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991.
Takei H  Ruiz B  Dancer J  Hicks J 《Acta cytologica》2007,51(5):692-698
OBJECTIVE: To compare the cytologic findings and diagnoses of breast fine needle aspiration (FNA) samples of well-defined lesions (WDL) with those of poorly defined indurated lesions. STUDY DESIGN: We examined 371 consecutive breast FNA specimens obtained without diagnostic image guidance. Fifty-eight lesions were described by the examining pathologists as PDILs, and the remaining 313 lesions were described as WDLs. RESULTS: Compared with WDLs, PDILs were more likely to yield hypocellular specimens deemed unsatisfactory for diagnostic evaluation (37.9% vs. 14.1%). However, a substantial number of atypical, suspicious for malignancy and malignant cases (12.1%, 5.2%, and 13.8%, respectively) were identified with PDILs. In addition, benign diagnoses were more frequently rendered with aspirates of WDLs, compared with PDILs (47.9% vs. 31.0%). In our study, FNAs of PDILs were more often diagnostic in white women < 49 years of age and in lesions measuring > 2 cm. CONCLUSION: Given the relatively high frequency of malignant, suspicious and atypical lesions detected with PDILs, FNA is a suitable first diagnostic approach for PDILs, especially considering the relatively low cost and simplicity of FNA procedures without diagnostic imaging guidance.  相似文献   
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CsRCA超表达黄瓜株系T1-7、T1-2和野生型‘08-1’为试材,在三叶一心时用光照培养箱模拟高温环境[40 ℃,光量子通量密度(PFD) 600 μmol·m-2·s-1],研究了CsRCA超表达对高温胁迫下黄瓜幼苗光合作用的调控机理.结果表明: CsRCA超表达可显著提高转基因黄瓜幼苗核酮糖-1,5-二磷酸羧化/加氧酶(Rubisco)大、小亚基的mRNA 表达量,Rubisco和Rubisco活化酶(RCA)活性亦显著高于野生型植株.高温胁迫2 h后,超表达和野生型黄瓜幼苗的光合速率(Pn)、以吸收光能为基础的光化学性能指数(PIABS)、Rubisco活性和RCA活性及其mRNA表达量均显著降低.经JIP-test分析发现,高温胁迫导致叶绿素荧光快速诱导动力学曲线中K点明显上升, 而捕获的激子将电子传递到电子传递链中QA下游的其他电子受体的概率(Ψo)和用于电子传递的产额(φE0)均显著下降,说明PSⅡ放氧复合体(OEC)和QA之后的电子传递链在高温下受到抑制,但是超表达植株的变化幅度要小于野生型植株.可见CsRCA超表达可以通过提高Rubisco、RCA和PSⅡ活性,缓解高温对黄瓜幼苗光合作用的影响,增强其对高温的适应性.  相似文献   
997.
萃取-结晶法制备辣椒碱类化合物工艺研究   总被引:1,自引:0,他引:1  
为开发一条从辣椒精制备辣椒碱类化合物的工艺路线,考察了皂化、萃取和结晶条件对辣椒碱类化合物收率和纯度的影响,获得了纯化辣椒碱类化合物的最佳工艺条件:5%氢氧化钠溶液皂化辣椒精,皂化液酸化后用乙醚萃取2次,乙醚相用氢氧化钠水溶液萃取3次,所得氢氧化钠萃取液调pH值后结晶,得到辣椒碱类化合物,纯度为98.73%,总收率为78.89%.  相似文献   
998.
For decades, ecologists have investigated the effects of tree species diversity on tree productivity at different scales and with different approaches ranging from observational to experimental study designs. Using data from five European national forest inventories (16,773 plots), six tree species diversity experiments (584 plots), and six networks of comparative plots (169 plots), we tested whether tree species growth responses to species mixing are consistent and therefore transferrable between those different research approaches. Our results confirm the general positive effect of tree species mixing on species growth (16% on average) but we found no consistency in species‐specific responses to mixing between any of the three approaches, even after restricting comparisons to only those plots that shared similar mixtures compositions and forest types. These findings highlight the necessity to consider results from different research approaches when selecting species mixtures that should maximize positive forest biodiversity and functioning relationships.  相似文献   
999.
陕北沙地3种典型灌木根木质部解剖结构及水力特性   总被引:1,自引:0,他引:1  
比较了陕北沙地沙柳、柠条和沙棘3种典型灌木不同土壤深度(0~20和30~50 cm)根木质部解剖结构和水力特性.结果表明: 沙柳具有较高的叶水势,根木质部导管平均最大直径(dmax)、平均最小直径(dmin)、平均导管面积(Alum)以及导管面积占木质部面积比例(Aves/Axyl)显著高于柠条和沙棘,根导管密度(VD)与沙棘相当但显著高于柠条;沙柳根的比导水率分别为柠条和沙棘的5.0和2.8倍;沙柳根栓塞脆弱性指数与柠条根相当,但显著高于沙棘根.表明沙柳属耗水型水分利用策略,而柠条和沙棘属节水型水分利用策略,且柠条更耐旱.3种灌木在2个土层深度的dmax、dmin和Alum无显著差异,但30~50 cm土层根VD和Aves/Axyl显著高于表层;30~50 cm土层根比导水率显著高于表层根,但脆弱性指数小于表层根,深层根具有高的水分传输效率和低的水力脆弱性.  相似文献   
1000.
Dendritic cells (DCs) play an essential role in the induction of immune responses to pathogen infections. Native DCs are difficult to obtain in large numbers and consequently the vast majority of DCs employed in all experiments are derived from bone marrow progenitors. In an attempt to solve this problem, we have established a novel CD8alpha(+) DC line (H-2(k)) from spleen, which we have named SRDC line, and which is easy to culture in vitro. These cells display similar morphology, phenotype and activity to CD4(-)CD8alpha(+)CD205(+)CD11b(-) DCs purified ex vivo. Toxoplasma gondii antigen was shown to be taken up by these cells and to increase class I and class II major histocompatibility complex (MHC), CD40, CD80 and CD86 surface expression. We report that vaccination with T. gondii antigen-pulsed SRDCs, which synthesize large amounts of interleukin-12, induced protective immune responses against this intracellular pathogen in syngeneic CBA/J mice. This protection was associated with strong cellular and humoral immune responses at systemic and intestinal levels. Spleen and mesenteric lymph node cell proliferations were correlated with a Th1/Th2-type response and a specific SRDC homing to spleen and intestine was observed. The SRDC or CD4(-)CD8alpha(+)CD205(+)CD11b(-) DC line can be expected to be a very useful tool for immunobiology studies of DC.  相似文献   
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