应用于量子含时波包方法的高精度透明边界条件

本文提出了一种适用于量子含时波包方法的透明边界条件. 该量子含时波包方法结合分离变量表象方法使用的时候,本质上是具有谱收敛性质的. 相对于以往的复数吸收势,该透明边界条件的突出优点是其对于波函数的能谱分布并不敏感. 采用具有共振态的一维势垒散射模型,本文对该方法的特点做了阐述.     

5-Endo-dig cyclizations in organic syntheses

Molecular Diversity - The favorability of ring closure reactions as per Baldwin rules has gained immense importance recently. This is evident from the current literature such as research articles,...     

Isolation,Structure Elucidation and Antimicrobial Evaluation of Natural Pentacyclic Triterpenoids and Phytochemical Investigation of Different Fractions of Ziziphus spina-christi (L.) Stem Bark Using LCHRMS Analysis

Ziziphus spina-christi L. (ZSC-L) is a tree with thorny branches, belongs to the family Rhamnaceae and grows in the sub-tropics. The purpose of this research is to isolate and partially purify bioactive components from the crude ethanol extract of the stem bark of ZSC-L. Besides, bioassay-guided fractionation of ZSC-L stem bark was conducted using different solvents. The solvents were reutilized to minimize the production cost and environmental harm. In addition, the antimicrobial activities of the fractions were analyzed, followed by metabolic profiling using LC-HRMS. The n-butanol fraction showed the highest antimicrobial efficacy, so it was subjected to further purification. For the first time, two major compounds were isolated from the stem bark of ZSC-L and identified as lupane-type pentacyclic triterpenoids betulinic acid and betulin. Both compounds were used as antibacterial and anticancer agents and considered as a green product as the extraction procedure reduced the use of hazardous chemicals. Metabolic characterization of ZSC-L and its bioactive fractions were performed using LC-HR-ESI-MS and the results revealed the dereplication of 36 compounds belonging to different chemical classes. Flavonoids and triterpenes were the most prominent metabolite classes in the different fractions. The molecular docking results were obtained by studying the interaction of betulin and betulinic acid with antimicrobial receptors (4UYM, 1IYL, 1AJ2, 6J7L, 1AD4, 2VEG) to support the in vitro results. Our study highlights that Ziziphus spina-christi and its phytoconstituents, especially triterpenoids, act as a promising antimicrobial candidate in pharmaceutical and clinical applications.     

Genesis and Mechanism of Some Cancer Types and an Overview on the Role of Diet and Nutrition in Cancer Prevention

Cancer is a major disease with a high mortality rate worldwide. In many countries, cancer is considered to be the second most common cause of death after cardiovascular disease. The clinical management of cancer continues to be a challenge as conventional treatments, such as chemotherapy and radiation therapy, have limitations due to their toxicity profiles. Unhealthy lifestyle and poor dietary habits are the key risk factors for cancer; having a healthy diet and lifestyle may minimize the risk. Epidemiological studies have shown that a high fruit and vegetable intake in our regular diet can effectively reduce the risk of developing certain types of cancers due to the high contents of antioxidants and phytochemicals. In vitro and in vivo studies have shown that phytochemicals exert significant anticancer effects due to their free radical scavenging capacity potential. There has been extensive research on the protective effects of phytochemicals in different types of cancers. This review attempts to give an overview of the etiology of different types of cancers and assesses the role of phytonutrients in the prevention of cancers, which makes the present review distinct from the others available.     

A copper diimine‐based honeycomb‐like porous network as an efficient reduction catalyst

Nitrophenols are among the widely used industrial chemicals worldwide; however, their hazardous effects on environment are a major concern nowadays. Therefore, the conversion of environmentally detrimental p‐nitrophenol (PNP) to industrially valuable p‐aminophenol (PAP), a prototype reaction, is an important organic transformation reaction. However, the traditional conversion of PNP to PAP is an expensive and environmentally unfriendly process. Here, we report a honeycomb‐like porous network with zeolite‐like channels formed by the self‐organization of copper, 1,10‐phenanthroline, 4,4′‐bipyridine, and water. This porous network effectively catalyzed the transformation of hazardous PNP to pharmaceutically valued PAP. In the presence of complex, PNP to PAP conversion occurred in a few minutes, which is otherwise a very sluggish process. To assess the kinetics, the catalytic conversion of PNP to PAP was studied at five different temperatures. The linearity of lnC_t/C_o versus temperature plot indicated pseudo‐first‐order kinetics. The copper complex with zeolite like channels may find applications as a reduction catalyst both on laboratory and industrial scales and in green chemistry for the remediation of pollutants.     

Drier Climatic Conditions Increase Withanolide Content of Withania coagulans Enhancing Its Inhibitory Potential Against Human Prostate Cancer Cells

Applied Biochemistry and Biotechnology - Prostate cancer is one of the major causes of cancer-related deaths in men and there is a growing interest in identifying natural compounds for its...     

Bilinearization and Soliton Solutions of the Supersymmetric Coupled KdV Equation

Theoretical and Mathematical Physics - We propose an N=1 supersymmetric generalization of the coupled Korteweg-de Vries (KdV) equation and use the Hirota superoperator to obtain a superfield...     

Investigation of reconstructed three-dimensional active infrared thermography of buried defects: multiphysics finite elements modelling investigation with initial experimental validation

Journal of Thermal Analysis and Calorimetry - In this paper, we use a Multiphysics approach in COMSOL? Platform to develop and validate a finite element model that simulates thermal images...     

Aldolase Cascade Facilitated by Self‐Assembled Nanotubes from Short Peptide Amphiphiles

Early evolution benefited from a complex network of reactions involving multiple C?C bond forming and breaking events that were critical for primitive metabolism. Nature gradually chose highly evolved and complex enzymes such as lyases to efficiently facilitate C?C bond formation and cleavage with remarkable substrate selectivity. Reported here is a lipidated short peptide which accesses a homogenous nanotubular morphology to efficiently catalyze C?C bond cleavage and formation. This system shows morphology‐dependent catalytic rates, suggesting the formation of a binding pocket and registered enhancements in the presence of the hydrogen‐bond donor tyrosine, which is exploited by extant aldolases. These assemblies showed excellent substrate selectivity and templated the formation of a specific adduct from a pool of possible adducts. The ability to catalyze metabolically relevant cascade transformations suggests the importance of such systems in early evolution.