Novel indole and quinoline alkaloids from Melodinus yunnanensis

6/7-Seco rearranged spiro-indolone alkaloids,meloyunines A(1)and B(2)and a monoterpenoid quinoline alkaloid meloyunine C(3)together with its possible intermediate 14,15-dehydromelohenine B(4),and their precursorΔ14-vincamenine(5)were isolated from Melodinus yunnanensis.All structures were elucidated based on NMR,FTIR,UV,and MS spectroscopic data.The isolation of monoterpenoid indole,quinoline,and its immediate from the same plant chemically supported the biosynthesis of quinoline from indole.Compound 2 was cytotoxic against several human cancer cell lines.

Coupling Among CH Stretching, Bending and Rocking Vibrational Modes in CH2Cl2

Infrared absorption spectra of gaseous CH2Cl2 in the regions of 1200-12000 cm^-1 were measured using a Bruker IFS 120HR Fourier transform spectrometer in conjunction with a nmltipass cell. 47 vibrational levels of overtone and combinational spectral lines of the CH stretching （v1, v6）, bending （v2）, and rocking （v8） modes were analyzed and assigned. Utilizing the normal mode model and considering the coupling among CH stretching, bending and rocking vibrations, values of the harmonic frequency wi, the anharmonic constant xij, and the coefficients of Fermi and the Darling-Dennison resonances of v1, v6, v2 and v8 modes were also determined from experimental spectral data with nonlinear least-square fitting. These spectral constants reproduced the experimental levels very well. These results showed that Fermi resonance between CH stretching and rocking vibrations （kiss=-254.63 cm^-1） is stronger than that between CH stretching and bending vibrations （k122 = 54.87 cm^-1 ）; and that Darling-Dennison resonances between CH stretching and bending vibrations （k166=-215.28 cm^-1） is also much stronger than that between CH bending and rocking vibrations （k2288=5.72 cm^-1）.

同步永磁耦合器动力学特性仿真研究（英文）

针对同步筒式永磁耦合器,通过仿真软件计算了其主动永磁转子与从动永磁转子之间的转角差与所传递转矩的关系曲线。在扭矩曲线工作点附近,采用线性化处理,定义了永磁耦合器的等效扭转刚度K。采用合理的假设与简化,建立了同步永磁耦合器在工作过程中的动力学微分方程,然后进行拉普拉斯变换获得系统传递函数。永磁耦合器在工作过程中会经常遇到冲击性负载或正弦波负载,分别采用单位脉冲信号与正弦波信号进行模拟,求解系统的时间响应曲线,验证同步永磁耦合器的抗冲击性与减振性。研究结果表明:永磁耦合器在工作过程中遇到冲击性负载时,转角差增量会随着系统固有频率不断衰减振荡直至消除;当遇到周期性正弦波负载时,转角差增量的瞬态响应会随着系统固有频率不断衰减振荡直至消除,转角差增量的稳态响应表现为伴随着激振源持续振荡,但相位角滞后于激振源,稳态响应频率与强迫振动的频率相同,稳态响应振幅与永磁耦合器扭转刚度有关,最终验证了同步永磁耦合器具有优良的抗冲击性与减振性。

Effects of the long wavelength-filtered continuousspectrum on natural refractive development in juvenile guinea pigs

AIM: To investigate the effects of spectral composition and light intensity on natural refractive development in guinea pigs.METHODS: A total of 124 pigmented guinea pigs(2-week-old) were randomly assigned to three groups at high(Hi;4000 lx), medium(Me;400 lx) and low(Lo;50 lx) light intensities under a 12:12 light/dark cycle for 6 wk. Each group was subdivided into subgroups with the following spectra: broad spectrum Solux halogen light(BS), 600 nm above-filtered continuous spectrum(600F), 530 nm above-filtered continuous spectrum(530F), and 480 nm above-filtered continuous spectrum(480F;HiBS: n=10, Hi600F: n=10, Hi530F: n=10, Hi480F: n=10, MeBS: n=10, Me600F: n=10, Me530F: n=10, Me480F: n=10, LoBS: n=11, Lo600F: n=12, Lo530F: n=10, Lo480F: n=11). Refractive error, corneal curvature radius, and axial dimensions were determined by cycloplegic retinoscopy, photokeratometry, and A-scan ultrasonography before and after 2, 4, and 6 wk of treatment. Average changes from both eyes in the ocular parameters and refractive error were compared among different subgroups.RESULTS: After 6 wk of exposure, high-intensity lighting enhanced hyperopic shift;medium-and low-intensity lighting enhanced myopic shift(P<0.05). Under the same spectrum, axial increase was larger in the low light intensity group than in the medium and high light intensity groups(HiBS: 0.65±0.02 mm, MeBS: 0.67±0.01 mm, LoBS:0.82±0.02 mm;Hi600 F: 0.64±0.02 mm, Me600F: 0.67±0.01 mm, Lo600F: 0.81±0.01 mm;Hi530F: 0.64±0.02 mm, Me530F: 0.67±0.01 mm, Lo530F: 0.73±0.02 mm;Hi480F: 0.64±0.01 mm, Me480F: 0.66±0.01 mm, Lo480F: 0.72±0.02 mm;P<0.05). Under 400 lx, there was a faster axial increase in the MeBS group than in the Me480F group(P<0.05). Under 50 lx, axial length changes were significantly larger in LoBS and Lo600F than in Lo530F and Lo480F(P<0.01).CONCLUSION: Under high-intensity lighting, high light intensity rather than spectrum distributions that inhibits axial increase. Under medium-and low-intensity lighting, filtering out the long wavelength inhibits axial growth in juvenile guinea pigs.

Impact of type 2 diabetes on adenoma detection in screening colonoscopies performed in disparate populations

BACKGROUND The Black/African Ancestry(AA)population has a higher prevalence of type 2 diabetes mellitus(T2DM)and a higher incidence and mortality rate for colorectal cancer(CRC)than all other races in the United States.T2DM has been shown to increase adenoma risk in predominantly white/European ancestry(EA)populations,but the effect of T2DM on adenoma risk in Black/AA individuals is less clear.We hypothesize that T2DM has a significant effect on adenoma risk in a predominantly Black/AA population.AIM To investigate the effect of T2DM and race on the adenoma detection rate(ADR)in screening colonoscopies in two disparate populations.METHODS A retrospective cohort study was conducted on ADR during index screening colonoscopies(age 45-75)performed at an urban public hospital serving a predominantly Black/AA population(92%)(2017-2018,n=1606).Clinical metadata collected included basic demographics,insurance,body mass index(BMI),family history of CRC,smoking,diabetes diagnosis,and aspirin use.This dataset was combined with a recently reported parallel retrospective cohort data set collected at a suburban university hospital serving a predominantly White/EA population(87%)(2012-2015,n=2882).RESULTS The ADR was higher in T2DM patients than in patients without T2DM or prediabetes(35.2%vs 27.9%,P=0.0166,n=981)at the urban public hospital.Multivariable analysis of the combined datasets showed that T2DM[odds ratio(OR)=1.29,95%confidence interval(CI):1.08-1.55,P=0.0049],smoking(current vs never OR=1.47,95%CI:1.18-1.82,current vs past OR=1.32,95%CI:1.02-1.70,P=0.0026),older age(OR=1.05 per year,95%CI:1.04-1.06,P<0.0001),higher BMI(OR=1.02 per unit,95%CI:1.01-1.03,P=0.0003),and male sex(OR=1.87,95%CI:1.62-2.15,P<0.0001)were associated with increased ADR in the combined datasets,but race,aspirin use and insurance were not.CONCLUSION T2DM,but not race,is significantly associated with increased ADR on index screening colonoscopy while controlling for other factors.

基于响应值中心加权卷积特征的图像检索算法

提出一种新颖的基于交叉熵的损失,将该损失应用于经典的卷积神经网络上获得了更优的嵌入空间。设计了一种基于响应值中心加权的卷积特征聚合算法处理神经网络得到的三维卷积特征,该算法通过当前位置响应值以及高斯中心计算获得特征图的空间加权系数,减少了三维卷积特征图降成一维图像特征描述子时的信息丢失,并实现了目标区域的增强。最后,将得到的图像特征描述子用于检索任务。在CUB-200-2011数据集上通过消融实验分别验证了损失函数和响应值中心加权算法的有效性。本文算法在Paris6k、Oxford5k、CUB-200-2011、CARS196四个数据集上较当前已有的检索方法获得了更高的准确率和召回率。

CCT4 suppression inhibits tumor growth in hepatocellular carcinoma by interacting with Cdc20

Background:The chaperonin containing t-complex(CCT)proteins play an important role in cell cycle-related protein degradation in yeast and mammals.The role of the chaperonin containing t-complex 4(CCT4),one subtype of CCT proteins,in the progress of hepatocellular carcinoma(HCC)was not fully elucidated.Here,we aimed to explore the mechanisms of CCT4 in HCC.Methods:In this study,we used the UALCAN platform to analyze the relationship between CCT4 and HCC,and the association of CCT4 with the overall survival(OS)of HCC patients was also analyzed.CCT4 expression in HCC tumor tissues and normal tissues was also determined by western blot(WB)assay.Lentivirus vector was used to knock down the CCT4 expression,and quantitative polymerase chain reaction and WB were used to determine the level of CCT4 in HCC cell lines.Cell counting kit-8(CCK-8)and 5-ethynyl-20-deoxyuridine(EdU)assays were used to detect the cell proliferation,and flow cytometry(FCM)was performed to evaluate the effect of CCT4 on the apoptosis of HCC cells.Co-immunoprecipitation(co-IP)assay and WB were used to explore the mechanisms of CCT4 regulating the growth of HCC.Data were calculated from at least three replicate experiments and expressed as mean±standard deviation.Student’s t test,paired t test,and Kaplan–Meier analysis were used to compare across different groups.Results:We found CCT4 was upregulated in HCC tissues compared with normal tissues,and its high expression was associated with poor prognosis(P<0.001).CCT4 was significantly increased in HCC tumor tissues compared with normal tissues(0.98±0.12 vs.0.23±0.05,t=7.73,P<0.001).After being transfected with CCT4 short-hairpin RNA(shRNA),CCT4 was decreased in mRNA level and protein level in both Huh7(mRNA level:0.41±0.07 vs.1.01±0.11,t=8.09,P=0.001;protein level:0.61±0.03 vs.0.93±0.07,t=7.19,P=0.002)and Hep3b cells(mRNA level:0.55±0.11 vs.1.04±0.15,t=4.51,P=0.011;protein level:0.64±0.10 vs.0.95±0.08,t=4.32,P=0.012).CCK8 assay indicated that CCT4 knockdown inhibited cell proliferation in both Huh7(OD value of 3 days:0.60±0.14 vs.0.97±0.16,t=3.13,P=0.036;OD value of 4 days:1.03±0.07 vs.1.50±0.12,t=5.97,P=0.004)and Hep3b(OD value of 3 days:0.69±0.14 vs.1.10±0.11,t=3.91,P=0.017;OD value of 4 days:1.12±0.12 vs.1.48±0.13,t=3.55,P=0.024)cells.EdU assay showed that CCT4 knockdown inhibited the cell proliferation in both Huh7(EdU positive rate:[31.25±3.41]%vs.[58.72±3.78]%,t=9.34,P=0.001)and Hep3b cells(EdU positive rate:[44.13±7.02]%vs.[61.79±3.96]%,t=3.79,P=0.019).FCM assay suggested that CCT4 knockdown induced apoptosis in HCC cells(apoptosis rate of Huh7:[9.10±0.80]%vs.[3.66±0.64]%,t=-9.18,P=0.001;apoptosis rate of Hep3b:[6.69±0.72]%vs.[4.20±0.86]%,t=-3.84,P=0.018).We also found that CCT4 could regulate anaphase-promoting complex(APC)Cdc20 activity via interacting with Cdc20.Furthermore,CCT4 knockdown induced securin(0.65±0.06 vs.0.44±0.05,t=-4.69,P=0.009)and B-cell lymphoma-2(Bcl-2)interacting mediator of cell death(Bim;0.96±0.06 vs.0.61±0.09,t=securin inhibited cell growth by downregulating cyclin D1(0.65±0.05 vs.1.04-±5.65,0.07,Pt==0.005)accumulation.The upregulation of 8.12,P=0.001),and the accumulation of Bim inhibited Bcl-2(0.77±0.04 vs.0.87±0.04,t=3.00,P=0.040)and activated caspase 9(caspase 9:0.77±0.04 vs.0.84±0.05,t=1.81,P=0.145;cleaved caspase 9:0.64±0.06 vs.0.16±0.07,t=1.81,P=0.001),which led to elevated apoptosis.Conclusions:Overall,these results showed that CCT4 played an important role in HCC pathogenesis through,at least partly,interacting with Cdc20.

Identification of Newly Diagnosed Diabetes and Prediabetes Using Fasting Plasma Glucose and Urinary Glucose in a Chinese Population： A Multicenter Cross-Sectional Study

Background： Although fasting plasma glucose （FPG） has been highly recommended as the sole test for diabetes screening, the efficacy of FPG alone for diabetes screening is potentially limited due to its low sensitivity. The aim of this study was to improve the efficacy of FPG for diabetes screening using urinary glucose （UG）. Methods： This study was initiated on November 12, 2015, and ended on June 28, 2016. A representative sample of individuals aged between 18 and 65 years, with no history of diabetes, from 6 cities in Jiangsu Province participated in this study. A 75-g oral glucose tolerance test was used to diagnose diabetes. All urine samples were collected within 2 h of oral glucose loading to measure UG. Partial correlation analyses were used to evaluate the associations between UG and other glycemic variables, including FPG, 2-h plasma glucose （2h-PG）, and glycated hemoglobin A 1 c, after adjustment for age. Tile perfbnnance of UG was evaluated using a receiver operating characteristic （ROC） curve analysis. Results： Of the 7485 individuals included, 8% were newly diagnosed with diabetes and 48.7% had prediabetes. The areas under the ROC curves for UG were 0.75 for estimation of 2h-PG ≥7.8 mmol/L and 0,90 for 2h-PG ≥11.1 mmol/L, respectively. The sensitivity and specificity of UG were 52.3% and 87.8%, respectively, for 2h-PG ≥7.8 mmol/L （cutoff point ≥130 mg）, and 83.5% and 87.5%, respectively, for 2h-PG ≥11.1 mmol/L （cutoff point ≥ 178.5 mg）. The combination of FPG and UG demonstrated a significantly higher sensitivity than that of FPG alone for the identification of diabetes （[483/597] 80.9% vs. [335/597] 56.1%, x2 = 85.0, P 〈 0.001） and glucose abnormalities （[2643/4242] 62.3% vs. [2365/4242] 55.8%, x2 = 37.7 P 〈 0.001）. Conclusions： The combination of UG and FPG substantially improves the efficacy of using FPG alone for diabetes screening; this combination might be a practical screening tool and is worth being recommended in the future.