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
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 75 (1999), S. 4145-4147 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Effects of a NiO layer on the electrical properties of NiAu-based ohmic contacts for p-GaN were studied by depositing a p-type NiO layer on the p-GaN using a sputter-deposition technique. NiO layers doped with Li[NiO(Li)] had a p-type conduction with sheet resistivity of around 1 Ω cm after annealing at temperatures lower than 500 °C. A variety of the NiAu-based contacts with the NiO layers such as NiO/Au, NiO(Li)/Au, Ni/NiO(Li)/Au, Ni/Li2O/NiO/Au, and Ni/Li2O/Ni/NiO/Au contacts were prepared by depositing on the p-GaN, where a slash "/" indicates the deposition sequence. However, these contacts did not provide specific contact resistances (ρc) lower than that (ρc∼10−2 Ω cm2) of the conventional Ni/Au contacts prepared by annealing in N2 ambient. From the present results, it was believed that the p-NiO layer did not act as an intermediate semiconductor layer to reduce the Schottky barrier height at the p-GaN/Au interface. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1600-0595
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— The re-innervation process in the periodontal ligament of replanted canine teeth was examined by immunohistochemistry for protein gene product 9.5 (PGP 9.5), a general marker for neurons, and by electron microscopy. Within 1 week of replantation, the periodontal fibers had regenerated, filling the narrow spaces between the alveolar bone and the root surface around the cervical and apical regions. Near the root apex, however, no PGP 9.5-im-munopositive nerve fibers were found in the regenerated periodontal ligament except for those in the alveolar half of the ligament. At 2 weeks after replantation, many nerve fibers positive for PGP 9.5 had ascended the periodontal ligament from the thick nerve bundles located near the root apex. Fine nerve endings showing complicated ramification were also present in the apical region. By 3 or 4 weeks after replantation, the vascular network was regenerated and principal periodontal fibers were re-established throughout the entire length of the periodontal ligament. The extensively ramified PGP 9.5-immunopositive structures had increased in thickness and density and showed characteristic treelike profiles by 3 weeks. Electron microscopy confirmed that most of these structures were Ruffini-like endings, and demonstrated that such nerve terminals were almost regenerated by 4 weeks post-replantation. These results indicated that, in the periodontal ligament of replanted canine teeth, the regeneration of the nerve fibers including mechanosensory receptors first showed signs of regeneration by 2 weeks following tooth replantation and proceeded rapidly thereafter. Regeneration of the periodontal ligament including fiber architecture as well as vascular and neural elements was almost complete by 4 weeks after replantation.
    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
    Journal of oral rehabilitation 26 (1999), S. 0 
    ISSN: 1365-2842
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The authors attempted to clarify the primary factors affecting the timing of the initial electromyographic discharges in the jaw depressor muscles (EMG onset). The changes in EMG onset in the inferior head of the lateral pterygoid (Lpt) and the anterior belly of the digastric muscles (Dig) were measured by varying duration of the open–close movement or occlusal force during the open–close–clench cycle (OCC). EMG onset tended to precede the beginning of the opening movement during OCC. The duration of opening and closing phase and the duration of occluding phase showed no significant correlation with the time-lag between EMG onset and the beginning of the opening movement (onset time).The mean EMG activity of the masseter muscle (Mm), corresponding to the occlusal force, showed a highly significant correlation with the onset time. The maximal opening velocity was highly correlated with the mean EMG activity of the jaw depressors before jaw opening. In conclusion, it was found that occlusal force is a major factor in EMG onset in the jaw depressors. It is suggested that smooth opening needs tooth contact with some degree of occlusal force.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Abdominal imaging 22 (1997), S. 45 -46 
    ISSN: 1432-0509
    Keywords: Key words: Torsion—Greater omentum—Diagnosis—CT—MR.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. We report a case of torsion of the greater omentum, which occurred in a 39-year-old man with an adhesive inguinal hernia. Preoperative computed tomography and magnetic resonance (MR) imaging showed a characteristic whirling fatty mass occupying the middle and lower abdomen anteriorly. MR imaging also showed difference of intensities in the twisted omentum, suggesting the presence of the pathological conditions of edema or congestion.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-0509
    Keywords: Key words: Liver, neoplasms—Liver, metal—Magnetic resonance imaging—Hepatocellular carcinoma—Liver, signal intensity. [xm [fs99]
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Background: To elucidate the metallic factors contributing to the signal intensities of hepatocellular carcinoma (HCC) on T1-weighted magnetic resonance (MR) images and to determine whether or not changes in signal intensity contribute to the diagnosis of histological grading of HCC. Methods: In 35 patients immediately after surgery, the quantities of water, lipid, copper (Cu), iron (Fe), and manganese (Mn) were determined in HCCs and the surrounding hepatic parenchyma. The correlations among these findings, the histopathological findings, and the signal intensities of T1-weighted MR images were evaluated. Results: Among the 35 HCCs, 12 (34%) were of high intensity, 14 (40%) were isointense, and 9 (26%) were of low intensity on T1-weighted images versus the surrounding hepatic parenchyma. The paramagnetic ions, which contributed to the signal intensity patterns, were assumed to be Cu in HCCs (30.5 ± 52.9 μg/g ww), and Fe in the livers (106.2 ± 86.8 μg/g ww) and HCCs (87.7 ± 49.1 μg/g ww). In 12 HCCs with high intensity, one was grade I, eight were grade II, and three were grade III according to Edmondson-Steiner's histopathological classification. Conclusions: Signal intensity and signal intensity patterns alone cannot be signs of low-grade malignancy because of the Fe in livers and in HCCs.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Histochemistry and cell biology 107 (1997), S. 105-114 
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The distribution of serotonin-immunoreactive (5HT-IR) nerve cells and fibers was thoroughly investigated immunohistochemically in the rat stomach, duodenum, jejunum, ileum, and colon. The immunoreactivity of the 5HT neurons was compared between non-treated controls and animals treated with colchicine, colchicine plus 5-hydroxytryptophan (5HTP), colchicine plus pargyline, and reserpine. The intensity of immunoreactivity in nerve fibers as well as nerve cell bodies was enhanced mostly in colchicine plus pargyline treated animals, therefore these animals were used for an observation of precise localization of 5HT in the rat gastrointestinal (GI) tract. Immunoreactivity in the nerve cell bodies and fibers was completely abolished in the GI tract of reserpine treated animals. The pattern of localization and projection of 5HT-IR neurons was similar in all segments of the rat GI tract. 5HT-IR nerve cell bodies were located in the myenteric plexus and showed the distinctive features of Dogiel type I neurons. Prominent bundles of varicose fibers traversed the myenteric ganglia and some of them surrounded the cell bodies of immunopositive and immunonegative neurons. 5HT-IR nerve fibers were located in the submucous plexus, densely entwined about the submucosal blood vessels. Most characteristically, 5HT-IR nerve fibers invaded the lamina propria of mucosa where they underlay the crypt epithelium. In conclusion, the present study showed that 5HT-IR neurons located in the myenteric plexus projected fibers widely in the rat GI tract. The localization of fibers in the lamina propria of mucosa implies that this neuron may exert an important role in the epithelial function of the GI tract.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-0878
    Keywords: Key words Calbindin D28k ; Circumvallate papilla ; Taste buds ; Development ; Degeneration ; Regeneration ; Immunohistochemistry ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The distribution of calbindin D28k (CB)-like immunoreactivity (-LI) in the circumvallate papilla (CVP) was examined during development and regeneration following bilateral crush injury to the glossopharyngeal nerve in the rat. In the adult CVP, CB-like immunoreactive (-IR) nerve fibers were observed in the subgemmal region and some penetrated into the taste buds. CB-LI was also detected in the cytoplasm of the spindle-shaped gustatory cells in the lower half of the trench epithelium, which contained numerous synaptic vesicles and bundles of intermediate filaments. These CB-IR gustatory cells made synapse-like contacts with CB-IR nerve terminals. Some CB-IR nerve terminals made contacts with the gustatory cells negative for CB-LI. At least three developmental stages were defined with regard to the developmental changes in the distribution of CB-LI: (1) Stage I (embryonic day (E) 18–postnatal day (P)5): CB-IR nerve fibers appeared in the lamina propria just beneath the newly-formed CVP at E18, but the gustatory epithelium of the CVP contained no CB-IR structures. Taste buds with taste pores appeared at P1. (2) Stage II (P5–10): thin CB-IR nerve fibers began entering the trench epithelium, but no CB-IR cells were observed. (3) Stage III (P10–adult): in addition to the intragemmal and perigemmal CB-IR nerve fibers, very few CB-IR cells appeared in the taste buds around P10, and their numbers increased progressively. The changes in the distribution of taste buds and CB-LI following glossopharyngeal nerve injury were similar to those observed during development. On post-operative day (PO) 4, the taste buds and CB-IR cells decreased markedly in number. These CB-IR cells became round in shape, and the number of CB-IR nerve fibers decreased markedly. On PO8, both taste buds and CB-IR cells disappeared completely. The regenerated taste buds were first observed on PO12, increased rapidly in number by PO20, and increased slowly thereafter. CB-IR nerve fibers accumulated at the subgemmal region and began penetrating into the trench wall epithelium around PO16. CB-IR cells appeared between PO20 and PO24, and their numbers increased progressively and reached the normal level on PO40. The topographical localizations of the taste buds and CB-IR cells during development and regeneration were comparable to those of normal animals. The delay of the time courses for appearance of CB-IR nerve fibers and CB-IR cells compared to the appearance of taste buds during development and regeneration suggests that CB in the gustatory epithelium may participate in the survival of the taste bud cells rather than in the induction of the taste buds.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1432-0878
    Keywords: Key words Calbindin ; Hertwig’s epithelial root sheath ; Epithelial rest of Malassez ; Preodontoblast ; Periodontal fibroblast ; Immunohistochemistry ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The present study was undertaken to examine the localization of calbindin D28k (CB)-like immunoreactivity (-LI) during the root formation of the rat molar. In the adult rat, CB-LI was detected in some of the cells of the epithelial rest of Malassez at the bifurcational region and in certain cells between the root dentin and cementum at the apical region. These cells had indented nuclei and many tonofilaments, and cementocytes lacked CB-LI. Moreover, CB-LI was observed in the periodontal fibroblasts in the alveolar half of the apical region. During root formation, the cells in the Hertwig’s epithelial root sheath (HERS) lacked CB-LI, but most fragmented cells along the root surface began to express CB-LI when HERS was disrupted. Preodontoblasts and odontoblasts at the apical portion of the root also showed CB-LI. After the formation of cellular cementum, the CB-immunoreactive (-IR) cells were entrapped between the root dentin and cementum in the apical portion of the root. The number of CB-IR cells at the root surface decreased gradually, while that between the root dentin and cementum increased. The fibroblasts in the periodontal ligament began to express CB-LI after commencement of the occlusion, and the number and the staining intensity of CB-IR fibroblasts increased gradually with the passage of time. The present results suggest that CB may play an important role in the survival of the epithelial cells, in the cellular responses of periodontal fibroblasts against mechanical forces caused by the occlusion, and in the initial mineralization by the odontoblasts through the regulation of intracellular Ca2+ concentration.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1617-4623
    Keywords: Key wordsSaccharomyces cerevisiae ; Calpain ; Alkaline adaptation ; Sporulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Saccharomyces cerevisiae has only one putative gene (designated CPL1) for a cysteine protease with a protease domain similar to that of calpain. This gene product shows significant sequence similarity to PalBp, a fungal (Emericella nidulans) calpain-like protease that is responsible for adaptation under alkaline conditions, both in the protease domain and the domain following the protease domain. CPL1 disruptant strains show impaired growth at alkaline pH, but no obvious growth defects under acidic pH conditions. This phenotype is complemented by the wild-type CPL1 gene, and its protease activity is essential for complementation. Disruption of CPL1 also causes reduced sporulation efficiency and promotes the degradation of the transcription factor Rim101p, which is involved in the sporulation pathway and has been shown to accumulate in a C-terminally truncated, active form under alkaline conditions. Furthermore, expression of the C-terminally truncated Rim101p suppressed the alkaline sensitivity associated with CPL1 disruption. These results indicate that a calpain-like cysteine protease, Cpl1p, plays an important role in alkaline adaptation and sporulation processes, via regulation of the turnover and processing of the transcription factor Rim101p.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1573-6776
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Inhibition of thermolysin-catalyzed peptide synthesis of N-(benzyloxycarbonyl)-L-phenylalanyl-L-phenylalanine methylester (Z-Phe-Phe-OMe) in aqueous organic one-phase reaction system by water-miscible alcoholic organic solvents correlated with most of their physicochemical parameters. Structurally similar monoalcohols and diols, including water, showed a linear relationship between inhibition and physicochemical parameters. The structure of organic solvents thus plays the key role in determining enzymatic activity in reaction media containing organic solvents.
    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...