A simple and efficient method for potential point-of-care diagnosis of human papillomavirus genotypes: combination of isothermal recombinase polymerase amplification with lateral flow dipstick and reverse dot blot

Cervical cancer is the second most common cancer in the world’s woman population with a high incidence in developing countries where diagnostic conditions for the cancer are poor. The main culprit causing the cancer is the human papillomavirus (HPV). HPV is divided into three major groups, i.e., high-risk (HR) group, probable high-risk (pHR) group, and low-risk (LR) group according to their potential of causing cervical cancer. Therefore, developing a sensitive, reliable, and cost-effective point-of-care diagnostic method for the virus genotypes in developing countries even worldwide is of high importance for the cancer prevention and control strategies. Here we present a combined method of isothermal recombinase polymerase amplification (RPA), lateral flow dipstick (LFD), and reverse dot blot (RDB), in quick point-of-care identification of HPV genotypes. The combined method is highly specific to HPV when the conserved L1 genes are used as targeted genes for amplification. The method can be used in identification of HPV genotypes at point-of-care within 1 h with a sensitivity of low to 100 fg of the virus genomic DNA. We have demonstrated that it is an excellent diagnostic point-of-care assay in monitoring the disease without time-consuming and expensive procedures and devices.

     

一种表面裂纹高温断裂韧性测试方法

提出了一种表面裂纹高温断裂韧性测试方法，包括试样加热、温控和裂纹嘴张开位移测试方法．该方法适合于在相对简单的条件下测试表面裂纹高温断裂韧性．最后给出了铝合金焊缝表面裂纹高温断裂韧性的测试结果．     

含内埋裂纹的板条瞬态响应分析

利用线弹簧模型求解了阶跃载荷作用下含内埋裂纹的无限长板条问题,对采用基于线弹簧模型的解析方法求解三维裂纹动态问题作了有益的探索。定性解释了动态线弹簧采用静态线弹簧本构关系的可行性,通过积分变换方法,导出了描述内埋裂纹板条动态问题的Cauchy型奇异积分方程。进行了数值计算,对模型应用的合理性作了理论解释,并对内埋裂纹板条瞬态响应的影响因素作了细致的分析。     

Using mixed integer programming models to synchronously determine production levels and market prices in an integrated market for roundwood and forest biomass

Annals of Operations Research - We study a problem of integrating the supply chain of roundwood with the supply chain of forest biomass. The developed optimization model is a multiperiod,...     

Oscillatory stability of quantum droplets in $\text{}{ \mathcal P }{ \mathcal T }$-symmetric optical lattice

We study stability and collisions of quantum droplets (QDs) forming in a binary bosonic condensate trapped in parity-time (${ \mathcal P }{ \mathcal T }$)-symmetric optical lattices. It is found that the stability of QDs in the ${ \mathcal P }{ \mathcal T }$-symmetric system depends strongly on the values of the imaginary part W₀ of the ${ \mathcal P }{ \mathcal T }$-symmetric optical lattices, self-repulsion strength g, and the condensate norm N. As expected, the ${ \mathcal P }{ \mathcal T }$-symmetric QDs are entirely unstable in the broken ${ \mathcal P }{ \mathcal T }$-symmetric phase. However, the ${ \mathcal P }{ \mathcal T }$-symmetric QDs exhibit oscillatory stability with the increase of N and g in the unbroken ${ \mathcal P }{ \mathcal T }$-symmetric phase. Finally, collisions between ${ \mathcal P }{ \mathcal T }$-symmetric QDs are considered. The collisions of droplets with unequal norms are completely different from that in free space. Besides, a stable ${ \mathcal P }{ \mathcal T }$-symmetric QDs collides with an unstable ones tend to merge into breathers after the collision.     

Optimization of Extraction or Purification Process of Multiple Components from Natural Products: Entropy Weight Method Combined with Plackett–Burman Design and Central Composite Design

In this paper, the optimization of the extraction/purification process of multiple components was performed by the entropy weight method (EWM) combined with Plackett–Burman design (PBD) and central composite design (CCD). We took the macroporous resin purification of Astragalus saponins as an example to discuss the practicability of this method. Firstly, the weight of each component was given by EWM and the sum of the product between the componential content and its weight was defined as the comprehensive score, which was taken as the evaluation index. Then, the single factor method was adopted for determining the value range of each factor. PBD was applied for screening the significant factors. Important variables were further optimized by CCD to determine the optimal process parameters. After the combination of EWM, PBD and CCD, the resulting optimal purification conditions were as follows: pH value of 6.0, the extraction solvent concentration of 0.15 g/mL, and the ethanol volume fraction of 75%. Under the optimal conditions, the practical comprehensive score of recoveries of saponins was close to the predicted value (n = 3). Therefore, the present study provided a convenient and efficient method for extraction and purification optimization technology of multiple components from natural products.     

密度泛函理论研究LiX(X=H,D,T)体系的热力学性质

运用量子力学从头计算方法,计算了氢化锂(氘化锂、氚化锂)分子的部分热力学函数和力学、光谱学性质。基于准简谐Debye模型,计算了固体Li的振动内能、振动和电子熵,探讨了Li吸收氢同位素气体生成一氢化物的反应熵变、生成焓变和生成Gibbs自由能及氢同位素的平衡离解压。结果显示:在Li吸收同位素气体生成一氢化物的反应中,生成焓变和反应熵变均为负值,且随温度升高,绝对值越大,Gibbs自由能则向正的方向增加。热力学上,在相同温度和压力下,氢置换一氢化物中的氘和氚、及氘置换氚的反应更易发生。     

预期理论权重函数π的由来、质疑及Tversky的阐释

借助权重函数π的导出,Kahneman和Tversky解释了一些期望效用理论无法预测和描述的抉择(如艾勒悖论),使预期理论成为风险条件下行为决策的重要描述性模型.文章回顾了推导权重函数的基本假设及权重函数各特性的推导过程,介绍沿用相同的推导逻辑提出的对该函数特性的质疑,及Tversky对质疑的回应和解释.冀透过对权重函数的审视,将质疑的焦点转向最大化原则本身.     

衬底温度对PLD制备的Mo薄膜结构及表面形貌的影响

 运用脉冲激光沉积(PLD)技术在Si(100)基片上沉积了金属Mo薄膜。在激光重复频率2 Hz,能量密度5.2 J/cm²,本底真空10^－6 Pa的条件下,研究Mo薄膜的结构和表面形貌,讨论了衬底温度对薄膜形貌与结构的影响。原子力显微镜(AFM)图像和X射线小角衍射(XRD)分析表明,薄膜表面平整、光滑,均方根粗糙度小于2 nm。沉积温度对Mo薄膜结构和表面形貌影响较大,在373~573 K范围内随着温度升高,薄膜粗糙度变小,结晶程度变好。     

Divisibility among power GCD matrices and among power LCM matrices on three coprime divisor chains

Let h be a positive integer and S?=?{x ₁,?…?,?x _h } be a set of h distinct positive integers. We say that the set S is a divisor chain if x _σ(1) ∣?…?∣ x _σ(h) for a permutation σ of {1,?…?,?h}. If the set S can be partitioned as S?=?S ₁?∪?S ₂?∪?S ₃, where S ₁, S ₂ and S ₃ are divisor chains and each element of S _i is coprime to each element of S _j for all 1?≤?i?<?j?≤?3, then we say that the set S consists of three coprime divisor chains. The matrix having the ath power (x _i , x _j ) ^a of the greatest common divisor of x _i and x _j as its i, j-entry is called the ath power greatest common divison (GCD) matrix on S, denoted by (S ^?a ). The ath power least common multiple (LCM) matrix [S ^?a ] can be defined similarly. In this article, let a and b be positive integers and let S consist of three coprime divisor chains with 1?∈?S. We show that if a?∣?b, then the ath power GCD matrix (S ^?a ) (resp., the ath power LCM matrix [S ^?a ]) divides the bth power GCD matrix (S ^?b ) (resp., the bth power LCM matrix [S ^?b ]) in the ring M _h (Z) of h?×?h matrices over integers. We also show that the ath power GCD matrix (S ^?a ) divides the bth power LCM matrix [S ^?b ] in the ring M _h (Z) if a?∣?b. However, if a???b, then such factorizations are not true. Our results extend Hong's and Tan's theorems and also provide further evidences to the conjectures of Hong raised in 2008.