnosis of very low risk GIST. There are a few case reports of heavily calcified GIST, although solitary or punctate calcification of primary GIST has been reported in several case series. Dystrophic calcification of necrotic or degenerative tissue is the supposed cause of primary calcified GISTs. In contrast, appearance of calcification after administration of imatinib mesylate, which may be one indicator of disease response, is possibly caused by a different mechanism.

Laser Device for the Protection of Biological Objects from the Damaging Action of Ionizing Radiation

Laser irradiation device for the protection of biological objects from the action of ionizing radiation to be used in practice has been manufactured （invention patent RU 2 428 228 C2）. Research of the action of y-radiation itself as well as of the combined action of laser devices on survival, weight, skin and the general mitotic index of the bone marrow cells （mitotic index of all nucleus-containing cells of the bone marrow） of C57BL/6 experimental young mice was carried out. The mice were irradiated with ionizing （whole body irradiation） and laser radiation, separately one by one in a special frame device. Laser radiation in the dose 1 mJ/cm^2 irradiated only the back of a mouse, or both the back and the abdomen of mice. In case of combined irradiation of mice, the time interval between two types of irradiation did not exceed 30 min. First, the mice were exposed to y-radiation then to laser radiation. The method of the laser radiation-protection of biological subjects contributes to an increase in the viability of mice, prevents the damages of skin and also increases the mitotic activity of mice bone marrow cells.

Allelopathic Potential of Rice （Oryza sativa L.） Cultivars on Barnyard Grass （Echinochloa crus-galh~

Laboratory and greenhouse studies were conducted to assess the allelopathic potential of 12 rice cultivars on barnyard grass. Polyethylene glycol （PEG） was used to determine the influence of osmotic potential on the bioassay materials. Effect of different concentrations of stem, root, and leaf extracts of rice cultivars on seed germination, radicle and primary shoot length of barnyard grass seedlings, and rate of respiration of root pieces were investigated in the laboratory experiments. Shoot height and dry weight of weed stands were studied in the greenhouse, Also total peroxidase activity, chlorophyll pigment and mitotic index were determined. Results indicated that, among rice cultivars, Mehr, Tarom-mahali, G3, Nemat, and Shahpasand caused the most inhibition effects on investigated factors. Amol-3 showed the least negative effects on growth of seedlings and stands of barnyard grass. In laboratory, the Mehr cultivar demonstrated the maximum inhibitory effects by reducing barnyard grass seed germination percentage （88%）, radicle length （100%）, primary shoot length （83%）, and root respiration （85%） Cell division, expressed as mitotic index, was significantly reduced in the presence of rice aqueous extracts. Mehr cultivar had higher inhibitory effect on mitosis compared to Amol-3. In greenhouse, the same cultivar showed the maximum inhibitory effect by reducing barnyard grass height （45%） and dry weight （64%）. With increase in extract concentration, the inhibitory effect increased. Leaf extract from rice plants was more effective compared with the root and stem extracts. Comparison of rice cultivars and PEG indicated that any reduction in germination and growth of barnyard grass using rice extract concentrations of 5% and 10% must have been the result of allelochemicals in the extracts. Lower extract concentrations showed a more pronounced inhibitory effect in the laboratory as compared to the greenhouse studies. These results suggest that rice leaf extracts may be a source of natural herbicide.

Circadian Rhythm of Root＇s Apical Meristem Mitosis Cells of Soybean

The circadian rhythms of apical meristem mitosis cells of the two types of soybean were investigated： wild soybeans - Glycine max （L.） Merr. （G. hispida Max.）, G. soja Sieb., and Zucc （G, ussuriensis Reg. and Maack）; and the hybrids of their homozygous forms （F6）. Representatives of the initial kinds and interspecific hybrids for reproduction were grown up in comparable conditions. Seeds of a soybean were grown up at 24℃ in Petri cups in thermostat in darkness during winter. For research of mitotic meristem cages activity the tips of roots were fixed temporal by acetoalcohol （fractional fixing） from 1 p.m. till 12 a.m., further up to 12 p.m. each 60 minutes. Acetokarmin was used for preparing the coloring. For researching of mitotic indexes, there have been analyzed from 6 up to 10 thousand cells at each stage （during each moment of time： 01 hour, 02, 03 06 ... 12, 13 ... 18 hours and further）. Within a day （day ＋ night） in cells of root apical meristem, three mitosis ＂waves＂ in each of the investigated forms with an absolute starting point of rest at 12 p.m., with precisely expressed further periodicity were found out. Each of the investigated forms misses in character of wave processes, on a degree of increase and recession of mitosis waves, on the level of mitotic indexes. Maximal mitotic activity at all the investigated forms is noted at 6 and 12 a.m. and 6 p.m.

Mutagenic Effect of Three Invasive Species through Allium Cepa Bioassay

Invasive alien species are a global threat to biodiversity that affects protected areas around the world. The occupation of new environments by these plants is a problem to be solved and it is essential to investigate all the aspects that allow this successful to find solutions to this question, such as its mutagenic effects. Thus, this study aimed to evaluate the mutagenic effect of leaves extracts of Acacia mangium Willd, Artocarpus heterophyllus Lam and Eriobothrya japonica （Thunb.） Lindl through Allium cepa bioassay. For this, A. cepa seeds were submitted to continuous and discontinuous （acute and chronic） treatments in medium with water （negative control） or four concentration of each extract （1, 5, 10 and 50 mg/mL）. The mitotic index was affected at all concentrations of three extracts tested in all treatments, continuous and discontinuous. Aneugenic effects were not related to any treatment tested. E. japonica extract induced clastogenic effects at 1, 5 and 10 mg/mL in continuous treatment, 5 and 10 mg/mL in acute discontinuous treatment and at 10 mg/mL in chronic discontinuous treatment. Clastogenic effect was also observed at 10 mg/mL ofA. heterophyllus extract in continuous and acute discontinuous treatments.

Ontogeny of rat chondrocyte proliferation:studies in embryo,adult and osteoarthritic (OA) cartilage

The aim of this work was to study the ontogeny of chondrocyte cell division using embryo, adult and osteoarthritic(OA) cartilage. We searched for mitosis phases and performed a comparative evaluation of mitotic index, basic fibro-blast growth factor b (FGFb), transforming growth factor β1 (TGF-β1) receptors, cyclin dependent kinase (CDK1)and Cyclin-B expression in fetal, neonate, 3, 5, 8 weeks old rats and experimental OA. Our results showed that mitosisphases were observed in all normal cartilage studied, although, we found a decrease in mitotic index in relation to tissuedevelopment. No mitosis was detected in OA cartilage. We also found a statistical significant reduction in cell number inOA cartilage, compared with the normal tissue. Furthermore, FGFb and TGF-β1 receptors diminished in relation totissue development, and were very scarce in experimental OA. Western blot assays showed CDK-1 expression in allcases, including human-OA cartilage. Similar results were observed for Cyclin-B, except for 8 weeks, when it was notexpressed. Our results suggest that cell division seems to be scarce, if not absent within the OA cartilage studied.Nevertheless, the existence of factors essential for cell division leaves open the question concerning chondrocyteproliferation in OA cartilage, which is likely to be present in the early stages of the disease.

Experimental study of gemcitabine combination with radiation in vitro on a highly metastatic human ovarian cancer cell line HO-8910PM

Objective： The aim of the study was to investigate the mechanism of gemcitabine （GEM） combination with radiation on the high metastasis human ovarian cancer cell line （HO-8910PM）. Methods： Human ovarian cancer cell line HO- 8910PM was treated with different concentrations of gemcitabine for 24 h, then the cells were counted. In the study of GEM combination with radiation, an efficiency of colony formation was observed; the cell cycle and apoptosis were analyzed by flow cytometry; the experiment of depend on the time and its radio sensitivity were observed by using mitotic index with the cells for each 24, 48, 72 and 96 h after experiment. Results： It suggested that the GEM had an inhibition effect on the human ovarian cancer cell line. The alive cell numbers were decreased by following a height of GEM concentration. When GEM in combina- tion with a radiation, the suppression was significantly increased than that of single GEM therapy. The efficiency of colony formation was significantly lower, under this condition the cell could be arrested at G0-G1 phase and could be decreased to enter into the S phase; the apoptosis percentage could be significantly increased; especially, under the 4 Gy and 6 Gy doses the cell apoptosis was more obvious. GEM combination with radiation had depended on the time to the cells; mitotic index of the calls in combination group was observed significantly lower than that of single GEM therapy or single radiation, and this showed that it had an effect of radiosensitivity. Conclusion： The GEM has a significant growth inhibition on the human ovarian cancer cells, GEM combination with radiation could induce HO-8910PM cell occurred arrested and apoptosis. It has depended on the time and has a radiosensitivity effect. The result shows that it is a better method to treat the human ovarian cancer by using radiotherapy combined with gemcitabine.

Toxicity Screening of Water Sources in Flooded Agricultural Areas of Nen-Shkodra Lowland Using Allium cepa L. Assay

The reaction ofAllium cepa root tips to the presence of potential toxic chemicals was used to evaluate the cyto/genotoxic effects of some water sources of Nen-Shkodra lowland agricultural area after massive 2010-2011 flooding. MRL （Mean root length）, MI （mitotic index）, PI （phase index） and CA （chromosome abnormalities） endpoints of onion roots, grown in four water samples, were measured and compared with tap water and Cu solution 0.5 mg/L （negative and positive controls）. Inhibition of root growth, cell division and induction of mitotic and chromosomal aberrations were detected. The most polluted water sample caused MRL inhibition of 36%, MI decrease of 38%, and a considerable increase in chromosomal aberrations （7.8%） compared to the negative control. Most frequent CA types were： bridges and fragments, stickiness and C-metaphase. The results indicated a slight toxic tendency of analyzed natural waters, serving as an alert of environmental impact that chemical pollution had after flooding.

The Effect of Gnaphafium oxyphyllum var. natalie on Cancer and Blood Cells

Gnaphalium oxyphyllum DC is a medicinal plant whose common uses by Mexican people include the treatment of cancer. The toxicity of the aqueous and organic fractions as well as the aqueous decoction of G. oxyphyllum var. natalie F. J. Espinosa were assessed on three human cancer cell lines as well as in blood cells in healthy human lymphocyte cultures. Cytotoxic activity was assessed by the Sulforhodamine B method on HeLa （human cervical carcinoma）, T47D （human breast carcinoma） and 22Rvl （human prostate carcinoma cancer）. Colchicine was used as positive control. The decoction was also tested on lymphocytes from healthy donors through the mitotic index as biomarker. We used whole blood for these cultures and estimated the effect of the extract on platelets, leukocytes and erythrocytes. The aqueous decoction was cytotoxic （EDs0 〈 20 μg/mL） on the three cancer cell lines. The mitotic index in the exposed lymphocyte cultures did not significantly differ from the control nor the blood counts showed any difference between the experimental and control cultures. These results prove that the toxic effect of the aqueous decoction of G. oxyphyllum var. natalie is specific for cancer cell lines.

MAXIMUM POPULATION SIZES IN HOST-PARASITOID MODELS

We are concerned with the problem of characterizing the distribution of the maximum number of individuals alive during a fixed time interval in host-parasitoid models, which is shown to have a matrix exponential form. We present simple conditions on the rates of change of population sizes for the matrix exponential solution to be explicit or algo- rithmically tractable. A particularly appealing feature of our solution based on splitting methods is that it allows us to obtain global error control.

The effect of volatile components in oil on evolutionary character- istics of diamondoids during oil thermal pyrolysis

On the basis of the results of simulation experiments, now we better understand the contribution of high carbon number hydrocarbons to diamondoid generation during thermal pyrolysis of crude oil and its sub-fractions(saturated, aromatic, resin, and asphalene fractions). However, little is known about the effect of volatile components in oil on diamondoid generation and diamondoid indices due to the lack of attention to these components in experiments. In this study, the effect of volatile components in oil on diamondoid generation and maturity indices was investigated by the pyrolysis simulation experiments on a normal crude oil from the HD23 well of the Tarim Basin and its residual oil after artificial volatilization, combined with quantitative analysis of diamondoids. The results indicate that the volatile components(≤n C12) in oil have an obvious contribution to the generation of adamantanes, which occurs mainly in the early stage of oil cracking(Easy Ro<1.0%), and influences the variations in maturity indices of adamantanes; but they have no obvious effect on the generation and maturity indices of diamantanes. Therefore, some secondary alterations e.g., migration, gas washing, and biodegradation, which may result in the loss of light hydrocarbons in oil under actual geological conditions, could affect the identification of adamantanes generated during the late-stage cracking of crude oil, and further influence the practical application of adamantane indices.