Negative Differential Resistance of Au-MgB2-Au Nanoscale Junctions

The electron transport of linear atomic chain trodes was investigated by using the density Green＇s function method. We have calculated of MgB2 sandwiched between Au（100） elecfunctional theory with the non-equilibrium the corresponding cohesion energy and conductance of junctions in different distance. It is found that, at the equilibrium position, the Au-B bond-length is 1.90 A, the B-Mg bond-length is 2.22 A, and the equilibrium conductance is 0.51G0 （Go=2e^2/h）. The transport channel is almost formed by the π antibonding orbitals, which was made up of the Px and Py orbital electrons of B and Mg atoms. In the voltage range of -1.5 to 1.5 V, the junctions show the metallic behaviors. When the voltage is larger than 1.5 V, the current decreases gradually and then negative differential resistance appears almost symmetrically on both positive and negative bias.

Non-anthracycline-containing docetaxel and cyclophosphamide regimen is associated with sustained worse outcome compared with docetaxel, anthracycline and cyclophosphamide in neoadjuvant treatment of triple negative and HER2-positive breast cancer patients:

Objective： A previous study demonstrated that non-anthracycline-containing docetaxel plus cyclophosphamide（TC） regimen was inferior to docetaxel, anthracycline and cyclophosphamide（TAC） in neoadjuvant treatment of triple-negative breast cancer（TNBC） and human epidermal growth factor receptor-2-（HER2）-positive breast cancer in a short-term follow-up. Herein, long-term follow-up survival outcomes have been investigated.Methods： TNBC or HER2-positive patients were randomized to receive 6 cycles of TC or TAC neoadjuvant treatment. The primary endpoint was pathological complete remission（p CR）. Secondary endpoints included clinical response rate, event-free survival（EFS）, and overall survival（OS）.Results： A cohort of 96 patients consisted of 45 in TC and 51 in TAC arm. With a median follow-up period of53（range, 8-76） months, the patients achieving p CR post neoadjuvant chemotherapy exhibited superior EFS and OS than patients without p CR（P〈0.05）. TAC treatment resulted in consistently better EFS than TC treatment：the estimated 5-year EFS was 66.1% vs. 29.8%（P=0.002）. Moreover, the estimated 5-year OS was also in favor of TAC： 88.4% vs. 51.6%（P〈0.001）. Multivariable analysis demonstrated that the treatment regimen was an independent prognostic factor, and patients treated with TAC had a superior EFS [hazard ratio（HR）, 0.48; 95%confidence interval（95% CI）, 0.26-0.90; P=0.021] and OS（HR, 0.20; 95% CI, 0.08-0.60; P=0.003）.Conclusions： The updated long-term follow-up data demonstrated a sustained benefit in EFS and OS from anthracycline-containing TAC treatment, indicating that anthracycline is an essential and effective drug in this clinical trial.

Changes of Serum Insulin-like Growth Factor-2 Response to Negative Symptom Improvements in Schizophrenia Patients Treated with Atypical Antipsychotics

Accumulating evidence suggests that a disruption of early brain development,in which insulin-like growth factor-2(IGF-2)has a crucial role,may underlie the pathophysiology of schizophrenia.Our previous study has shown that decreased serum IGF-2 was correlated with the severity of psychopathology in patients with schizophrenia.Here we conducted a prospective observation trial to investigate the effects of atypical antipsychotics on serum IGF-2 level and its relationship with clinical improvements in schizophrenia patients.Thirty-one schizophrenia patients with acute exacerbation and 30 healthy individuals were recruited in this study.Psychiatric symptoms were assessed using the Positive and Negative Syndrome Scale(PANSS)and serum IGF-2 levels were determined using ELISA.We found that schizophrenia patients with acute exacerbation had lower serum IGF-2 levels than control individuals at baseline(P<0.05).After 2 months of atypical antipsychotic treatment,a significant improvement in each PANSS subscore and total score was observed in patients(all P<0.01),and the serum IGF-2 levels of patients were significantly increased compared with those at baseline(203.13±64.62 vs.426.99±124.26 ng/mL;t=−5.044,P<0.001).Correlation analysis revealed that the changes of serum IGF-2 levels in patients were significantly correlated with the improvements of negative symptoms(r=−0.522,P=0.006).Collectively,our findings demonstrated changes of serum IGF-2 response to improvements of negative symptoms in schizophrenia patients treated with atypical antipsychotics,suggesting that serum IGF-2 might be a treatment biomarker for schizophrenia.

Characterization of the negative thermal expansion material Zr_(1-x)Hf_xW_2O_8

The oxide ZrW_2O_8 displays unusual property of isotropic negative thermalexpansion in a large wide temperature range, which makes it have a number of important potentialapplications. The cubic Zr_(1-x)Hf_xW_2O_8 (x velence 0,0.3, 0.5, 0.7, and 1.0) were synthesized bystandard solid state reaction technique. The high and low temperature X-ray diffraction analysisindicate that the substitution of the Hf^(4+) for Zr^(4+) only leads to reducing the latticeconstants, and the changes of negative thermal expansion coefficients are not obvious. The linearexpansion coefficients of Zr_(1-x)Hf_xW_2O_8 (x velence 0,0.3, 0.5, 0.7, and 1.0) are about -6 X 10^(-6) K^(-1) in the temperature range of 298 to 973 K, while that of Zr_(0.5)Hf_(0.5)W_2O_8 is -9.6X 10^(-6) K_(-1) from 83 to 298 K. The phase transition temperatures from alpha-ZrW_2O_8 tobeta-ZrW_2O_8 structure were also determined by X-ray diffraction method. Thermogravimetric analysis(TGA) exhibits that Zr_(1-x)Hf_xW_2O_8 is not hygroscopic in air.

Influence of Negative Bias Voltage on the Mechanical and Tribological Properties of MoS_2/Zr Composite Films

MoS2/Zr composite films were deposited on the cemented carbide YT14 （WC＋14%TiC＋6%Co） by medium-frequency magnetron sputtered and coupled with multi-arc ion plated techniques.The influence of negative bias voltage on the composite film properties,including adhesion strength,micro-hardness,thickness and tribological properties were investigated.The results showed that proper negative bias voltage could significantly improve the mechanical and tribological properties of composite films.The effects of negative bias voltage on film properties were also put forward.The optimal negative bias voltage was -200 V under this experiment conditions.The obtained composite films were dense,the adhesion strength was about 60 N,the thickness was about 2.4 μm,and the micro-hardness was about 9.0 GPa.The friction coefficient and wear rate was 0.12 and 2.1×10-7 cm3/N·m respectively after 60 m sliding operation against hardened steel under a load of 20 N and a sliding speed of 200 rev·min-1.

Negative differential resistance and quantum oscillations in FeSb_2 with embedded antimony

We present a systematical study on single crystalline FeSb2 using electrical transport and magnetic torque measurements at low temperatures. Nonlinear magnetic field dependence of Hall resistivity demonstrates a multi-carrier transport instinct of the electronic transport. Current-controlled negative differential resistance(CC-NDR) observed in currentvoltage characteristics below ～ 7 K is closely associated with the intrinsic transition ～ 5 K of FeSb2, which is, however,mediated by extrinsic current-induced Joule heating effect. The antimony crystallized in a preferred orientation within the FeSb2 lattice in the high-temperature synthesis process leaves its fingerprint in the de Haas-Van Alphen(dHvA) oscillations, and results in the regular angular dependence of the oscillating frequencies. Nevertheless, possible existence of intrinsic non-trivial states cannot be completely ruled out. Our findings call for further theoretical and experimental studies to explore novel physics on flux-free grown FeSb_2 crystals.

Negative Thermal Expansion of the Dy_2Fe_(16)Cr Compound

Structural, thermal expansion, and magnetic properties of the Dy_2Fe_(16)Cr compound are investigated by means of x-ray diffraction and magnetization measurements. The Dy_2Fe_(16)Cr compound has a hexagonal Th_2Ni_(17)-type structure. There exists a negative thermal expansion resulting from a strong spontaneous magnetostriction in the magnetic state of the Dy_2Fe_(16)Cr compound. The average thermal expansion coefficient is-0.794 × 10^(-5)/K in the temperature range 292–407 K. The spontaneous magnetostrictive deformation and the Curie temperature are discussed.

Negative thermal expansion and phase transition of low-temperature Mg_(2)NiH_(4)

The negative thermal expansion(NTE) phenomenon is of great significance in fabricating zero thermal expansion(ZTE) materials to avoid thermal shock during heating and cooling. NTE is observed in limited groups of materials, e.g., metal cyanides, oxometallates, and metalorganic frameworks, but has not been reported in the family of metal hydrides. Herein, a colossal and continuous negative thermal expansion is firstly developed in the low-temperature phases of LT1-and LT2-Mg_(2)NiH_(4) between 488 K and 733 K from in-situ transmission electron microscope(TEM) video, with the volume contraction reaching 18.7% and 11.3%, respectively. The mechanisms for volume contraction of LT1 and LT2 phases are elucidated from the viewpoints of phase transformation, magnetic transition, and dehydrogenation, which is different from common NTE materials containing flexible polyhedra units in the structure. The linear volume shrinkage of LT2 in the temperature of 488-553 K corresponds to the phase transition of LT2→HT with a thermal expansion coefficient of -799.7 × 10^(-6) K^(-1) revealed by in-situ synchrotron powder X-ray diffraction. The sudden volume contraction in LT1 between 488 and 493 K may be caused by the rapid dehydrogenation of LT1 to Mg_(2)Ni. The revealed phenomenon in single composite material with different structures would be significant for preparing zero thermal expansion materials by tuning the fraction of LT1 and LT2 phases.

Chidamide Combined with Paclitaxel Liposome for the Treatment of Advanced HER2-negative Breast Cancer in Clinical Study

The purpose of this study was to investigate the efficacy and safety of chidamide combined with paclitaxel liposome in the treatment of advanced HER-2-negative breast cancer.First,41 patients with advanced HER-2-negative breast cancer who had received two chemotherapy regimens from May 2017 to November 2017 were randomly selected to receive chidamide combined with paclitaxel liposome treatment(observation group,n=20)or placebo combined with paclitaxel liposome treatment(control group,n=21).The treatment scheme of the observation group was oral chidamide 30mg twice a week for 2 months.In addition,on day 1,the patients were given paclitaxel liposome orally and intravenously administered with 175 mg/m2 for 1 cycle for 21 days and 3 cycles of chemotherapy.The treatment scheme of the control group was oral placebo 30 mg twice a week for 2 months.In addition,the method of paclitaxel liposome administration was the same as the observation group.The response rate(RR),disease control rate(DCR),and progression-free survival(PFS)were compared between the two groups.The results showed that all the 41 patients could be evaluated.In the observation group,CR5,PR7,SD5 and PD3 were obtained.RR was 60.0%and DCR was 85.0%.In the control group,CR3,PR3,SD5 and PD10 were obtained.RR was 28.6%and DCR was 52.4%.RR and DCR in the observation group were better than those in the control group,and the difference was statistically significant(P<0.05).The median PFS of the observation group was 5.2 months,longer than that of the control group(3.1 months,P<0.05).The main adverse reactions in the two groups were gastrointestinal reactions and bone marrow suppression,with grade 1~2 as the main ones.The incidence of leukopenia,thrombocytopenia and nausea and vomiting in the observation group was higher than that in the control group(P<0.05).Therefore,the chidamide combined with paclitaxel liposome is effective in the treatment of advanced HER-2-negative breast cancer,and the adverse reactions can be tolerated.

Ki67、P53、VEGF和C-erbB-2在乳腺癌组织中表达的相关性研究及其临床意义

背景与目的:细胞增殖抗原标记物(Ki67)为细胞增殖的一个重要生物学指标。本研究旨在探讨Ki67、P53、VEGF和C-erbB-2在乳腺癌组织中的表达及其与临床病理因素的相关性。方法:用免疫组化方法检测151例乳腺癌组织中Ki67和其他生物学指标的表达,并与临床病理因素进行相关性分析。结果:Ki67在乳腺癌组织中的阳性率为74.8%(113/151)。Ki67表达与乳腺癌临床分期有关(P<0.05),而与患者年龄、肿瘤大小、淋巴结转移状况无显著性相关(P>0.05);Ki67表达与P53、C-erbB-2表达呈正相关(P<0.05),而与VEGF表达无显著性相关;Ki67和VEGF的共表达与肿瘤大小和临床分期有关(P<0.05)。结论:Ki67阳性表达可作为评价乳腺癌发生、发展的生物学指标,联合VEGF检测更有助于乳腺癌临床分期的判断。

乳腺癌组织中C-erbB-2、nm23基因的表达及其预后的关系

目的探讨乳腺癌组织中C-erbB-2基因和nm23基因的表达与预后的关系。方法采用免疫组织化学S-P法检测298例乳腺癌C-erbB-2、nm23基因表达情况并与乳腺癌病理类型、发病年龄、临床分期、腋淋巴结转移情况及5a生存率之间的关系进行分析。结果C-erbB-2基因阳性率36.24%(108/298),nm23基因阳性率为58.05%(173/298);C-erbB-2和nm23基因的表达与肿瘤病理类型、发病年龄、临床分期无明显相关性(P>0.05);C-erbB-2基因表达与腋淋巴结转移呈正相关,与5a生存率呈负相关,nm23基因的表达与腋淋巴结转移呈负相关,与5a生存率呈正相关(P<0.05);C-erbB-2基因表达与nm23基因表达两者之间明显负相关(P<0.05)。结论联合检测乳腺癌组织中C-erbB-2和nm23基因表达可能成为预测、评估乳腺癌患者临床预后的标记物。

青年和绝经后女性乳腺癌c-erbB-2、p53、ER和PR受体表达及意义

目的 探讨青年和绝经后女性乳癌c erbB 2、p53、ER、PR的表达及意义。方法 采用SP法检测青年组 (13 1例 )与绝经组 (13 6例 )乳癌组织中各指标的表达及其与临床分期、腋淋巴结 (ALN )转移、3年无病生存率 (DFS)之间的关系。结果 c erbB 2阳性与临床分期、ALN转移相关 (P <0 .0 5) ,c erbB 2阳性者 3年DFS低于阴性者 (P <0 .0 5)。青年组c erbB 2、p53阳性率高、ER阳性率低 (P <0 .0 1) ,3年DFS低于绝经组 (P <0 .0 5)。结论 c erbB 2表达是乳腺癌预后重要指标 ,青年乳腺癌c erbB 2、p53阳性率高 ,ER阳性率低 ,3年DFS低 。

子宫内膜腺癌C-erbB-2COX-2过度表达的相关性分析

目的:研究C-erbB-2、COX-2在子宫内膜增生性病变和子宫内膜腺癌中的表达特点及其相关性。方法:应用免疫组织化学S-P法检测了20例正常增生期子宫内膜、23例单纯性子宫内膜增生、21例复杂性子宫内膜增生、43例非典型性子宫内膜增生、25例子宫内膜腺癌中C-erbB-2、COX-2的表达。结果:C-erbB-2和COX-2在各实验组中的阳性表达率:单纯性增生组为4.5%和9.1%,复杂性增生组为4.8%和14.3%,低级别非典型增生组为30.0%和25.0%,高级别非典型增生组为60.9%和52.4%,腺癌组为92.0%和91.7%;C-erbB-2、COX-2在各实验组间差异均有显著性(P=0.000)。C-erbB-2与COX-2在各组的表达水平呈显著正相关关系(P<0.01)。结论:C-erbB-2、COX-2可能在子宫内膜癌的发生发展中发挥重要的协同作用,两者联合检测对子宫内膜腺癌及癌前病变的鉴别诊断有较高的诊断价值。

胃粘膜癌变过程中幽门螺杆菌感染与p53,c-erbB-2基因表达的研究

目的探讨胃粘膜癌变过程中幽门螺杆菌（Ｈｅｌｉｃｏｂａｃｔｅｒｐｙｌｏｒｉ，Ｈｐ）感染与ｐ５３，ｃｅｒｂＢ２基因表达的关系．方法浅表性胃炎１６例，肠上皮化生２２例，异型增生１４例，早期胃癌１８例及进展期胃癌４０例作为研究对象．用ＷａｒｔｈｉｎＳｔａｒｙ银染色法检测Ｈｐ，用免疫组化Ｓｐ法检测ｐ５３和ｃｅｒｂＢ２的基因表达产物．结果Ｈｐ，ｐ５３，ｃｅｒｂＢ２在浅表性胃炎的检出率各为５００％，００％，００％；在肠上皮化生的检出率各为５９１％，２２７％，１３６％；在异型增生的检出率各为８５７％，６４３％，２８６％；在早期胃癌的检出率各为１６７％，３３３％，１１１％；在进展期胃癌的检出率各为５０％，５２５％，５５０％；在癌旁粘膜的Ｈｐ检出率为８６７％；在癌前病变中，Ｈｐ阳性组的ｐ５３，ｃｅｒｂＢ２表达率均高于Ｈｐ阴性组．结论Ｈｐ感染参与了胃癌前病变的发生与发展；Ｈｐ感染可引起野生型ｐ５３基因失活和ｃｅｒｂＢ２基因激活，从而导致胃粘膜的癌变．

survivin在乳腺癌中的表达及其与Ki-67和c-erbB-2表达的关系

目的观察凋亡抑制蛋白survivin在乳腺癌组织中的表达,及其与c-erbB-2、Ki-67增殖指数的相关性及临床病理意义。方法应用免疫组织化学SP法检测survivin在正常乳腺组织(20例)和乳腺癌组织(96例)中的表达以及Ki-67、c-erbB-2在乳腺癌组织中的表达。结果 survivin阳性表达乳腺癌的Ki-67增殖指数(35.32±21.28)%明显高于survivin阴性者(20.42±11.34)%,survivin表达与肿瘤细胞增殖呈正相关(P<0.01);survivin在乳腺癌组织中的阳性表达率为70.83%(68/96),正常乳腺组织未见survivin表达;survivin蛋白的表达与c-erbB-2的表达呈正相关(P<0.01);sur-vivin蛋白的表达与临床分期、淋巴结转移和5年生存率有关(P<0.05),与年龄、是否绝经、肿瘤大小和组织学分级均无关。结论 survivin不仅参与凋亡的调控,还促进了细胞增殖,在乳腺癌发生、发展中起重要作用,过度表达提示预后不良。

胃癌组织p53、c-erbB-2、p21和nm23基因表达及其与预后的关系

目的:探讨胃癌组织p53、cerbB2、p21和nm23联合基因产物表达检测对胃癌诊断、治疗及预后判断的价值。方法:应用免疫组化技术对123例手术切除胃癌组织标本中p53、cerbB2、p21和nm23基因产物表达进行测定。结果:高分化胃癌组p53表达阳性率38.0%(27/71),cerbB2为59.2%(42/71),p21为39.4%(28/711),nm23为71.8%(51/71),低分化胃癌组4种基因表达阳性率分别为46.2%(24/52)、36.5%(19/52)、69.2%(24/52)和34.6%(18/52);在非胃癌组织(胃、十二指肠溃疡、胃息肉、重度不典型增生胃炎胃镜标本)未见cerbB2、p21、nm23基因表达。p53、cerbB2、p21的表达与胃癌的分化程度、肿瘤浸润深度、肿瘤转移程度呈正相关(r=0.53,r=0.67,r=0.48,P<0.05);nm23的表达与胃癌的分化程度、肿瘤浸润深度、肿瘤转移程度呈负相关(r=-0.36,P<0.05)。结论:胃癌组织p53、cerbB2、p21、nm23基因表达检测在胃良恶性肿瘤鉴别、非手术临床分期的判断及指导临床治疗等方面具有一定价值,多基因表达检测对胃癌预后判断明显优于单基因表达检测。

大肠癌中EGFR、c-erbB-2及VEGF的表达与临床病理特征的关系

目的研究EGFR、c-erbB-2和VEGF在大肠癌中的表达及其与临床病理特征的关系。方法应用免疫组化Envision方法检测61例大肠癌组织中EGFR、c-erbB-2及VEGF的表达水平。以多重线性回归分析上述基因表达水平与临床病理特征的关系。结果61例大肠癌中EGFR、c-erbB-2和VEGF的阳性表达率分别为49.2%(30/60)、73.8%(45/61)和70.5%(43/61),多因素分析显示它们分别与肿瘤大小,淋巴结、肝脏转移及Dukes分期相关,而与病人的性别和年龄无关。结论EGFR、c-erbB-2及VEGF可作为临床判定大肠癌恶性程度及评估预后的指标,对指导术后化疗或靶向治疗具有一定的意义。

Dukes' A、B期结直肠癌c-erbB-2,EGFR和TGF-α表达与复发转移的关系

背景与目的:尽管病理分期是结直肠癌患者主要的预后指标,但目前的分期系统不足以预测Dukes' A、B期患者术后复发风险及指导辅助治疗。分子预后标志物有可能补充分期的不足,且能为基于肿瘤个体生物学特征的治疗决策提供依据。本研究旨在探讨Dukes' A、B期结直肠癌中c-erbB-2、表皮生长因子受体(epithelial growth factor receptor,EGFR)、转化生长因子α(transforming growth factor-α,TGF-α)表达与术后复发转移的关系。方法:收集中山大学肿瘤防治中心1989年～1999年间88例行根治性手术的结直肠腺癌病例,Dukes' A期26例,Dukes' B期62例,复发转移组和非复发转移组各44例。至少随访5年或随访至复发。应用免疫组化方法检测原发瘤组织中c-erbB-2、EGFR、TGF-α蛋白表达。结果:复发组c-erbB-2、EGFR、TGF-α过表达率分别为43.2%(19/44)、63.6%(28/44)、65.9%(29/44),非复发组阳性率分别为25.0%(11/44)、27.3%(12/44)、43.2%(19/44)。χ2检验提示复发组EGFR、TGF-α过表达率明显高于非复发组,但两组c-erbB-2过表达率无差异。复发组EGFR和TGF-α共同过表达率36.4%(16/44)显著高于非复发组11.4%(5/44)(χ2=7.568,P=0.006)。多因素分析显示EGFR表达与术后复发转移有关。结论:EGFR表达可能与Dukes’A、B期结直肠癌术后复发转移有关。

乳癖霜外用对乳腺增生模型大鼠乳腺组织病理形态学和AP-2α、C-erbB-2表达的影响

目的研究乳癖霜外用对乳腺增生模型大鼠乳腺组织病理形态学和AP-2α、C-erbB-2蛋白表达水平的影响。方法 36只大鼠随机分为正常对照组、疾病模型组、三苯氧胺软膏组、乳癖霜小、中、大剂量组。通过雌、孕激素联合制造乳腺增生病大鼠模型,造模的同时给予不同的药物进行干预。30 d后观察各组大鼠乳腺组织病理学和脏器系数的改变,放射免疫法检测各组大鼠血清性激素的水平,Western印迹法测定各组大鼠乳腺组织AP-2α蛋白的表达水平,免疫组化测定各组大鼠乳腺组织C-erbB-2蛋白的表达水平。结果乳癖霜外用能降低乳腺增生模型大鼠的乳头直径和高度,改善模型大鼠乳腺组织病理形态学改变,调节血清性激素水平,降低模型大鼠乳腺组织中转录因子AP-2α、癌基因C-erbB-2蛋白的表达水平,与模型组比较有统计学差异(P<0.01或P<0.05)。结论乳癖霜外用对乳腺增生模型大鼠有显著的疗效,其作用机制可能为调节血清性激素水平及调节大鼠乳腺组织转录因子AP-2α、原癌基因C-erbB-2蛋白的表达水平。