The effects of ascorbic acid on salt induced alfalfa (Medicago sativa L.) in in vitro culture

Ascorbic acid as an antioxidant agent has already been used for increasing of stress tolerance. Callus was produced from stem segments of alfalfa (Medicago sativa L.) on MS medium supplemented with 2,4 dichlorophenoxy acetic acid, naphthalene acetic acid and kinetin (2 mg/leach).Calli were then transferred to the same medium containing 0, 30, 60, 90, 120 mM NaCl and 0, 0.5, 1.0, 2.0 mM ascorbic acid. Addition of ascorbic acid to the medium improved seed germination and also increased the activity of acid phosphates, chlorophyll content, and drymass. The Na+ and K+ content of stem-leaf and root was relatively increased with some variations. The fresh weight of calli was also increased by ascorbic acid under salt stress conditio

Estudio en laboratorio sobre licuefacción de arena parcialmente saturada

This experimental study was designed to assess the effects of soil water saturation on the liquefaction of Hostun RF sand. Cyclic undrained triaxial tests were conducted at different soil saturation levels, as given by Skempton’s coefficient, and liquefaction potential curves constructed for each value of this coefficient. Our findings indicate that a lower soil saturation level results in the increased resistance of the sand to liquefaction, in agreement with the tendency observed in other sands. In addition, the variation in sand resistance to liquefaction produced with Skempton’s coefficient was found to be consistent with the semi-empirical relation proposed by Yang et al. (2004).Este estudio experimental fue diseñado para comprobar los efectos de la saturación de agua en suelos bajo la licuefacción de arena RF Hostun. Tests cíclicos de tipo triaxial no drenado fueron elaborados a diferentes niveles de saturación del suelo, como se obtiene por el coeficiente de Skempton, y se obtuvieron curvas de potencial de licuefacción para cada uno de los valores de este coeficiente. Nuestros resultados indican que un nivel de saturación bajo de suelo durante el incremento de la resistencia de la arena a la licuefacción, estando de acuerdo con la tendencia observada en otras arenas. Por otro lado, se observó que la variación de la resistencia de las arenas a la licuefacción producida mediante el coeficiente de Skempton es consistente con la relación semiempírica propuesta por Yang et al. (2004)

Consequences of Aberrant Insulin Regulation in the Brain: Can Treating Diabetes be Effective for Alzheimer’s Disease

There is an urgent need for new ways to treat Alzheimer’s disease (AD), the most common cause of dementia in the elderly. Current therapies are modestly effective at treating the symptoms, and do not significantly alter the course of the disease. Over the years, a range of epidemiological and experimental studies have demonstrated interactions between diabetes mellitus and AD. As both diseases are leading causes of morbidity and mortality in the elderly and are frequent co-morbid conditions, it has raised the possibility that treating diabetes might be effective in slowing AD. This is currently being attempted with drugs such as the insulin sensitizer rosiglitazone. These two diseases share many clinical and biochemical features, such as elevated oxidative stress, vascular dysfunction, amyloidogenesis and impaired glucose metabolism suggesting common pathogenic mechanisms. The main thrust of this review will be to explore the evidence from a pathological point of view to determine whether diabetes can cause or exacerbate AD. This was supported by a number of animal models of AD that have been shown to have enhanced pathology when diabetic conditions were induced. The one drawback in linking diabetes and insulin to AD has been the postmortem studies of diabetic brains demonstrating that AD pathology was not increased; in fact decreased pathology has often been reported. In addition, diabetes induces its own distinct features of neuropathology different from AD. There are common pathological features to be considered including vascular abnormalities, a major feature arising from diabetes; there is increasing evidence that vascular abnormalities can contribute to AD. The most important common mechanism between insulin-resistant (type II) diabetes and AD could be impaired insulin signaling; a form of toxic amyloid can damage neuronal insulin receptors and affect insulin signaling and cell survival. It has even been suggested that AD could be considered as “type 3 diabetes” since insulin can be produced in brain. Another common feature of diabetes and AD are increased advanced glycation endproduct-modified proteins are found in diabetes and in the AD brain; the receptor for advanced glycation endproducts plays a prominent role in both diseases. In addition, a major role for insulin degrading enzyme in the degradation of Aβ peptide has been identified. Although clinical trials of certain types of diabetic medications for treatment of AD have been conducted, further understanding the common pathological processes of diabetes and AD are needed to determine whether these diseases share common therapeutic targets

Monoclinic superstructure in the orthorhombic Ce10W22O81 from transmission electron microscopy

International audienceA complex rare earth tungstate structure, present in a two-phased powder, was solved by electron diffraction, precession and high resolution electron microscopy. The orthorhombic space group Pbnm and the atomic positions deduced from X-rays diffraction experiments were confirmed for Ce10W22O81. A C2/c monoclinic superstructure, with cell parameters a = 7.8 Å, b = 36.1 Å, c = 22.2 Å and β = 100.2°, was evidenced and attributed to a partial oxidation of Ce3+ leading to interstitial oxygen ions

Tea consumption and the reduced risk of colon cancer – results from a national prospective cohort study

OBJECTIVE: This study examines the relationship between tea consumption and colon cancer risk in the US population. DESIGN: Data from the NHANES I Epidemiologic Follow-up study (NHEFS) were used to examine the hypothesis. Cox proportional hazard models were used to examine the hypothesis of a protective effect of frequent tea consumption on colon cancer occurrence. SETTING: Due to differences in the precision of the exposure data, we analysed two cohort periods based on the NHEFS. Cohort I was based on the survey conducted at the NHEFS baseline and Cohort II began at the first follow-up. SUBJECTS: After excluding non-incidence cases and cases lost to follow-ups, there were 2359 tea users and 6498 non-tea users at baseline and 7656 tea users and 4514 non-tea users at the first follow-up. RESULTS: : After adjusting for confounders, the relative risks of colon cancer are 0.57 (95% confidence interval (CI) 0.42, 0.78) and 0.59 (95% 1.00) for subjects who consumed 1.5 cups per day, respectively, compared with non-tea users in Cohort II. Although more women consumed tea and the mean intake was higher, the preventive effect of tea consumption on colon cancer was found predominantly in men. The relative risks of colon cancer are 0.41 (95% 0.66) for men who consumed 1.5 cups day-1 of tea consumption (P-value for trend <0.01). No significant results were found in Cohort I. CONCLUSIONS: This study suggests an inverse association between colon cancer risk and habitual tea consumption

Vesical schistosomiasis and squamous cell carcinoma associated with schistosoma haematobium: A re-emerging neglected tropical disease in Tehran, Iran

Hematobium species of this parasite tends to bladder and mesenteric arteries and it causes lesions in the bladder wall, urethra, and renal tubes. A 25-year-old man living in Tehran (a non-endemic and very rare area for schistosoma) suffers from symptoms such as hematuria with suprapubic pain, dysuria, fever, nausea and vomiting. Urine analysis showed a lot of red blood cells, after using cystoscopy of the area and receiving a bladder biopsy, a definitive diagnosis of schistosomiasis was made and after determining the extent of damage to the urinary tract, appropriate treatment with surgery and praziquantel (40 mg/kg) were prescribed. © 202

Accelerating Universe from an Evolving Lambda in Higher Dimension

We find exact solutions in five dimensional inhomogeneous matter dominated model with a varying cosmological constant. Adjusting arbitrary constants of integration one can also achieve acceleration in our model. Aside from an initial singularity our spacetime is regular everywhere including the centre of the inhomogeneous distribution. We also study the analogous homogeneous universe in (4+d) dimensions. Here an initially decelerating model is found to give late acceleration in conformity with the current observational demands. We also find that both anisotropy and number of dimensions have a role to play in determining the time of flip, in fact the flip is delayed in multidimensional models. Some astrophysical parameters like the age, luminosity distance etc are also calculated and the influence of extra dimensions is briefly discussed. Interestingly our model yields a larger age of the universe compared to many other quintessential models.Comment: 18 pages, 9 figure