New halimane and clerodane diterpenoids from Croton cnidophyllus

Three new halimane furanoditerpenoids(1-3)and three new clerodane furanoditerpenoids(4-6),along with seven known terpenoids including four pimarane diterpenoids(7-10)and three norisoprenoids(11-13)were isolated from the 95%EtOH extracts of the plants of Croton cnidophyllus.The 2D structures including absolute configuration of new furanoditerpenoids(1-6)were elucidated by analysis of their HRMS and NMR data as well as comparison of experi-mental and calculated ECD curves.Bioassay revealed that two compounds(8 and 9)possessed certain inhibitory effects against NO production stimulated by LPS,with IC_(50) values of 19.00±1.76 and 21.61±1.11μM,respectively.

基于Bagging指数平滑方法的航空客运需求预测

针对航空客运需求预测问题,提出了将Bagging集成算法与指数平滑方法相结合的Bagging指数平滑方法。首先,将航空需求时间序列数据分解为季节项、趋势项和噪音项;然后,通过移动平均采样方法对残差进行重采样,并将重采样的噪音新样本与季节项和趋势项重新相加,得到模型的训练样本;最后,利用Bagging指数平滑方法对每个时间序列训练样本进行预测分析,聚合得到最终预测结果。模型评估结果表明,该方法优于其他传统的时间序列预测方法。

离合器液压操纵系统效率试验与分析（英文）

分析了离合器液压操纵系统结构特点,提出一种离合器液压操纵系统传动效率计算方法。基于离合器液压操纵特性试验台,制定了离合器操纵系统动态传动效率试验方案。分别从踩/松离合踏板两个过程,对某型离合器液压操纵系统在定转速-变踏板速度和定踏板速度-变转速两种试验工况的力和行程传动效率进行了试验研究。试验结果表明离合器液压操纵系统传动效率计算方法具有较好的重复性,并且在踩踏板过程中随着踏板速度增加,离合器操纵系统力和行程传动效率增大;而在松踏板过程中随着踏板速度增加,离合器操纵系统力传动效率减小,行程传动效率增大;转速低于2 000 r/min时,转速变化对离合器操纵系统力和行程传动效率影响较小。

慢性阻塞性肺疾病合并呼吸衰竭患者行外周血TREM-1检测对序贯治疗切换点应用研究

目的:考察慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)合并呼吸衰竭患者行外周血髓样细胞触发受体-1(triggering receptor expressed on myeloid cells-1,TREM-1)检测对序贯治疗切换点应用研究。方法:收集120例COPD合并呼吸衰竭患者,随机分为对照组和观察组各60例。对照组接受2 h自主呼吸试验(spontaneous breathing trial,SBT)为无创序贯通气(non invasive positive pressure ventilation,NIPPV)选择时机,观察组接受外周血TREM-1≤90.0 pg/mL为NIPPV选择时机,检测两组患者机械通气治疗24 h后的应激激素、临床肺部感染评分和生命体征,记录两组的治疗时间和不良反应等。结果:两组的肾素(rennin,REN)、肾上腺素(Adrenaline,A)、去甲肾上腺素(noradrenaline,NA)和血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)比较,差异无统计学意义(P>0.05);与对照组比,观察组的临床肺部感染评分明显降低(P<0.05),两组患者的心率(heart rate,HR)、呼吸频率(respiratory rate,RR)、pH、动脉二氧化碳分压(arterial carbon dioxide partial pressure,PaCO 2)和动脉氧分压(partialpressureofoxygen,PaO 2)比较,差异无统计学意义(P>0.05),两组重症监护室(intensive care nursing,ICU)监护时间比较,差异无统计学意义(P>0.05);与对照组比,观察组有创通气时间、总机械通气时间和住院时间均明显降低(P<0.05),两组死亡、呼吸机相关性肺炎及再次插管发生比较,差异无统计学意义(P>0.05)。结论:COPD合并呼吸衰竭患者有创-无创序贯通气治疗期间以TREM-1作为切换点,有利于缩短患者创通气时间、总机械通气时间和住院时间。

不确定条件下机场群系统均衡配流模型研究

为探索客流在机场群的分布规律,以整个航空出行链为视角,综合考虑空中交通、地面交通和旅客出行选择偏好,构建机场群系统均衡配流模型.以路径时间、机场停留时间、出行票价和旅客类型为主要参考属性,提出机场群系统旅客出行成本模型.由于路径时间与流量相关且存在不确定性,基于预算超出时间对路径时间的均值与方差进行统一度量.综合路径时间、出行票价、机场停留时间与旅客类型,基于Logit模型建立旅客对航空出行路径的选择模型,将机场群系统的客流均衡条件转换为变分不等式.基于投影收缩算法对变分不等式求解,从而得出客流在机场群间的均衡分布状态.算例结果表明,机场群系统均衡配流模型有效建立了客流分布状态,调整路径时间、机场服务水平、票价等因素均可促进客流在机场群间的均衡分布.

Construction of NH2-MIL-125(Ti)/Bi2WO6 composites with accelerated charge separation for degradation of organic contaminants under visible light irradiation

Photocatalysis is considered as an ideal strategy for water pollution treatment.However,it remains challenging to design a highly efficient photo-catalytic system through regulating the charge flow via a precise approach.In this work,a novel NH2-MIL-125(Ti)/Bi2WO6 composite was constructed via self-assembly growing Bi2WO6 nanosheets on NH2-MIL-125(Ti)material.The characterization results demonstrated that NH2-MIL-125(Ti)was successfully incorporated into Bi2WO6 and the photoexcited carriers could be efficiently separated and transferred between the two components.NH2-MIL-125(Ti)/Bi2WO6 composites displayed enhanced photocatalytic activity for the removal of rhodamine B(RhB)and tetracycline(TC)under visible light irradiation,and the optimal weight ratio of NH2-MIL-125(Ti)was determined to be 7 wt%.The introduction of NH2-MIL-125(Ti)into Bi2WO6 could raise the absorption of visible light,accelerate the separation and transfer of charge carriers,and boost photocatalytic activity.This research presents a wide range of possibilities for the further development of novel composites in the field of environment purification.

Mulberry Diels-Alder-type adducts:isolation,structure,bioactivity,and synthesis

Mulberry Diels-Alder-type adducts(MDAAs)are unique phenolic natural products biosynthetically derived from the intermolecular[4+2]-cycloaddition of dienophiles(mainly chalcones)and dehydroprenylphenol dienes,which are exclusively distributed in moraceous plants.A total of 166 MDAAs with diverse skeletons have been isolated and identified since 1980.Structurally,the classic MDAAs characterized by the chalcone-skeleton dienophiles can be divided into eight groups(Types A−H),while others with non-chalcone dienophiles or some variations of classic MDAAs are non-classic MDAAs(Type I).These compounds have attracted significant attention of natural products and synthetic chemists due to their complex architectures,remarkable biological activities,and synthetic challenges.The present review provides a comprehensive summary of the structural properties,bioactivities,and syntheses of MDAAs.Cited references were collected between 1980 and 2021 from the SciFinder,Web of Science,and China National Knowledge Internet(CNKI).

Spectrofluorometric Assays of Human Collagenase Activity Using Native Collagen and Acetyl-Peptide Substrates

A selective, sensitive, and convenient assay for human collagenase is required because of its implication in diseases such as rheumatoid arthritis, osteoarthritis, and tumors. Here, a novel assay for human collagenase activity is described in which enzymatic degradation of native collagen or acetyl peptide is determined by using a fluorogenic reaction for oligopeptides. The oligopeptides are quantified spectrofluorometrically with either 3,4-dihydroxyphenylacetic acid or 1,2-dihydroxybenzen reaction in the presence of sodium periodate and sodium borate (pH 7 - 8). These reactions can selectively convert N-terminal Gly-containing oligopeptides and N-terminal Ile-containing oligopeptides to fluorescence (FL) compounds, respectively, but not proteins, acetyl peptides or amino acids. Under optimized conditions using 1.65 μM collagen IV or 1.5 mM Ac-GPQGI- AGQ as substrates, this assay exhibits a proportional relationship between FL intensities and human collagenase-3 (MMP-13) concentrations. It can assay endogenous collagenase activities in several biological samples, such as cultured human cells and cheek tissue.

考虑旅客出行延误的机场群航空客流均衡分配模型

针对不确定环境下的机场群航空客流分配问题,考虑旅客在全出行链上的出行延误,综合评估旅客的出行成本并建立出行效用函数,根据随机用户均衡原理构建了机场群航空客流均衡分配模型,最后设计基于变分不等式的投影收缩算法对模型进行求解.将模型应用到有长短途航线的机场群出行交通网络中,实例验证了所提出模型和算法的有效性.算例结果表明:调整地面交通水平、机场服务效率、航班飞行时间可靠性等措施可以降低旅客延误成本,促进客流在机场群中均衡分布.

In-situ embedded ultrafine Bi_(12)O_(17)Br_(2)nanotubes in MOF-derived hierarchical porous carbon for enhanced photocatalytic CO_(2)conversion to CO

Increasing the utilization efficiency of photogenerated electrons is highly recognized as one of the ef-ficient approaches to boost the photocatalytic CO_(2)conversion efficiency.Herein,ZIF-67-derived porous carbon(PC)material was employed for the construction of PC@ultrafine Bi_(12)O_(17)Br_(2)nanotubes(PC@BOB NTs)composites through a facile solvothermal synthesis in order to optimize the use of excited elec-trons in the BOB NTs.Photoelectrochemical characterization results revealed that the introduction of PC material achieved a faster charge separation rate in the PC@BOB composites,ensuring more photogener-ated electrons participate in the CO_(2)adsorption and activation process.Moreover,the pore structures of ZIF-67-derived PC material provided abundant confined spaces for the enrichment of CO_(2)molecules.Af-ter 5 h of Xenon lamp irradiation,PC@BOB composites exhibited obviously increased photocatalytic CO_(2)reduction activity in the pure water.When the addition amount of PC was 5 wt%,the PC@BOB-2 com-posite showed the highest CO evolution rate of 359.70μmol/g,which was 2.95 times higher than that of the pure BOB NTs.This work provides some independent insights into the applications of Metal-Organic Framework(MOF)-derived hierarchical porous structures to strengthen the CO_(2)enrichment,as well as the excited charge utilization efficiency,thus achieving a high solar-to-fuel conversion efficiency.

(+)/(-)-Mycosphatide A,a pair of highly oxidized polyketides with lipid-lowering activity from the mangrove endophytic fungus Mycosphaerella sp.SYSU-DZG01

(±)-Mycosphatide A(1a/1b),a pair of highly oxidized enantiomeric polyketides featuring a unique5/5/6/5-fused tetracyclic ring system,were isolated from the mangrove endophytic fungus Mycosphaerella sp.SYSU-DZG01.Their structures were established by extensive spectroscopic analyses,single crystal Xray diffraction,and experimental electronic circular dichroism(ECD)spectra comparison.The plausible biosynthetic pathway of 1 was proposed,which involved the generation of a key spiro[4.5]decane scaffold.Compounds(+)-1a and(-)-1b exhibited significant lipid-lowering activity in 3T3-L1 adipocytes model,with EC50values of 7.85±1.56 and 8.87±0.80μmol/L,respectively.

Long-term functional maintenance of primary hepatocytes in vitro using macroporous hydrogels engineered through liquid-liquid phase separation

Preserving the functionality of hepatocytes in vitro poses a significant challenge in liver tissue engineering and bioartificial liver,as these cells rapidly lose their metabolic and functional characteristics after isolation.Inspired by the macroporous structures found in native liver tissues,here we develop synthetic hydrogel scaffolds that closely mimic the liver’s structural organization through the phase separation between polyethylene glycol(PEG)and polysaccharides.Our hydrogels exhibit interconnected macroporous structures and appropriate mechanical properties,providing an optimal microenvironment conducive to hepatocyte adhesion and the formation of sizable aggregates.Compared to two-dimensional hepatocyte cultures,enhanced functionalities of hepatocytes cultured in our macroporous hydrogels were observed for 14 days,as evidenced by quantitative reverse-transcription–polymerase chain reactions(qRT-PCR),immunofluorescence,and enzyme linked immunosorbent assay(ELISA)analyses.Protein sequencing data further confirmed the establishment of cell–cell interactions among hepatocytes when cultured in our hydrogels.Notably,these hepatocytes maintained a protein expression lineage that closely resembled freshly isolated hepatocytes,particularly in the Notch and tumor necrosis factor(TNF)signaling pathways.These results suggest that the macroporous hydrogels are attractive scaffolds for liver tissue engineering.

Discovery of a highly potent and orally available importin-β1 inhibitor that overcomes enzalutamide-resistance in advanced prostate cancer

Nuclear transporter importin-β1 is emerging as an attractive target by virtue of its prevalence in many cancers.However,the lack of druggable inhibitors restricts its therapeutic proof of concept.In the present work,we optimized a natural importin-β1 inhibitor DD1 to afford an improved analog DD1-Br with better tolerability(>25 folds)and oral bioavailability.DD1-Br inhibited the survival of castration-resistant prostate cancer(CRPC)cells with sub-nanomolar potency and completely prevented tumor growth in resistant CRPC models both in monotherapy(0.5 mg/kg)and in enzalutamidecombination therapy.Mechanistic study revealed that by targeting importin-β1,DD1-Br markedly inhibited the nuclear accumulation of multiple CRPC drivers,particularly AR-V7,a main contributor to enzalutamide resistance,leading to the integral suppression of downstream oncogenic signaling.This study provides a promising lead for CRPC and demonstrates the potential of overcoming drug resistance in advanced CRPC via targeting importin-β1.

自由群von Neumann代数的L^(p)分解

本文研究基于n阶自由群Fn的非交换L^(p)空间,对于n=2和n=∞,给出所对应非交换L^(p)空间互相同构的一个新证明,并给出该同构的具体形式.进一步讨论自由群von Neumann代数的L^(p)分解与von Neumann代数刚性问题的联系.

NAC对特发性肺纤维化患者血清结缔组织生长因子和纤维连接蛋白水平的影响

目的:探讨N-乙酰半胱氨酸(N-acety-L-cysteine,NAC)对特发性肺纤维化(idiopathic pulmonary fibrosis,IPF)患者血清结缔组织生长因子(connective tissue growth factor,CTGF)和纤维连接蛋白(fibronectin,FN)水平的影响。方法:收集2016年1月至2018年12月,在昆山市第一人民医院收治且确诊为IPF患者150例,随机分为对照组和研究组,每组各75例。所有患者均接受常规治疗,研究组在上述基础上口服NAC。两组连续治疗6个月。记录并比较两组患者治疗前后的布罗格(Brog)呼吸困难评分、肺通气功能[肺活量占预计值百分比(prediced vital capacity,VC%pred)、用力肺活量占预计值百分比(prediced forced vital capacity,FVC%pred)]、血氧分压值(partial pressure of oxygen,PaO 2)、一氧化碳弥散量值(diffusion capacity for carbon monoxide of the lung,DLco),血清CTGF和FN的表达水平及NAC的治疗效果。结果:治疗前,对照组和研究组的Brog呼吸困难评分、VC%pred、FVC%pred、PaO 2、Dlco、血清CTGF和FN表达水平差异无统计学意义(P>0.05)。治疗后,对照组和研究组的Brog呼吸困难评分较治疗前明显降低,差异具有统计学意义(t值分别为3.192和5.385,P值均<0.05);对照组和研究组的VC%pred和FVC%pred较治疗前明显增高,差异具有统计学意义(t值分别为1.732和2.041,P值均<0.05);对照组和研究组CTGF和FN表达水平较治疗前明显降低,差异具有统计学意义(t值分别为1.732,2.041,1.070和12.652,P值均<0.05);对照组和研究组的PaO 2和DLco较治疗前明显增高,差异具有统计学意义(t值分别为4.373,8.297,2.864和5.062,P值均<0.05)。与对照组相比,治疗后观察组的Brog呼吸困难评分、CTGF和FN明显降低(t值分别为2.128、5.196和45.445,P值均<0.05),VC%pred、FVC%pred、PaO 2和DLco明显增高(t值分别为3.241、3.625、3.337和2.280,P值均<0.05),差异均具有统计学意义。与对照组比,观察组的总有效率较高(χ^2=4.160,P<0.05)。两组均未发生明显的不良反应。结论:IPF患者外周血CTGF与FN显著增高,给予NAC治疗,可显著降低外周血CTGF与FN表达水平,提示NAC可能有降低外周血CTGF与FN的作用,但具体机理仍需深入研究。

Multifunctional polymeric micelle-based chemo-immunotherapy with immune checkpoint blockade for efficient treatment of orthotopic and metastatic breast cancer

Immunotherapy has become a highly promising paradigm for cancer treatment. Herein, a chemo-immunotherapy was developed by encapsulating chemotherapeutic drug doxorubicin(DOX) and Toll-like receptor 7 agonist imiquimod(IMQ) in low molecular weight heparin(LMWH)-D-α-tocopheryl succinate(TOS) micelles(LT). In this process, LMWH and TOS were conjugated by ester bond and they were not only served as the hydrophilic and hydrophobic segments of the carrier, but also exhibited strong anti-metastasis effect. The direct killing of tumor cells mediated by DOX-loaded micelles(LT-DOX)generated tumor-associated antigens, initiating tumor-specific immune responses in combination with IMQ-loaded micelles(LT-IMQ). Furthermore, the blockade of immune checkpoint with programmed cell death ligand 1(PD-L1) antibody further elevated the immune responses by up-regulating the maturation of DCs as well as the ratios of CD8+ CTLs/Treg and CD4+ Teff/Treg. Therefore, such a multifunctional strategy exhibited great potential for inhibiting the growth of orthotopic and metastatic breast cancer.

Ab initio modeling of the energy landscape for screw dislocations in body-centered cubic high-entropy alloys

In traditional body-centered cubic(bcc)metals,the core properties of screw dislocations play a critical role in plastic deformation at low temperatures.Recently,much attention has been focused on refractory high-entropy alloys(RHEAs),which also possess bcc crystal structures.However,unlike face-centered cubic high-entropy alloys(HEAs),there have been far fewer investigations into bcc HEAs,specifically on the possible effects of chemical short-range order(SRO)in these multiple principal element alloys on dislocation mobility.Here,using density functional theory,we investigate the distribution of dislocation core properties in MoNbTaW RHEAs alloys,and how they are influenced by SRO.The average values of the core energies in the RHEA are found to be larger than those in the corresponding pure constituent bcc metals,and are relatively insensitive to the degree of SRO.However,the presence of SRO is shown to have a large effect on narrowing the distribution of dislocation core energies and decreasing the spatial heterogeneity of dislocation core energies in the RHEA.It is argued that the consequences of the mechanical behavior of HEAs is a change in the energy landscape of the dislocations,which would likely heterogeneously inhibit their motion.

Simulation study on the active layer thickness and the interface of a-IGZO-TFT with double active layers

In this paper, ATLAS 2D device simulator of SILVACO was used for device simulation of inverted- staggered thin film transistor using amorphous indium gallium zinc oxide as active layer （a-IGZO-TFT） with double active layers, based on the density of states （DOS） model of amorphous material. The change of device performance induced by the thickness variation of each active layer was studied, and the interface between double active layers was analyzed. The best performance was found when the interface was near the edge of the channel, by optimizing the thickness of each active layers, the high performance device of threshold voltage （Vth） = -0.89 V, sub-threshold swing （SS）= 0.27, on/off current ratio （IoN/IoFF） = 6.98 × 10^14 was obtained.

Enhanced photocatalytic performance of carbon quantum dots/Bi OBr composite and mechanism investigation

Novel carbon quantum dots（CQDs）/Bi OBr composite photocatalysts have been constructed through a facile hydrothermal synthesis in the presence of ionic liquid 1-hexadecyl-3-methylimidazolium bromide（[C16 mim]Br）. Series of characterizations have been performed to confirm the uniform distribution of CQDs in Bi OBr nanosheets and the synergistic effect for photocatalytic degradation organic pollutants between CQDs and Bi OBr. The results show that 3.1 wt% CQDs/Bi OBr photocatalyst possesses the best photocatalytic activity for the degradation of colorless antibiotic tetracycline（TC）, endocrine disrupter bisphenol A（BPA） and dye rhodamine B（Rh B）, under visible light irradiation, which exhibited the highest photocatalytic performance. The enhanced photocatalytic performance for CQDs/Bi OBr composites could be attributed to the wider optical absorption range and fast separation of photogenerated charge carriers after the introduction of CQDs. The key roles of CQDs for the enhanced photocatalytic activity of Bi OBr have been discussed. A possible mechanism of CQDs/Bi OBr on the enhancement of visible light performance was proposed.

Structural, optical and electrical properties of ZnO： B thin films with different thickness for bifacial a-Si：H/c-Si heterojunction solar cells

Textured surface boron-doped zinc oxide （BZO） thin films were fabricated by metal organic chemical vapor deposition as transparent conductive oxide （TCO） for solar cells. The surface microstructure was characterized by X-ray diffraction spectrum and scan- ning electron microscope. The optical transmittance was shown by optical transmittance microscope and the electrical properties were tested by Hall measurements. The thickness of the BZO film has crucial impact on the surface morphology, optical transmittance, and resistivity. The electrical and optical properties as well as surface microstructure varied inconsistently with the increase of the film thickness. The grain size and the surface roughness increased with the increase of the film thickness. The conductivity increased from 0.96x 103 tO 6.94x 103 S/cm while the optical transmittance decreased from above 85% to nearly 80% with the increase of film thickness from 195 to 1021 nm. The BZO films deposited as both front and back transparent electrodes were applied to the bifacial p- type a-Si：H/i-type a-Si：H/n-type c-Si/i-type a-Si：H/n＋-type a-Si：H heterojunction solar cells to obtain the optimized parameter of thickness. The highest efficiency of all the samples was 17.8% obtained with the BZO film thickness of 829 nm. Meanwhile, the fill factor was 0.676, the open- circuit voltage was 0.63 Vand the short-circuit density was 41.79 mA/cm2. The properties of the solar cells changing with the thickness were also investigated.