新型左旋棉酚纳米微球的制备及在体外抑制人前列腺癌PC-3细胞生长的研究

目的:研究负载左旋棉酚的单甲氧基聚乙二醇-马来酰亚胺(mPEG-mal)纳米微球的体外抗肿瘤活性,并对其机理进行探讨。方法:采用乳化-挥发法制备负载左旋棉酚的纳米微球,在人前列腺癌PC-3细胞及人前列腺细胞RWPE-1细胞株上分析空白微球的毒性,以MTT法、AO染色、透射电镜及半定量RT-PCR检测Bcl-2及Bak mRNA的表达等方法评价其在体外对前列腺癌细胞株PC-3的抗肿瘤活性,并与左旋棉酚裸药进行比较。结果:左旋棉酚载药微球对体外培养的前列腺癌细胞生长的抑制与裸药相似,并呈剂量-时间依赖性,纳米微球可以诱导PC-3细胞发生典型的凋亡形态学改变,使Bcl-2 mRNA表达水平降低,Bak mRNA表达水平升高,空白微球在高浓度时,对于肿瘤细胞系及人前列腺RWPE-1细胞株均无明显毒性。结论:左旋棉酚纳米微球具有良好的抗肿瘤活性,载体无毒,具有良好的生物相容性,能诱导前列腺癌细胞的体外凋亡,是一种具有潜力的抗肿瘤纳米药物。

新型左旋棉酚纳米微球的制备及性质研究

目的:以mPEG-mal(单甲氧基聚乙二醇-马来酰亚胺)为原料,制备负载左旋棉酚的高分子纳米微球,并全面考察其性质。方法:通过O/W乳化扩散/挥发法,制备负载左旋棉酚的纳米粒子,优化制备工艺并考察纳米粒子的形态、粒径分布、体外释药特性及稳定性等性质。结果:通过乳剂-挥发法制备的空白粒子呈规整的球形,载药粒子的粒径为(65.1±15.2)nm,左旋棉酚的平均载药量为(37.5±0.3)%。体外释放实验显示,载药粒子具有缓释特征,在12h、24h、10d分别释放7.2%、14.6%、87.7%,并且稳定性良好。结论:本研究制备的左旋纳米微球具有一定的缓释特征,具有良好的应用前景和价值。

长效干扰素抗肝纤维化的临床观察

目的:研究长效干扰素抗肝纤维化的临床疗效。方法:治疗组70例接受长效干扰素治疗;对照组55例未用长效干扰素治疗。结果:治疗组血清HBV-DNA阴转应答率为55.7%;对照组应答率为1.8%。抗肝纤维化4项治疗组降幅显著大于对照组,有应答者显著大于无应答者。结论:长效干扰素使患者血清肝纤维化指标显著下降,下降幅度应答者大于无应答者,长疗程者大于短疗程者;长效干扰素有明确的抗肝纤维化作用。

内镜下硬化剂注射治疗食管静脉曲张144例临床分析

目的:探讨内镜下硬化剂注射治疗食管静脉曲张的近期疗效。方法:采用多点少量注射和少点足量注射法。结果:72例多点少量注射法曲张静脉闭塞率占94.4%,治疗时间为26.2 d,无明显再出血及食管狭窄等并发症。72例少点足量注射法静脉闭塞率为75.0%,治疗时间为13.9 d,食管狭窄发生率为0.7%,硬化期间再出血占14.6%。结论:采用多点少量注射法曲张静脉闭塞率高,无明显再出血等并发症。

Amplitude analysis of the decays D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)

Using e^(+)e^(−)annihilation data corresponding to an integrated luminosity of 2.93 fb^(−1)taken at the center-of-mass energy√s=3.773 GeV with the BESIII detector,a joint amplitude analysis is performed on the decays D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η).The fit fractions of individual components are obtained,and large interferences among the dominant components of the decays D^(0)→a_(1)(1260)π,D^(0)→π(1300)π,D^(0)→ρ(770)ρ(770),and D^(0)→2(ππ)_(S)are observed in both channels.With the obtained amplitude model,the CP-even fractions of D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η)are determined to be(75.2±1.1_(stat).±1.5_(syst.))%and(68.9±1.5_(stat).±2.4_(syst.))%,respectively.The branching fractions of D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η)are measured to be(0.688±0.010_(stat.)±0.010_(syst.))%and(0.951±0.025_(stat.)±0.021_(syst.))%,respectively.The amplitude analysis provides an important model for the binning strategy in measuring the strong phase parameters of D^(0)→4πwhen used to determine the CKM angleγ(ϕ_(3))via the B^(−)→DK^(−)decay.

Observation of e^(+)e^(-)→pppñπ-+c.c.

Using data taken at 29 center-of-mass energies between 4.16 and 4.70 GeV with the BESⅢdetector at the Beijing Electron Positron Collider corresponding to a total integrated luminosity of approximately 18.8 fb^(-1),the process e^(+)e^(-)→pppñπ+c.c.is observed for the first time with a statistical significance of 11.5σ.The average Born cross sections in the energy ranges of(4.160,4.380)GeV,(4.400,4.600)GeV and(4.610,4.700)GeV are measured to be(21.5±5.7±1.2)fb,(46.3±10.6±2.5)fb and(59.0±9.4±3.2)fb,respectively,where the first uncertainties are statistical and the second are systematic.The line shapes of the pñ and ppπ^(-)invariant mass spectra are consistent with phase space distributions,indicating that no hexaquark or di-baryon state is observed.

Search for hidden-charm tetraquark with strangeness in e^(+)e^(−)→K^(+)D_(s)^(∗−) D^(∗0 )+ c.c.

We report a search for a heavier partner of the recently observed Z_(cs)(3985)^(-) state,denoted as Z_(cs)^('-),in the process e^(+)e^(−)→K^(+)D_(s)^(∗−) D^(∗0 )+ c.c.,based on e^(*)e^(-)collision data collected at the center-of-mass energies of √s=4.661,4.682 and 4.699 GeV with the BESIII detector.The Z_(cs)^('-) is of interest as it is expected to be a candidate for a hidden-charm and open-strange tetraquark.A partial-reconstruction technique is used to isolate K^(+)recoil-mass spectra,which are probed for a potential contribution from Z_(cs)^('-)→D_(s)^(∗−) D^(∗0 )+ c.c.We find an excess of Z_(cs)^('-)→D_(s)^(*-)-D^(*0)(c.c.)candidates with a significance of 2.1o,after considering systematic uncertainties,at a mass of(4123.5±0.7_(sat)±4.7_(syst.))MeV/c^(2).As the data set is limited in size,the upper limits are evaluated at the 90%confidence level on the product of the Born cross sections(σ^(Borm))and the branching fraction(B)of Z_(cs)^('-)→D_(s)^(*-)-D^(*0),under different assumptions of the Z_(cs)^('-) mass from 4.120 to 4.140 MeV and of the width from 10 to 50 MeV at the three center-of-mass energies.The upper limits of σ^(Born).B are found to be at the level of O(1)pb at each energy.Larger data samples are needed to confirm the Z_(cs)^('-) state and clarify its nature in the coming years.

Search for the weak decayψ(3686)→■+c.c.

Using(448.1±2.9)×10^(6)ψ(3686)for the weak baryonic decayψ(3686)→Λc+∑-+c.c..The analysis procedure is optimized using a blinded method.No significant signal is observed,and the upper limit on the branching fraction(B)ofψ(3686)→Λc+∑-+c.c.is set as 1.4×10^(-5)at the 90%confidence level.

Observations of the Cabibbo-Suppressed decays Λ_(c)^(+)→nπ+π^(0),nπ^(+)π^(-)π^(+) and the Cabibbo-Favored decay Λ_(c)^(+)→nK^(-)π^(+)π^(+)

Using electron-positron annihilation data samples corresponding to an integrated luminosity of 4.5 fb-1,collected by the BESⅢdetector in the energy region between 4599.53 MeV and 4698.82 MeV,we report the first observations of the Cabibbo-suppressed decaysΛ_(c)^(+)→nπ^(+)π^(0),Λ_(c)^(+)→nπ^(+)π^(-)π^(+),and the Cabibbo-favored decayΛ_(c)^(+)→nK^(-)π^(+)π^(+)with statistical significances of 7.9σ,7.8σ,and>10σ,respectively.The branching fractions of these decays are measured to be B(Λ_(c)^(+)→nπ^(+)π^(0))=(0.64±0.09±0.02)%,B(Λ_(c)^(+)→nπ^(+)π^(-)π^(+))=(0.45±0.07±0.03)%,and B(Λ_(c)^(+)→nK^(-)π^(+)π^(+))=(1.90±0.08±0.09)%,where the first uncertainties are statistical and the second are systematic.We find that the branching fraction of the decayΛ_(c)^(+)→nπ^(+)π^(0)is about one order of magnitude higher than that ofΛ_(c)^(+)→nπ^(+).

Measurement of integrated luminosities at BESⅢ for data samples at center-of-mass energies between 4.0 and 4.6 GeV

The integrated luminosities of data samples collected in the BESⅢ experiment in 2016-2017 at centerof-mass energies between 4.19 and 4.28 GeV are measured with a precision better than 1% by analyzing large-angle Bhabha scattering events.The integrated luminosities of old datasets collected in 2010-2014 are updated by considering corrections related to detector performance,offsetting the effect of newly discovered readout errors in the electromagnetic calorimeter,which can haphazardly occur.

Luminosities and energies of e^(+)e^(−) collision data taken between √s=4.61 GeV and 4.95 GeV at BESⅢ

From December 2019 to June 2021,the BESⅢ experiment collected approximately 5.85 fb^(−1) of data at center-of-mass energies between 4.61 and 4.95 GeV.This is the highest collision energy BEPCⅡ has reached to date.The accumulated e^(+)e^(−) annihilation data samples are useful for studying charmonium(-like)states and charmed-hadron decays.By adopting a novel method of analyzing the production of A_(c)^(+)A_(c)^(-) pairs in e^(+)e^(−) annihilation,the center-of-mass energies are measured with a precision of 0.6 MeV.Integrated luminosities are measured with a precision of better than 1% by analyzing the events of large-angle Bhabha scattering.These measurements provide important inputs to analyses based on these data samples.

Observation of the Y(4230)and a new structure in e^(+)e^(-)→K^(+)K^(-)J/Ψ

The cross sections of e^(+)e^(-)→K^(+)K^(-)J/Ψat center-of-mass energies from 4.127 to 4.600 GeV are measured based on 15.6 fb-1data collected with the BESⅢ detector operating at the BEPCⅡ storage ring.Two resonant structures are observed in the line shape of the cross sections.The mass and width of the first structure are measured to be(4225.3±2.3±21.5)MeV and(72.9±6.1±30.8)MeV,respectively.They are consistent with those of the established Y(4230).The second structure is observed for the first time with a statistical significance greater than 8σ,denoted as Y(4500).Its mass and width are determined to be(4484.7±13.3±24.1)MeV and(111.1±30.1±15.2)MeV,respectively.The first presented uncertainties are statistical and the second ones are systematic.The product of the electronic partial width with the decay branching fractionΓ(Y(4230)→e^(+)e^(−))B(Y(4230)→K^(+)K^(−)J/Ψ)is reported.