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71.
The skin is a dynamic organ whose complex material properties are capable of withstanding continuous mechanical stress while accommodating insults and organism growth. Moreover, synchronized hair cycles, comprising waves of hair growth, regression and rest, are accompanied by dramatic fluctuations in skin thickness in mice. Whether such structural changes alter skin mechanics is unknown. Mouse models are extensively used to study skin biology and pathophysiology, including aging, UV-induced skin damage and somatosensory signaling. As the skin serves a pivotal role in the transfer function from sensory stimuli to neuronal signaling, we sought to define the mechanical properties of mouse skin over a range of normal physiological states. Skin thickness, stiffness and modulus were quantitatively surveyed in adult, female mice (Mus musculus). These measures were analyzed under uniaxial compression, which is relevant for touch reception and compression injuries, rather than tension, which is typically used to analyze skin mechanics. Compression tests were performed with 105 full-thickness, freshly isolated specimens from the hairy skin of the hind limb. Physiological variables included body weight, hair-cycle stage, maturity level, skin site and individual animal differences. Skin thickness and stiffness were dominated by hair-cycle stage at young (6–10 weeks) and intermediate (13–19 weeks) adult ages but by body weight in mature mice (26–34 weeks). Interestingly, stiffness varied inversely with thickness so that hyperelastic modulus was consistent across hair-cycle stages and body weights. By contrast, the mechanics of hairy skin differs markedly with anatomical location. In particular, skin containing fascial structures such as nerves and blood vessels showed significantly greater modulus than adjacent sites. Collectively, this systematic survey indicates that, although its structure changes dramatically throughout adult life, mouse skin at a given location maintains a constant elastic modulus to compression throughout normal physiological stages.  相似文献   
72.
Preclinical studies of animals with risk factors, and how those risk factors contribute to the development of cardiovascular disease and cardiac dysfunction, are clearly needed. One such approach is to feed mice a diet rich in fat (i.e. 60%). Here, we determined whether a high fat diet was sufficient to induce cardiac dysfunction in mice. We subjected mice to two different high fat diets (lard or milk as fat source) and followed them for over six months and found no significant decrement in cardiac function (via echocardiography), despite robust adiposity and impaired glucose disposal. We next determined whether antecedent and concomitant exposure to high fat diet (lard) altered the murine heart’s response to infarct-induced heart failure; high fat feeding during, or before and during, heart failure did not significantly exacerbate cardiac dysfunction. Given the lack of a robust effect on cardiac dysfunction with high fat feeding, we then examined a commonly used mouse model of overt diabetes, hyperglycemia, and obesity (db/db mice). db/db mice (or STZ treated wild-type mice) subjected to pressure overload exhibited no significant exacerbation of cardiac dysfunction; however, ischemia-reperfusion injury significantly depressed cardiac function in db/db mice compared to their non-diabetic littermates. Thus, we were able to document a negative influence of a risk factor in a relevant cardiovascular disease model; however, this did not involve exposure to a high fat diet. High fat diet, obesity, or hyperglycemia does not necessarily induce cardiac dysfunction in mice. Although many investigators use such diabetes/obesity models to understand cardiac defects related to risk factors, this study, along with those from several other groups, serves as a cautionary note regarding the use of murine models of diabetes and obesity in the context of heart failure.  相似文献   
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Tubiphytes Maslov (Nigriporella Rigby, Shamovella Rauser-Chernoussova) and similar organisms belong to one of the most abundant, enigmatic fossils reported from Carboniferous to Cretaceous rocks of numerous localities worldwide. Tubiphytes has been referred to many distinctly different organisms of the Tethys occurring in shallow water, particularly reef biotopes. Paleozoic Tubiphytes were revised by Senowbari-Daryan and Flügel, and Jurassic-Cretaceous species by Senowbari-Daryan et al. In this paper, the Triassic representatives of Tubiphytes and Tubiphytes-like organisms are described. The morphological and structural differences between the Paleozoic and Triassic Tubiphytes are shown and their systematic position is discussed. The following new species are described: Tubiphytes carnicus, T. ramosus, T. alcicornis, and Plexoramea cylindrica. The new genus Carniphytes is proposed for Tubiphytes multisiphonatus Schäfer and Senowbari-Daryan. Tubiphytes gracilis Schäfer and Senowbari-Daryan is transferred to the genus Plexoramea Mello. All described taxa are relatively abundant in Ladinian-Carnian reefs (e.g., “Wetterstein limestone” of the Alps) and in shallow-water carbonates of the northwestern Tethys. Some of them occur rarely in Anisian or in Norian-Rhaetian reefs.  相似文献   
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Primary amenorrhea is one of the common reproductive disorder affecting females. It leads to the absence of menarche in the reproductive age group in females and/or complete absence of reproductive organs. There are many causes which lead to PA, including genetic aberrations which are the leading factors.  相似文献   
77.
Aiming to get useful steroidal alkaloids by tissue culture of Solanum laciniatum Ait., indefinitely growing callus tissue was prepared from the mother plant. Some nutritional requirements for the growth of the callus tissue were studied. By examining steroidal compounds in callus culture, cholesterol, stigmasterol, β-sitosterol, lanosterol, squalene, diosgenin and a new steroidal alkaloid were found to be formed in the callus culture. The new steroidal alkaloid was found to be solasodine derivative containing rhamnose and other unidentified sugars.  相似文献   
78.
The enantioselective hydrolysis of (R,S)-3-acetoxymethyl-7,8-difluoro-2,3-dihydro-4H-[1,4]benzoxazine (I) with enzymes was investigated. Optically active I and its hydrolyzate, 7,8-difluoro-2,3-dihydro-3-hydroxymethyl-4H-[1,4]benzoxazine (II), are the intermediates for preparing optically active ofloxacins, whose racemate is known to be an excellent antibacterial agent. Lipoprotein lipase from Pseudomonas fluorescens (LPL Amano 3) was found to predominantly hydrolyze (S)-I, giving (R)-I in 54% e.e. and (R)-II in 44% e.e. On the other hand, lipase from Candida cylindracea was found to predominantly hydrolyze (R)-I, giving (S)-I in 24% e.e. and (S)-II in 20% e.e. Since, the optical purities of I and II thus obtained were not particularly high, these optically active I and II were converted into 3-acetoxymethyl-7,8-difluoro-2,3-dihydro-4-(3,5-dinitrobenzoyl)-4H-[1,4]benzoxazine (IV). After recrystallizing IV from ethyl acetate-hexane, (S)- and (R)-II were obtained with high enantiomeric excess by removing the crystallized racemic IV and subsequently hydrolyzing the resulting optically active IV with alkali. The reduction of II afforded 7,8-difluoro-2,3-dihydro-3-methyl-4H-[1,4]benzoxazine (III), for which the optical purity was estimated to be >96%e.e. by HPLC analysis. (R)- and (S)-ofloxacin were prepared from (R)- and (S)-III with retention of their configuration.  相似文献   
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80.
Some patients with idiopathic pulmonary fibrosis (IPF) do not have honeycombing on high-resolution computed tomography (HRCT) at their initial evaluation. The clinical course and sequential changes in HRCT findings in these patients are not fully understood. We reviewed the cases of 43 patients with IPF without honeycombing on initial HRCT from institutions throughout Japan. All patients were diagnosed with IPF based on a surgical lung biopsy. Multidisciplinary discussions were held five times between 2011 and 2014, to exclude alternative etiologies. We evaluated the sequential changes in HRCT findings in 30 patients with IPF. We classified these 30 patients into three groups based on their HRCT patterns and clarified the clinical characteristics and prognosis among the groups. The patterns of all 30 patients on initial HRCT corresponded to a possible usual interstitial pneumonia (UIP) pattern which was described in the 2011 International Statement. On long-term follow-up (71.0±38.7 standard deviation [SD] months), honeycombing was seen in 16 patients (53%, the HoneyCo group); traction bronchiectasis or cysts without honeycombing was observed in 12 patients (40%, the NoHoneyCo group), and two patients showed no interval change (7%, the NoChange group) on HRCT. The mean survival periods of the HoneyCo and NoHoneyCo groups were 67.1 and 61.2 months, respectively (p = 0.76). There are some patients with IPF whose conditions chronically progress without honeycombing on HRCT. The appearance of honeycombing on HRCT during the follow-up might not be related to prognosis.  相似文献   
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