Spinel compounds are of great interest in both fundamental and application-oriented perspectives due to the geometric magnetic frustration inherent to their lattice and the resulting complex magnetic states.Here,we ap...Spinel compounds are of great interest in both fundamental and application-oriented perspectives due to the geometric magnetic frustration inherent to their lattice and the resulting complex magnetic states.Here,we applied x-ray diffraction,magnetization,heat capacity and powder inelastic neutron scattering measurements,along with theoretical calculations,to study the exotic properties of chromite-spinel oxides CoCr_(2)O_(4) and MnCr_(2)O_(4).The temperature dependence of the phonon spectra provides an insight into the correlation between oxygen motion and the magnetic order,as well as the magnetoelectric effect in the ground state of MnCr_(2)O_(4).Moreover,spin-wave excitations in CoCr_(2)O_(4) and MnCr_(2)O_(4) are compared with Heisenberg model calculations.This approach enables the precise determination of exchange energies and offers a comprehensive understanding of the spin dynamics and relevant exchange interactions in complicated spiral spin ordering.展开更多
目的研究氟尿嘧啶植入剂(中人氟安,Sinofuan)和注射液对胃癌细胞腹腔播散化疗疗效的差异及其机制.方法♀BALB/c(nu/nu)裸鼠,每只腹腔注射0.5 m L(含2×106个)MKN-45细胞悬液建立裸鼠腹膜移植瘤模型.选取51只成瘤裸鼠,随机数字法分...目的研究氟尿嘧啶植入剂(中人氟安,Sinofuan)和注射液对胃癌细胞腹腔播散化疗疗效的差异及其机制.方法♀BALB/c(nu/nu)裸鼠,每只腹腔注射0.5 m L(含2×106个)MKN-45细胞悬液建立裸鼠腹膜移植瘤模型.选取51只成瘤裸鼠,随机数字法分为对照组、氟尿嘧啶注射液组(2 mg/只)和氟尿嘧啶植入剂组(2 mg/只).严密观察各组裸鼠的一般状态、体质量变化和生存期,测量腹水体积,显微镜下计数每毫升腹水中的肿瘤细胞数,流式细胞仪检测腹水肿瘤细胞凋亡率.结果与对照组相比,氟尿嘧啶注射液组和氟尿嘧啶植入剂组裸鼠的一般状态良好,体质量增长缓慢,全身症状出现较晚,生存期延长(与对照组相比,均P<0.05),其中,氟尿嘧啶植入剂组中位生存期较氟尿嘧啶注射液组亦延长(25 d vs 19 d,P<0.01).氟尿嘧啶植入剂组的腹水体积少于氟尿嘧啶注射液组[(5.66 mL±1.00 mL)vs(8.78 mL±1.19 mL),P<0.01];但两组每毫升腹水中的肿瘤细胞数差异无统计学意义[(2.75×108/m L±0.71×108/m L)vs(3.46×108/mL±0.69×108/mL)].氟尿嘧啶植入剂组的肿瘤细胞凋亡率高于氟尿嘧啶注射液组(14.49%±0.80%vs 2.03%±0.64%,P<0.01).结论氟尿嘧啶植入剂对胃癌腹腔播散有更明显的抑制作用.展开更多
通过以支链淀粉为碳源的初筛分离培养和以普鲁兰糖为惟一碳源的鉴别复筛,从浓香型烤烟根际土壤中分离到一株具有产普鲁兰酶活性的菌株,编号为CLM2。通过形态特征、生化特性和16S r DNA序列分析及系统发育进化树的构建,确定CLM2隶属于芽...通过以支链淀粉为碳源的初筛分离培养和以普鲁兰糖为惟一碳源的鉴别复筛,从浓香型烤烟根际土壤中分离到一株具有产普鲁兰酶活性的菌株,编号为CLM2。通过形态特征、生化特性和16S r DNA序列分析及系统发育进化树的构建,确定CLM2隶属于芽孢杆菌属(Bacillus),暂命名为Bacillus sp.CLM2。在以玉米淀粉为碳源、35℃、180 r/min条件下的发酵历程中,发酵54 h时普鲁兰酶活力达到最大值,为4.3 U/m L。展开更多
基金the financial support from the National Key Research and Development Program of China(Grant No.2022YFA1402702)the National Science Foundation of China(Grant Nos.U2032213 and 12004243)+8 种基金the National Science Foundation of China(Grant No.12274412)the Interdisciplinary Program of Wuhan National High Magnetic Field Center(Grant No.WHMFC 202122)Huazhong University of Science and Technologythe support from the National Natural Science Foundation of China(Grant No.52101236)Guangdong Basic and Applied Basic Research Foundation(Grant No.2021B1515140014)the Guangdong Provincial Key Laboratory of Extreme Conditionsfinancial support from the National Key Research and Development Program of China(Grant Nos.2021YFA1600201 and 2023YFA1607402)the support of NSF-DMR-2003117supported by a beamtime allocation RB1910163 from the Science and Technology Facilities Council。
文摘Spinel compounds are of great interest in both fundamental and application-oriented perspectives due to the geometric magnetic frustration inherent to their lattice and the resulting complex magnetic states.Here,we applied x-ray diffraction,magnetization,heat capacity and powder inelastic neutron scattering measurements,along with theoretical calculations,to study the exotic properties of chromite-spinel oxides CoCr_(2)O_(4) and MnCr_(2)O_(4).The temperature dependence of the phonon spectra provides an insight into the correlation between oxygen motion and the magnetic order,as well as the magnetoelectric effect in the ground state of MnCr_(2)O_(4).Moreover,spin-wave excitations in CoCr_(2)O_(4) and MnCr_(2)O_(4) are compared with Heisenberg model calculations.This approach enables the precise determination of exchange energies and offers a comprehensive understanding of the spin dynamics and relevant exchange interactions in complicated spiral spin ordering.
