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81.
Capacity for autonomous self‐fertilization provides reproductive assurance, has evolved repeatedly in the plant kingdom, and typically involves several changes in flower morphology and development (the selfing syndrome). Yet, the relative importance of different traits and trait combinations for efficient selfing and reproductive success in pollinator‐poor environments is poorly known. In a series of experiments, we tested the importance of anther–stigma distance and the less studied trait anther orientation for efficiency of selfing in the perennial herb Arabis alpina. Variation in flower morphology among eight self‐compatible European populations was correlated with efficiency of self‐pollination and with pollen limitation in a common‐garden experiment. To examine whether anther–stigma distance and anther orientation are subject to directional and/or correlational selection, and whether this is because these traits affect pollination success, we planted a segregating F2 population at two native field sites. Selection strongly favored a combination of introrse anthers and reduced anther–stigma distance at a site where pollinator activity was low, and supplemental hand‐pollination demonstrated that this was largely because of their effect on securing self‐pollination. The results suggest that concurrent shifts in more than one trait can be crucial for the evolution of efficient self‐pollination and reproductive assurance in pollinator‐poor habitats.  相似文献   
82.
Three‐dimensional (3D) printing, a layer‐by‐layer deposition technology, has a revolutionary role in a broad range of applications. As an emerging advanced fabrication technology, it has drawn growing interest in the field of electrochemical energy storage because of its inherent advantages including the freeform construction and controllable 3D structural prototyping. This article focuses on the topic of 3D‐printed electrochemical energy storage devices (EESDs), which bridge advanced electrochemical energy storage and future additive manufacturing. Basic 3D printing systems and material considerations are described to provide a fundamental understanding of printing technologies for the fabrication of EESDs. The performance metrics of 3D‐printed EESDs are then given and the related performance optimization strategies are discussed. Next, the recent advances of 3D‐printed EESDs, including sandwich‐type and in‐plane architectures, are summarized. Conclusions and future perspectives with some unique challenges and important directions are then discussed. It can be expected that, with the help of 3D printing technology, the development of advanced electrochemical energy storage systems will be greatly promoted.  相似文献   
83.
We describe two new, mainly North European species of basidiomycetous fungi. Cortinarius stjernegaardii belongs to the section Percomes containing several similar species with greenish-yellow, anthraquinonoid pigments and peculiar smells. The species has hitherto been identified as” C. bulbopodius” in the Nordic countries, an epithet which, however, is reduced to a synonym of C. aurilicis. Cortinarius kristinae belongs to the section Calochroi, which includes many morphologically similar species with sharply marginate bulbose stipes and yellow pileus colours. The species are distinguished from related taxa by molecular data (ribosomal ITS region), and typical specimens can be identified by a combination of basidiocarp coloration, stature, microscopy, reactions with KOH, and habitat.  相似文献   
84.

Background

To our knowledge, no studies of the possible association of early life environment with snoring in adulthood have been published. We aimed to investigate whether early life environment is associated with snoring later in life.

Methods

A questionnaire including snoring frequency in adulthood and environmental factors in early life was obtained from 16,190 randomly selected men and women, aged 25–54 years, in Sweden, Norway, Iceland, Denmark and Estonia (response rate 74%).

Results

A total of 15,556 subjects answered the questions on snoring. Habitual snoring, defined as loud and disturbing snoring at least 3 nights a week, was reported by 18%. Being hospitalized for a respiratory infection before the age of two years (adjusted odds ratio (OR) = 1.27; 95% confidence interval (CI) 1.01–1.59), suffering from recurrent otitis as a child (OR = 1.18; 95%CI 1.05–1.33), growing up in a large family (OR = 1.04; 95%CI 1.002–1.07) and being exposed to a dog at home as a newborn (OR = 1.26; 95%CI 1.12–1.42) were independently related to snoring later in life and independent of a number of possible confounders in adulthood. The same childhood environmental factors except household size were also related with snoring and daytime sleepiness combined.

Conclusion

The predisposition for adult snoring may be partly established early in life. Having had severe airway infections or recurrent otitis in childhood, being exposed to a dog as a newborn and growing up in a large family are environmental factors associated with snoring in adulthood.  相似文献   
85.
Aim We use Cardamine alpina and C. resedifolia as models to address the detailed history of disjunctions in the European alpine system. These species grow on siliceous bedrock: C. alpina in the Alps and Pyrenees, and C. resedifolia in several mountain ranges from the Sierra Nevada to the Balkans. We explore differentiation among their disjunct populations as well as within the contiguous Alpine and Pyrenean ranges, and compare the phylogeographical histories of these diploid sister species. We also include samples of the closely related, arctic diploid C. bellidifolia in order to explore its origin and post‐glacial establishment. Location European alpine system, Norway and Iceland. Methods We employed amplified fragment length polymorphisms (AFLPs). AFLP data were analysed using principal coordinates analysis, neighbour joining and Bayesian clustering, and measures of diversity and differentiation were computed. Results For the snow‐bed species C. alpina (27 populations, 203 plants) we resolved two strongly divergent lineages, corresponding to the Alps and the Pyrenees. Although multiple glacial refugia were invoked in the Pyrenees, we inferred only a single one in the Maritime Alps – from which rapid post‐glacial colonization of the entire Alps occurred, accompanied by a strong founder effect. For C. resedifolia (33 populations, 247 plants), which has a broader ecological amplitude and a wider distribution, the genetic structuring was rather weak and did not correspond to the main geographical disjunctions. This species consists of two widespread and largely sympatric main genetic groups (one of them subdivided into four geographically more restricted groups), and frequent secondary contacts exist between them. Main conclusions The conspicuously different histories of these two sister species are likely to be associated with their different ecologies. The more abundant habitats available for C. resedifolia may have increased the probability of its gradual migration during colder periods and also of successful establishment after long‐distance dispersal, whereas C. alpina has been restricted by its dependence on snow‐beds. Surprisingly, the arctic C. bellidifolia formed a very divergent lineage with little variation, contradicting a scenario of recent, post‐glacial migration from the Alps or Pyrenees.  相似文献   
86.
The disaccharide peracetylated GlcNAcβ1–3Galβ-O-naphthalenemethanol (disaccharide 1) diminishes the formation of the glycan sialyl Lewis X (Neu5Acα2–3Galβ1–4(Fucα1–3) GlcNAc; sLeX) in tumor cells. Previous studies showed that the mechanism of action of disaccharide 1 involves three steps: (i) deacetylation by carboxyesterases, (ii) action as a biosynthetic intermediate for downstream enzymes involved in sLeX assembly, and (iii) generation of several glycans related to sLeX. In this report, we show that GlcNAcβ1–3Galβ-O-naphthalenemethanol binds to the acceptor site of human β1–4-galactosyltransferase much like the acceptor trisaccharide, GlcNAcβ1–2Manβ1–6Man, which is present on N-linked glycans. The 4′-deoxy analog, in which the acceptor hydroxyl group was replaced by -H, did not act as a substrate but instead acted as a competitive inhibitor of the enzyme. The acetylated form of this compound inhibited sLeX formation in U937 monocytic leukemia cells, suggesting that it had inhibitory activity in vivo as well. A series of synthetic acetylated analogs of 1 containing -H, -F, -N3, -NH2, or -OCH3 instead of the hydroxyl groups at C-3′- and C-4′-positions of the terminal N-acetylglucosamine residue also blocked sLeX formation in cells. The reduction of sLeX by the 4′-deoxy analog also diminished experimental tumor metastasis by Lewis lung carcinoma in vivo. These data suggest that nonsubstrate disaccharides have therapeutic potential through their ability to bind to glycosyltransferases in vivo and to alter glycan-dependent pathologic processes.The sialylated, fucosylated tetrasaccharide, sLeX,3 is a common carbohydrate determinant present in many O-GalNAc-linked mucins and N-linked glycans that act as selectin ligands (see Ref. 1 and references therein). Expression of sLeX endows tumor cells with the capacity to bind to platelets and endothelial cells in the vasculature via P- and E-selectins, thus facilitating hematogenous metastasis possibly through protection against innate immune cells and by adhesion to the blood vessel wall. Strategies for blocking selectin-carbohydrate interactions include (i) competition by soluble recombinant forms of selectins, glycoprotein ligands, and glycolipids, (ii) peptides based on the primary sequence of the carbohydrate binding site, (iii) anti-selectin antibodies, (iv) oligosaccharides related to LewisX, (v) inositol polyanions and sulfated sugars, (vi) heparin, and (vii) molecular mimics of sLeX, including oligonucleotides (reviewed in Refs. 2 and 3). Analogs of acceptor substrates of the various glycosyltransferases involved in glycan biosynthesis provide another class of potential inhibitors (reviewed in Refs. 4 and 5). Although many of these analogs are effective in vitro, they generally do not exhibit inhibitory activity in cells due to poor membrane permeability. The large number of polar hydroxyl groups and the lack of membrane transporters for oligosaccharides in most cells presumably prevent their uptake (6).In contrast to many of the inhibitors described above, peracetylated disaccharides (e.g. acetylated Galβ1–4GlcNAcβ-O-naphthalenemethanol (NM), acetylated Galβ1–3GalNAcα-O-NM, and acetylated GlcNAcβ1–3Galβ-O-NM) inhibit sLeX biosynthesis in cells (69). These compounds are taken up by cells by passive diffusion and acted on by cytoplasmic or membrane-associated carboxyesterases, which remove the acetyl groups. The compounds gain access to the biosynthetic enzymes located in the Golgi complex, where they serve as substrates, priming oligosaccharide synthesis and generating products related to O-GalNAc-linked mucin oligosaccharides. Priming in this manner diverts the assembly of the O-linked chains from endogenous glycoproteins, resulting in inhibition of expression of terminal Lewis antigens that are recognized by selectins. Inhibition occurs at a much lower dose than for monosaccharide-based agents, such as GalNAcβ-O-benzyl (∼25 μm versus 1–2 mm, respectively) (10, 11). Furthermore, the disaccharides appear to selectively affect sLeX formation, since sLea expression was unaffected (12). By blocking selectin ligand expression, these compounds block both experimental and spontaneous metastasis (12, 13).In this study, we have examined acetylated disaccharide analogs that have been modified so that after deacetylation their activity as substrates would be altered. Characterization of the 4′-deoxy derivative using β1–4-galactosyltransferase 1 as a model showed that it acts by competitively inhibiting the enzyme. Interestingly, the peracetylated form of this analog maintains the capacity to inhibit sLeX expression in U937 lymphoma cells and Lewis lung carcinoma (LLC) cells and block tumor formation in vivo. Thus, the deoxy analog presumably inhibits one or more galactosyltransferases in vivo, thereby blocking sLeX formation and experimental tumor cell metastasis without generation of oligosaccharide products.  相似文献   
87.

Background

As more inhaled corticosteroid (ICS) devices become available, there may be pressure for health-care providers to switch patients with asthma to cheaper inhaler devices. Our objective was to evaluate impact on asthma control of inhaler device switching without an accompanying consultation in general practice.

Methods

This 2-year retrospective matched cohort study used the UK General Practice Research Database to identify practices where ICS devices were changed without a consultation for ≥5 patients within 3 months. Patients 6–65 years of age from these practices whose ICS device was switched were individually matched with patients using the same ICS device who were not switched. Asthma control over 12 months after the switch was assessed using a composite measure including short-acting β-agonist and oral corticosteroid use, hospitalizations, and subsequent changes to therapy.

Results

A total of 824 patients from 55 practices had a device switch and could be matched. Over half (53%) of device switches were from dry powder to metered-dose inhalers. Fewer patients in switched than matched cohort experienced successful treatment based on the composite measure (20% vs. 34%) and more experienced unsuccessful treatment (51% vs. 38%). After adjusting for possible baseline confounding factors, the odds ratio for treatment success in the switched cohort compared with controls was 0.29 (95% confidence interval [CI], 0.19 to 0.44; p < 0.001) and for unsuccessful treatment was 1.92 (95% CI, 1.47 to 2.56; p < 0.001).

Conclusion

Switching ICS devices without a consultation was associated with worsened asthma control and is therefore inadvisable.  相似文献   
88.
BackgroundAcute Plasmodium vivax malaria is associated with haemolysis, bone marrow suppression, reticulocytopenia, and post-treatment reticulocytosis leading to haemoglobin recovery. Little is known how malaria affects glucose-6-phosphate dehydrogenase (G6PD) activity and whether changes in activity when patients present may lead qualitative tests, like the fluorescent spot test (FST), to misdiagnose G6PD deficient (G6PDd) patients as G6PD normal (G6PDn). Giving primaquine or tafenoquine to such patients could result in severe haemolysis.MethodsWe investigated the G6PD genotype, G6PD enzyme activity over time and the baseline FST phenotype in Cambodians with acute P. vivax malaria treated with 3-day dihydroartemisinin piperaquine and weekly primaquine, 0·75 mg/kg x8 doses.ResultsOf 75 recruited patients (males 63), aged 5–63 years (median 24), 15 were G6PDd males (14 Viangchan, 1 Canton), 3 were G6PD Viangchan heterozygous females, and 57 were G6PDn; 6 patients had α/β-thalassaemia and 26 had HbE.Median (range) Day0 G6PD activities were 0·85 U/g Hb (0·10–1·36) and 11·4 U/g Hb (6·67–16·78) in G6PDd and G6PDn patients, respectively, rising significantly to 1·45 (0·36–5·54, p<0.01) and 12·0 (8·1–17·4, p = 0.04) U/g Hb on Day7, then falling to ~Day0 values by Day56. Day0 G6PD activity did not correlate (p = 0.28) with the Day0 reticulocyte counts but both correlated over time. The FST diagnosed correctly 17/18 G6PDd patients, misclassifying one heterozygous female as G6PDn.ConclusionsIn Cambodia, acute P. vivax malaria did not elevate G6PD activities in our small sample of G6PDd patients to levels that would result in a false normal qualitative test. Low G6PDd enzyme activity at disease presentation increases upon parasite clearance, parallel to reticulocytosis. More work is needed in G6PDd heterozygous females to ascertain the effect of P. vivax on their G6PD activities.Trial registrationThe trial was registered (ACTRN12613000003774) with the Australia New Zealand Clinical trials (https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=363399&isReview=true).  相似文献   
89.
In High Arctic ecosystems, plant growth and reproduction are limited by low soil moisture and nutrient availability, low soil and air temperatures, and a short growing season. Mycorrhizal associations facilitate plant nutrient acquisition and water uptake and may therefore be particularly ecologically important in nutrition‐poor and dry environments, such as parts of the Arctic. Similarly, endophytic root associates are thought to play a protective role, increasing plants' stress tolerance, and likely have an important ecosystem function. Despite the importance of these root‐associated fungi, little is known about their host specificity in the Arctic. We investigated the host specificity of root‐associated fungi in the common, widely distributed arctic plant species Bistorta vivipara, Salix polaris and Dryas octopetala in the High Arctic archipelago Svalbard. High‐throughput sequencing of the internal transcribed spacer 1 (ITS1) amplified from whole root systems generated no evidence of host specificity and no spatial autocorrelation within two 3 m × 3 m sample plots. The lack of spatial structure at small spatial scales indicates that Common Mycelial Networks (CMNs) are rare in marginal arctic environments. Moreover, no significant differences in fungal OTU richness were observed across the three plant species, although their root system characteristics (size, biomass) differed considerably. Reasons for lack of host specificity could be that association with generalist fungi may allow arctic plants to more rapidly and easily colonize newly available habitats, and it may be favourable to establish symbiotic relationships with fungi possessing different physiological attributes.  相似文献   
90.
Chen  Ying  Klingen  Tor A  Wik  Elisabeth  Aas  Hans  Vigeland  Einar  Liestøl  Knut  Garred  Øystein  Mæhlen  Jan  Akslen  Lars A  Lømo  Jon 《Diagnostic pathology》2014,9(1):1-2
Squamous cell carcinomas (SCCs) are uncommon, high-grade tumors, predominantly composed of round cells in the prepuce. The aim of this study is to better define the clinicopathologic features of this neoplasm. We conducted cyto-histopathologic analysis on the manifestations of the prepuce SCC by H &; E staining in a terrier mix dog. Grossly, tumor was large, multiple erythematous patch, and ulcerated masses frequently affecting the prepuce and deeply invading to distal prepuce out from the ventro-lateral of penis and the tumor covered by a necrotic discharge. Cytological evaluation of fine-needle aspirates from the cutaneous mass from the prepuce comprised of round nuclei, coarse chromatin pattern, distinct nucleoli and nuclear pleomorphism. Furthermore, the neoplastic cells were pleomorphic, round to caudate in shape, exhibiting prominent anisokaryosis and anisocytosis with rare mitotic features. Microscopically, the lesions were predominantly composed of atypical round cells disposed in interlacing fascicles. Frequent findings include keratin formation, horn pearls, mitoses and cellular atypia. The cells showed distinct borders, ranged from polygonal to round or elongate and had moderate amounts of eosinophilic cytoplasm. The histopathologic features coupled with the cytopathology findings led to a diagnosis of squamous cell carcinoma. To the authors’ knowledge, this is the first time that multiple erythematous plaques have undergone malignant transformation in a terrier mix dog. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5748771971272873  相似文献   
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