Naturally-occurring radioactive material (NORM) is the term used to describe materials containing radionuclides that exist in the natural environment. The radionuclides of interest include long-lived radionuclides such as uranium-238 (238U), uranium-235 (235U) and thorium-232 (232Th) and their radioactive decay products (such as isotopes of radium, radon, polonium, bismuth and lead), and individual long-lived radionuclides such aspotassium-40 (40K), rubidium-87 (87Rb) and indium-115 (115In). The parent radionuclides have decay times (half-lives) which are comparable with or larger than the age of the earth, so they have always been present in the earth’s crust and within the tissues of all living species. Where materials contain radionuclides from the naturally occurring decay chains (238U, 235U, 232Th), the large number of radionuclides in each chain, and the resulting large range of physical and chemical properties of the individual radionuclides, means that there can be a highly variable degree of secular equilibrium between the individual members of the chains

Naturally occurring bacteria, is exist in nature, and is never cultivated on conventional culture medium. We evaluated the efficacy of disinfectants against naturally occurring bacteria in in-use cotton balls soaked in 0.02% benzalkonium chloride solution which had been used to disinfect the genital area by patients undergoing self-catheterization at home and the same bacteria subcultured on nutrient broth (artificially cultivated bacteria). The colony forming units (CFU) of naturally occurring bacteria such as Serratia marcescens, Alcaligenes xylosoxidans, and Burkholderia cepacia were not decreased after 48 h exposure to 0.025-0.1% benzalkonium chloride solution, but the same strains subcultured on nutrient broth were killed within only 10 min exposure to 0.025-0.1% benzalkonium chloride solution. In addition, the CFU of these three kinds of naturally occurring bacteria were not decreased after 48 h exposure to 0.02% chlorhexidine gluconate solution, but the same strains subcultured on nutrient broth were killed within 2 h exposure to chlorhexidine gluconate solution. The result showed that disinfectant efficacy differed markedly against naturally occurring and artificially cultivated bacteria. Therefore, it is preferable to use the naturally occurring bacteria not only artificially cultivated bacteria when examining disinfectant efficacy.

The effect of the naturally occurring crosslinking junctions on green strength of natural rubber, isolated from Hevea brasiliensis, was investigated by using rubber extracted from Parthenium argentatum Gray (Guayule) as a model. Guayule rubber and natural rubber were characterized through nuclear magnetic resonance spectroscopy and size exclusion chromatography. The non‐rubber components of Guayule rubber and natural rubber were characterized by Kjeldahl method and Fourier transform infrared spectroscopy. It was found that Guayule rubber contains a much higher amount of fatty acids and their esters while it contains no proteins. The gel content, determined by swelling method, was related to a number of naturally occurring crosslinking junctions of Guayule rubber and natural rubber. The outstanding green strength of natural rubber was attributed to the effect of naturally occurring crosslinking junctions, when stress–strain curve and tensile properties of unvulcanized Guayule rubber were compared with those of unvulcanized natural rubber. Copyright © 2016 John Wiley & Sons, Ltd.

Diarylheptanoids, natural products with a 1,7-diphenylheptane structural skeleton, are mainly distributed in the roots, rhizomes and bark of Alpinia, Zingiber, Curcuma and Alnus species. They have become of interest in natural product research over the past twenty years because of their remarkable anti-cancer, anti-emetic, estrogenic, anti-microbial and anti-oxidant activity. This paper compiles all 307 naturally occurring diarylheptanoids from 46 plants as reported in 137 references with their distributions, physiological activities and 13C-NMR spectral data.

Polyploidy is a significant evolutionary process in plants that involves the duplication of genomic content and has been recognized as a key mechanism driving plant diversification and adaptation. In natural populations, polyploids frequently arise from unreduced gametes, which subsequently fuse with reduced or unreduced gametes, resulting in triploid or tetraploid offspring, respectively. Cannabis sativa L. is a diploid species, but recent work using artificially induced polyploidy has demonstrated its potential advantages in an agricultural setting. Further, recent work has identified that some elite clonal cultivars, vis. Mac1, are triploid, with no indication that they were artificially produced. The current study was conducted to determine if polyploidy is a naturally occurring phenomenon in cannabis and to estimate the frequency of this phenomenon across populations. To do this, the presence of natural triploid individuals was evaluated in 13 seedling populations of cannabis using a flow cytometry analysis. Among the examined populations, natural triploids were identified in 10 groups with an average frequency of approximately 0.5%. The highest frequency of natural triploids was observed in a self-pollinated population at 2.3%. This research demonstrates that polyploidy is a naturally occurring event in cannabis and triploids are present at an average of approximately 0.5%, or 1 in 200 plants. These data shed light on the natural variation in ploidy within cannabis populations and contribute valuable insights to the understanding of cannabis genetics and breeding practices.

The development of a novel repellent plays an important role in the integrated control of Blattella germanica. A series of novel hydronopylformamides derivatives were synthesized from a naturally occurring compound (-)-β-pinene. The structures of these hydronopylformamides derivatives were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (1H-NMR and 13C-NMR), and electron impact mass spectrometry (EI-MS). Repellency of these hydronopylformamides derivatives against Blattella germanica was evaluated by the using petri dish arena method. The results showed that four derivatives (compounds 8a, 8b, 8c and 8e) exhibited repellency against Blattella germanica at a concentration of 20 mg/mL. Compound 8a was the most active compound among these derivatives, where the repelling ratios of compound 8a against Blattella germanica were 66.10%, 50.46%, 48.26%, at concentrations of 20 mg/mL, 10 mg/mL, and 5 mg/mL, respectively. In addition, compound 8a showed better repellency than the traditional insect repellent N, N-diethyl-3-methylbenzamide (DEET), which indicated that compound 8a had a good application prospect in the prevention of Blattella germanica. This research hopes to promote the value-added utilization of (-)-β-pinene and the development of novel German cockroach repellents.

Sustained abstinence from cocaine use is frequently compromised by exposure to environmental stimuli that have previously been strongly associated with drug taking. Such cues trigger memories of the effects of the drug, leading to craving and potential relapse. Our work has demonstrated that manipulating cocaine-cue memories by destabilizing them through interfering with the reconsolidation process is one potential therapeutic tool by which to prolong abstinence. Here, we examine the use of the naturally occurring amnestic agent garcinol to manipulate an established cocaine-cue memory. Rats underwent 12 days of cocaine self-administration training during which time active lever presses resulted in an i.v. infusion of cocaine that was paired with a light/tone cue. Next rats underwent lever extinction for 8 days followed by light/tone reactivation and a test of cue-induced cocaine-seeking behavior. Systemic injection of garcinol 30 min after reactivation significantly impaired the reconsolidation of the cocaine-associated cue memory. Further testing revealed that garcinol had no effect on drug-induced cocaine-seeking, but was capable of blocking the initial conditioned reinforcing properties of the cue and prevents the acquisition of a new response. Additional experiments showed that the effects of garcinol are specific to reactivated memories only, temporally constrained, cue-specific, long-lasting, and persist following extended cocaine access. These data provide strong evidence that the naturally occurring compound, garcinol, may be a potentially useful tool to sustain abstinence from drug abuse.

The absolute configuration of picrasidine Y, a β-carboline alkaloid isolated from Picrasma quassioides (Simaroubaceae), has not been determined. To determine the absolute configuration of picrasidine Y, we synthesized stereoisomers of picrasidine Y through 7-step chemical reactions using tartaric acid as a starting material. Moreover, we extended the scope of application of this synthetic method to canthin-5,6-dione compounds. The absolute configuration of natural picrasidine Y was elucidated based on comparisons of chemically synthesized isoforms with the naturally occurring compound in 1H and 13C NMR spectra, specific optical rotation, HPLC analysis with chiral columns, computational molecular simulation, and analysis with the CD exciton chirality method.

This article reviews the current progresses in application of both exogenous and endogenous progenitor cells/stem cells for cardiac repair, and the current understanding of the naturally-occurring process for physiological myocyte turnover and possibly cardiac repair. In particular the development of methods for potentiating the naturally-occurring mechanism for substantial repair of pathologically damaged cardiac tissues is discussed. In the last decade, tremendous efforts to identify both exogenous and endogenous progenitor cells/stem cells possessing capacities of differentiating into cardiac lineages have been made for potential cardiac repair. Although many impressive progresses have been made in the application of differently sourced progenitor cells/stem cells, such as embryonic stem cells (ESCs), induced pluripotent stem cell (iPS), bone marrow-derived mesenchymal stem cells (MSCs), skeletal myoblasts (SMs), umbilical cord blood cells (UCBs), residential cardiac stem cells (CSCs), cardiac resident fibroblasts (CRFs), or adipose tissue-derived stem cells (ASCs) for repair of damaged heart, however, inevitable controversies exist concerning: (i) the immune compatibility of the exogenous donor progenitors/stem cells, (ii) the tumorigenicity with ESCs and iPS, and (iii) the efficiency of these exogenous or endogenous progenitors/ stem cells to acquire cardiac lineages to reconstitute the lost cardiac tissues. The recent recognition of some active small molecules that can induce myocardial regeneration to repair damaged heart tissues through enhancing the naturally-occurring cardiac-repair mechanism has offered the hope for clinical translation of the technology. Potentiating the naturally-occurring process for cardiac repair by administration of such small molecules has provided a promising strategy for reconstruction of damaged cardiac tissues after heart infarction. Therefore, this article is in favor of the notion that such small molecules with the activity of manipulating gene expressions in such a way of inducing endogenous stem cells to commit cardiac lineage differentiation and consequently myocardial regeneration may fulfill the dream of substantial repair of damaged heart.

Conjugation is considered the main horizontal gene transfer mechanism in bacterial adaptation and evolution. In the Mycobacteriaceae family, Mycolicibacterium smegmatis has been used as the model organism for the conjugative transfer of hybrid plasmids. However, the natural conjugation process in any bacteria would involve the transfer of naturally occurring plasmids. Currently, there is a gap in this regard about this abundant environmental genus of Mycobacteriaceae. Here, we performed conjugation experiments between wild Mycolicibacterium sp. strains involving naturally occurring plasmids, and interestingly, evidence of conjugative transfer was obtained. Thus, it is likely that conjugation occurs in Mycolicibacterium in the natural environment, representing a source of diversification and evolution in this genus of bacteria.