Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 66-70 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have investigated thin (In, Mn)As layer and (In, Mn)As quantum dots (with Mn mole fraction lower than 0.02) on GaAs(001) by fluorescence extended x-ray absorption fine structure (EXAFS) in order to study the local structures formed around the Mn atoms. The EXAFS analysis revealed that in a 10 nm thick (In, Mn)As layer, the In-site substitutional Mn and the NiAs-type MnAs coexisted, while the majority of the Mn atoms were substituted in the In-sites of InAs in (In, Mn)As quantum dots. It is considered that different growth modes for the thin layer and the quantum dots affect the local structures. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 50 (1988), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: Biphasic electrical field stimulation (0.5–5 Hz, 2 ms, 25 V, 3 min) and high K+ (10–30 mM, 5 min) released endogenous 3,4-dihydroxyphenylalanine (DOPA) from superfused rat striatal slices. Characteristics of the DOPA release were compared with those of 3,4-dihydroxyphenylethylamine (dopamine, DA). Electrical stimulation at 2 Hz evoked DOPA and DA over similar time courses, α-Methyl-p-tyrosine (0.2 mM) markedly reduced release of DOPA but not of DA. Maximal release (0.3 pmol) of DOPA was obtained at 2 Hz and at 15 mM K+. The impulse-evoked release of DOPA and DA was completely tetrodotoxin (0.3 μM) sensitive and Ca2+ dependent and the 15 mM K+-evoked release was also Ca2+ dependent. On l-[3,5-3H]tyrosine (1 μM) superfusion, high K+ (15 and 60 mM) released DOPA and DA together with concentration-dependent decreases in tyrosine 3-monooxygenase (EC 1.14.16.2) activity as indicated by [3H]H2O formation, followed by concentration-dependent increases after DOPA and DA release ended. These findings suggest that striatal DOPA is released by a Ca2+-dependent excitation-secretion coupling process similar to that involved in transmitter release.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    European journal of neuroscience 19 (2004), S. 0 
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The goal of this study was to compare the lateral inhibition and the habituation in the human auditory cortex, two important physiological effects during auditory processing that can be reliably measured by means of magnetoencephalography when recording auditory evoked fields. Applying 40-Hz amplitude-modulated stimuli allowed us to record simultaneously the slow transient evoked and the steady-state fields and thus to characterize the lateral inhibition and the habituation effect in primary and non-primary auditory cortical structures. The main finding of the study is that the lateral inhibition effect of non-primary auditory areas as measured on the major component of the slow transient auditory evoked field (N1) is significantly stronger than the corresponding habituation effect. By contrast, this effect was not observed for the 40-Hz steady-state fields, characterizing the activation of the primary auditory cortex in humans. The results might be interpreted as (i) evidence that the inhibition mediated by lateral connections is stronger than the habituation of excitatory neurons in the non-primary auditory cortex and (ii) the processing hierarchy in the human auditory cortex is demonstrated by the different behaviour of lateral inhibition and habituation in primary and non-primary auditory cortical structures.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    European journal of neuroscience 21 (2005), S. 0 
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The auditory evoked response is known to be changed by a preceding sound. In this study we investigated by means of magnetoencephalography how a preceding notch-filtered noise (NFN) with different bandwidths influences the human auditory evoked response elicited by the following test stimulus. We prepared white noise (WN) and four NFNs which were derived from WN by suppressing frequency regions around 1 kHz with 1/8-, 1/4-, 1/2- and 1-octave bandwidths. Stimulation for 3 s with this set of noises resulted in differences in responsiveness to a 1-kHz test tone presented 500 ms after the offset of the noises. The N1m response to the 1-kHz test tone stimulus was at a minimum when the preceding NFN had 1/4-octave stop-band frequencies as compared with 1/8-, 1/2- and 1-octave NFN and WN. This N1m decrement is explained by the imbalanced neural activities caused by habituation and lateral inhibition in the auditory system. The results contribute to understanding of the inhibitory system in the human auditory cortex.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background  Diabetic foot ulcers with exposed bones commonly result in amputation.Objectives  To determine whether exposure of bone marrow cells and subsequent grafting of epidermal sheets accelerates healing and reduces the need for amputation.Methods  Thirty-eight patients with chronic wounds caused by diabetes mellitus were enrolled in this study. Epidermal sheets obtained from suction blisters of each patient were grafted on to diabetic foot ulcers without exposed bones (n = 10) and were compared with the standard treatment of local wound care, debridement with a scalpel when indicated, bed rest and parenteral antibiotics (n = 8). In another group of patients, diabetic wounds with exposed bones were treated either with the standard procedure (n = 9) or with a newly developed experimental procedure (n = 11). In that new procedure, the affected bone was initially exposed by debridement with a scalpel, followed by partial excision with a bone scraper until fresh bleeding was observed from the exposed bone. The lesions were then immediately covered with an occlusive dressing, and finally the wound was covered with an epidermal graft of skin harvested from suction blisters. Patients in each group were matched with their counterparts by age, sex, wound size, wound infection and wound duration, to compare the time needed for total skin repair and rates of amputation.Results  Epidermal grafting significantly accelerated the healing of diabetic foot ulcers (P = 0·042) without exposed bones, with site-specific differentiation. The newly developed combination therapy resulted in the healing of all diabetic ulcers with exposed bones without the occurrence of osteomyelitis or the necessity for amputation (P 〈 0·0001).Conclusions  Our study indicates that early aggressive debridement of diabetic foot ulcers with exposed bones down to a bleeding vascularized base and then grafting epidermal sheets significantly improves healing and reduces the rate of amputation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background  The usefulness of bone marrow cells in accelerating wound healing has not been evaluated despite increasing evidence that bone marrow contains mesenchymal stem cells that have multipotentiality to differentiate into various types of cells after they enter the microenvironment of a specific tissue (niche).Objectives  To determine the effects of bone marrow cells and occlusive dressings in promoting wound healing in rats.Methods  We investigated by grafting, biopsy and immunohistochemistry whether various types of cells derived from green fluorescent protein (GFP)-transgenic rats would differentiate into wound component cells when administered topically on the wounds of rats. We also investigated whether topical application of bone marrow cells with an occlusive dressing would accelerate the healing of wounds with exposed bones, as measured by planimetry.Results  GFP-labelled bone marrow cells contained multipotent stem cells that sufficiently differentiated into wound myofibroblasts presenting with α-smooth muscle actin in granulation tissue. Other types of cells, including myocytes, adipocytes, peripheral blood cells from buffy coat and dermal fibroblasts, did not express myofibroblast characteristics morphologically or immunohistochemically. Application of bone marrow cells and an occlusive dressing accelerated the repair of wounds with exposed bones, compared with an occlusive dressing only or with the topical administration of bone marrow cells plus a semidry to dry dressing.Conclusions  Our study indicates that bone marrow cells accelerate the healing of wounds at least in part through their differentiation into wound myofibroblasts. Thus, treatment of wounds with bone marrow cells and a supportive occlusive dressing is effective in promoting the formation of healthy granulation tissue and also for the preparation of an ideal wound bed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background  Wounds with exposed bones caused by rheumatic diseases commonly result in amputation despite progress in our understanding of wound-healing mechanisms.Objectives  To determine whether an experimental therapy of bone marrow exposure, an occlusive dressing and subsequent grafting of epidermal sheets accelerates healing and reduces the need for amputation in patients with rheumatic diseases.Methods  Fifteen patients, including those with rheumatoid arthritis or systemic sclerosis, who had wounds with exposed bones were treated either with the standard procedure, consisting of local wound care, debridement with a scalpel, bed rest and parenteral antibiotics (n = 8), or with a newly developed experimental procedure (n = 7). In that new procedure, the affected bone was initially exposed by debridement with a scalpel, followed by partial excision with a bone scraper until bleeding was observed from the exposed bone. The lesions were immediately covered with an occlusive dressing, and were eventually treated with epidermal grafts obtained from suction blisters.Results  A comparison with standard therapy demonstrated that the time needed for wound healing was similar, but that the newly developed combination therapy reduced the risk of amputation (P = 0·020). No skin ulcers or erosions were observed for at least 1 year in five of seven patients (72%) due to the adoption of stable palmoplantar-type characteristics in grafts derived from the trunk epidermis.Conclusions  Our study indicates that exposure of bone marrow cells plus an occlusive dressing accelerates the healing of skin ulcers at least partly through the preparation of a healthy well-granulated wound bed and that subsequent epidermal grafting achieves site-specific differentiation through epithelial–mesenchymal interactions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 335 (1987), S. 274-277 
    ISSN: 1432-1912
    Keywords: Alpha1 adrenoceptors ; Alpha2 adrenoceptors ; Arterial pressure ; Nucleus tractus solitarii
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cardiovascular effects of selective alpha1 and alpha2 agonists and antagonists injected into the nucleus tractus solitarii (NTS) were studied in urethane-anesthetized rats. Methoxamine (0.3–3 μg) injected bilaterally into the NTS caused a dose-dependent increase in blood pressure and heart rate. Phenylephrine (6 μg) and an imidazolidine derivative St 587 (3 μg) similarly injected also produced an increase in blood pressure, whereas a-methylnoradrenaline and an azepine derivative B-HT 920 (1 and 3 μg) caused a decrease in blood pressure and heart rate. The pressor response to methoxamine (1 μg) was markedly inhibited by prazosin (0.3 pg) injected into the same sites or hexamethionum (25 mg/kg, i. v.). Prazosin (0.3 μg) alone injected bilaterally into the NTS did not affect the blood pressure, while yohimbine (0.1 μg) similarly injected increased the pressure. These results suggest that in the rat NTS there exist alpha1 adrenoceptors responsible for an increase in arterial pressure. The NTS alpha2 adrenoceptors seem to be involved in the tonic regulation of arterial pressure.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Solid state phenomena Vol. 78-79 (Apr. 2001), p. 367-376 
    ISSN: 1662-9779
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 99 (2000), S. 263-270 
    ISSN: 1432-0533
    Keywords: Key words Pituitary adenomas ; Hormonal ¶antigenicity ; Immunoelectron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Ultrastructurally, the antigenicity of major pituitary hormones in secretory granules was quantitatively investigated in five growth hormone (GH)-secreting adenomas, five prolactin (PRL)-secreting adenomas and eight clinically non-functioning (CN-F) adenomas. Sparsely granulated cells with a few or several small secretory granules (60–100 nm) exhibiting little or only weak antigenicity of various biochemically unrelated hormones were commonly observed in CN-F adenomas and occasionally in GH- and PRL-secreting adenomas. GH- or PRL-secreting adenomas consisted of many densely granulated cells with medium-sized (200–250 nm) or large (over 250 nm) secretory granules and a few or several sparsely granulated cells with small secretory granules. The densely granulated cells showed intense GH or PRL antigenicity and slight to moderate antigenicity for other hormones in large secretory granules and little or only weak antigenicity for various hormones including GH or PRL in small secretory granules. Their secretory granules larger than 160 nm or 140 nm significantly exhibited intense GH or PRL antigenicity (Fisher’s exact test; P 〈 0.05 and 〈 0.01, respectively). Two CN-F adenomas showed sparsely and densely granulated cells as well as intermediate cells. The densely granulated cells closely resembled GH-secreting cells. The intermediate cells simultaneously included small and medium-sized or large secretory granules exhibiting little/slight and intense GH-antigenicity, respectively. This study indicates that sparsely granulated cells of different categories showing slight antigenicity for various hormones, antigenically share the same origin, and that their hormonality, single or multiple, may be selectively activated in the developmental course of secretory granules.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...