A new species of Mallomonas, M. nuussuaqensis was found to be common in samples collected from waterbodies on Nuussuaq/Nûgssuaq (70N-71N, West Greenland). The species has very compact silica scales with a thick broad marginal rim and a very thick and broad hood, which often occupies more than two thirds of the shield. 相似文献
The introduction of invasive species that can replace native species is one of the most critical threats to the biodiversity of aquatic systems. Here we investigated the potential contribution of one factor to the coexistence of the indigenous amphipod Gammarus roeselii and the invasive amphipod Dikerogammarus villosus in the same ecosystem (Lake Constance) within different microhabitats. We quantitatively studied the influence of ambient ammonia concentrations on the distributions of the two amphipod species. We also assessed the ammonia tolerance ranges of both species in laboratory experiments by measuring mortality rate, precopula disruption, egg mortality, and microhabitat choice. The proportion of G. roeselii among the two amphipod species was significantly positively related to the ammonia concentration in the water, which indicated that the distribution of the invasive D. villosus was limited at high ammonia concentrations. Although the mortality rates of the two species did not significantly differ, G. roeselii was more tolerant to ammonia with regard to precopula disruption, egg mortality, and microhabitat choice. The effective ammonia concentrations that led to a significantly reduced direct reproductive success in D. villosus were within the range of the highest field concentrations measured, where only G. roeselii occurred. D. villosus may have a smaller range than the indigenous G. roeselii partially because of its lower tolerance to higher ammonia concentrations, which lead to reduced reproductive success. Beside other habitat parameters differences on ammonia tolerance between the two amphipods might allow their coexistence along a gradient of microhabitats in Lake Constance. 相似文献
Summary
Pleurotus florida was grown in submerged culture with different concentrations of sugar beet pulp with a view to its nutritional upgrading.
Micelial growth, protein enrichment and dry weight loss of the solid residues of cultures, as well as the evolution of reducing
sugars in the liquid medium, were followed for 14 days. A product with 45% (w/w) protein and a saccharification extent as
high as 35% (w/w) were obtained after 7 days with 1% (w/v) sugar beet pulp. 相似文献
Findings from prior studies of possible health and physiological effects from mobile phone use have been inconsistent. Exposure periods in provocation studies have been rather short and personal characteristics of the participants poorly defined. We studied the effect of radiofrequency field (RF) on self-reported symptoms and detection of fields after a prolonged exposure time and with a well defined study group including subjects reporting symptoms attributed to mobile phone use. The design was a double blind, cross-over provocation study testing a 3-h long GSM handset exposure versus sham. The study group was 71 subjects age 18-45, including 38 subjects reporting headache or vertigo in relation to mobile phone use (symptom group) and 33 non-symptomatic subjects. Symptoms were scored on a 7-point Likert scale before, after 1(1/2) and 2(3/4) h of exposure. Subjects reported their belief of actual exposure status. The results showed that headache was more commonly reported after RF exposure than sham, mainly due to an increase in the non-symptom group. Neither group could detect RF exposure better than by chance. A belief that the RF exposure had been active was associated with skin symptoms. The higher prevalence of headache in the non-symptom group towards the end of RF exposure justifies further investigation of possible physiological correlates. The current study indicates a need to better characterize study participants in mobile phone exposure studies and differences between symptom and non-symptom groups. 相似文献
A recombinant mouse methionine-r-sulfoxide reductase 2 (MsrB2ΔS) isotopically labeled with 15N and 15N/13C was generated. We report here the 1H, 15N, and 13C NMR assignments of the reduced form of this protein.
An erratum to this article can be found at 相似文献
During keratinocyte differentiation and stratification, cells undergo extensive remodeling of their actin cytoskeleton, which is important to control cell mobility and to coordinate and stabilize adhesive structures necessary for functional epithelia. Limited knowledge exists on how the actin cytoskeleton is remodeled in epithelial stratification and whether cell shape is a key determinant to trigger terminal differentiation. In this paper, using human keratinocytes and mouse epidermis as models, we implicate miR-24 in actin adhesion dynamics and demonstrate that miR-24 directly controls actin cable formation and cell mobility. miR-24 overexpression in proliferating cells was sufficient to trigger keratinocyte differentiation both in vitro and in vivo and directly repressed cytoskeletal modulators (PAK4, Tks5, and ArhGAP19). Silencing of these targets recapitulated the effects of miR-24 overexpression. Our results uncover a new regulatory pathway involving a differentiation-promoting microribonucleic acid that regulates actin adhesion dynamics in human and mouse epidermis. 相似文献
This study evaluates the safety, principal feasibility and restoration potential of laser-supported CD133+ intramyocardial cell transplantation in patients with ischemic cardiomyopathy.
Methods
Forty-two patients with severe ischemic cardiomyopathy (left ventricular ejection fraction (LVEF) >15% and <35%) were included in this prospective multicenter phase I trial. They underwent coronary artery bypass grafting (CABG) with subsequent transepicardial low-energy laser treatment and autologous CD133+ cell transplantation, and were followed up for 12 months. To evaluate segmental myocardial contractility as well as perfusion and to identify the areas of scar tissue, cardiac MRI was performed at 6 months and compared to the preoperative baseline. In addition, clinical assessment comprising of CCS scoring, blood and physical examination was performed at 3, 6 and 12 months, respectively.
Results
Intraoperative cell isolation resulted in a mean cell count of 9.7±1.2×106. Laser treatment and subsequent CD133+ cell therapy were successfully and safely carried out in all patients and no procedure-related complications occurred. At 6 months, the LVEF was significantly increased (29.7±1.9% versus 24.6±1.5% with p = 0.004). In addition, freedom from angina was achieved, and quality of life significantly improved after therapy (p<0.0001). Interestingly, an extended area of transmural delayed enhancement (>3 myocardial segments) determined in the preoperative MRI was inversely correlated with a LVEF increase after laser-supported cell therapy (p = 0.024).
Conclusions
This multicenter trial demonstrates that laser-supported CD133+ cell transplantation is safe and feasible in patients with ischemic cardiomyopathy undergoing CABG, and in most cases, it appears to significantly improve the myocardial function. Importantly, our data show that the beneficial effect was significantly related to the extent of transmural delayed enhancement, suggesting that MRI-guided selection of patients is mandatory to ensure the effectiveness of the therapy.
This study was performed to evaluate and compare the effects of estradiol sulfamate (J995) and estradiol (E2) on the hepatic levels of the estrogen receptor (ER) and its mRNA, in ovariectomized (OVX) and OVX+hypophysectomized (OVXHX) female rats and to study the effects on the liver-derived serum compounds angiotensin I, triglycerides, high-density lipoprotein (HDL) and cholesterol. ER concentrations were determined using ligand-binding assay (LBA) and enzyme immuno assay (EIA), and the mRNA levels using solution hybridization.
The rats were treated orally (p.o.) or subcutaneously (s.c.) for 7 days, with treatments initiated 14 days after surgery.
No differences were found in ER mRNA levels between J995 and E2 treated rats.
The s.c. administered estrogens increased ER levels in OVX rats. Addition of GH+DEX to OVXHX rats restored the ER to levels above those seen in intact rats, whereas simultaneous oral treatment with E2 significantly decreased ER levels again. The s.c. treatment with either J995 or E2 limited the increase caused by addition of GH+DEX.
After oral treatment angiotensin I levels were increased by E2, but not by J995, while triglycerides, HDL and cholesterol levels were decreased by oral E2, J995 showing a similar pattern but was less effective.
In summary, these results on hepatic ER levels and estrogen dependent compounds produced by the liver showed that J995 has a lower impact on the normal liver functions after oral treatment than E2. Thus, J995 is a very promising substance for development of oral estrogen treatment with reduced hepatic side effects. 相似文献