Determination of in vitro antidiabetic effects of Zingiber officinale Roscoe

Aqueous extracts of Zingiber officinale rhizomes were studied to evaluate their antidiabetic effects on protein glycation and on the diffusion of glucose in vitro in the present study. Zingiber officinale rhizome aqueous extract were examined at concentrations of 5, 10, 20 and 40 g/L. The antidiabetic effects were found to be dose-dependent. Antidiabetic potential of Zingiber officinale was mainly through inhibition of the glucose diffusion and to a limited extent by reducing the glycation. However, further studies are needed to determine in vitro effects of therapeutic potential by restraining postprandial glucose absorptions and plasma protein glycations in diabetic subjects.Extratos aquosos de rizomas Zingiber officinale foram estudados para avaliar os seus efeitos antidiabéticos em glicação de proteínas e sobre a difusão de glicose in vitro, no presente estudo. Extratos aquosos de Zingiber officinale foram examinados nas concentrações de 5, 10, 20 e 40 g extrato de planta/L. Os efeitos antidiabéticos observados eram dependentes da dose. O potencial antidiabético de Zingiber officinale se verificou, principalmente, através da inibição da difusão de glicose e, em menor extensão, através da redução da glicação. Estudos adicionais são necessários para elucidar se efeitos in vitro representam potencial terapêutico, restringindo a absorção de glicose pós-prandial e a glicação de proteínas plasmáticas em indivíduos diabéticos

On the density of cyclic quartic fields

An asymptotic formula is obtained for the number of cyclic quartic fields over Q with discriminant ≤ x

Small solutions of φ1x2 1 + ⋯ + φnx2 n = 0

Let φ1, . . . , φn (n ≥ 2) be nonzero integers such that the equation ∑n i=1 φix2 i = 0 is solvable in integers x1, . . . , xn not all zero. It is shown that there exists a solution satisfying 0 < ∑n i=1 |φi|x2 i ≤ 2|φ1 ⋯ φn|, and that the constant 2 is best possible

Temperature variation at the low-latitude regions of East Asia recorded by tree rings during the past six centuries

The understanding of past millennium climate change is very important. Due to the lack of continuously annual resolution records, the temperature characteristics in the low-latitude regions of East Asia (LLREA) during past several centuries are still unknown. Using tree-ring width chronology from Taiwan, an island located in the western Pacific region and in southeastern China, February-October mean temperature from 1380 to 2007 AD was reconstructed. Spatial correlation analysis indicated that the reconstructed temperature could represent the sea-land temperature change in LLREA. During the past six centuries, both the warmest intervals and the largest variability of temperature appeared in the twentieth century. This is probably related to human activities. Temperature in LLREA provided good contrast with temperature changes in the Tibet Plateau and elsewhere in the Northern Hemisphere. The LLREA entered into the Little Ice Age around the year of 1450, approximately 100 years earlier than the Tibet Plateau. The 10-year cycle contained in the reconstructed temperature is close to the 11-year period of solar activity, which revealed there was a certain relationship between them. The temperature in LLREA significantly correlated with solar activity at the decadal to centennial scales. The strong/weak solar irradiance corresponded to the great/small temperature variability

The Ediacaran Aspidella-type impressions in the Jinxian successions of Liaoning Province, northeastern China

We identify the macroscopic impression fossils from the Xingmincun Formation of the Jinxian Group, Liaoning Province of northeastern China as members of the Aspidella plexus of the Ediacaran age. This is the first recognition of the taxon in the Liaoning Province, although such fossils have been previously recorded in the succession but were referred to as new species and relegated to an earlier Neoproterozoic age. A revision of the taxonomic interpretation and relative age estimation of the previous record is provided as well as an evaluation of abiotic vs biotic processes that could produce similar structures to studied impressions. We consider the mode of preservation of the fossils from a biochemical point of view and the properties of organic matter in the integument of soft-bodied metazoans. The selective preservation of the Ediacaran organisms, including metazoans, as impressions (moulds and casts) against the organically preserved contemporaneous cyanobacterial and algal microfossils and an exceptionally small number of terminal Ediacaran metazoan fossils (Sabellidites, Conotubus and Shaanxilites), demonstrates the non-resistant characteristics and the very different biochemical constitution of the Ediacaran metazoans compared with those that evolved in the Cambrian and after. The refractory biomacromolecules in cell walls of photosynthesizing microbiota (bacterans, cutans, algaenan and sporopollenin groups) and in the chitinous body walls of Sabellidites sharply contrast to the labile biopolymers in Ediacaran metazoans known only from impressions. The newly emerging biosynthesis of resistant biopolymers in metazoans (chitin and collagen groups) initiated by the annelids at the end of Ediacaran and fully evolved in Cambrian metazoans, considered with the ability to biomineralize, made their body preservation possible. The Chengjiang and Burgess Shale metazoans show evidence of this new biochemistry in body walls and cuticles, and not only because of the specific taphonomic window that enhanced their preservation.Divergence of Proterozoic-Cambrian phytoplankton and timing of the symbiotic origins of chlorophyte alga