Bibliothek

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 58 (1991), S. 1656-1658 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Vacuum scanning tunneling microscopy has been used to investigate the hydrogen-terminated Si(111) surfaces obtained upon dissolution of the native oxide in HF and NH4F solutions. Whereas etching in aqueous HF acid produces an atomically rough surface, comparable treatment in NH4F results in atomically flat surfaces. These atomically flat surfaces are extremely well ordered and exhibit terraces which extend thousands of angstroms.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    [s.l.] : Nature Publishing Group
    Nature 197 (1963), S. 452-454 
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] IN normal mouse haematopoietic tissue, there is a class of cells which, on being transplanted into heavily irradiated mice, can proliferate and form macroscopic colonies. In the spleen, the colonies formed in this manner are discrete and easy to count1"2. Microscopically, each colony appears as a ...
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    ISSN: 1434-0879
    Schlagwort(e): Key words Nitric oxide metabolites ; Erectile dysfunction ; Griess reaction ; Gas chromatography ; Mass spectrometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Recent research implicated that the relaxation of cavernous arterial and trabecular smooth muscle – the crucial event in penile erection – is initiated by the release of nitric oxide (NO) from nerve terminals within the cavernous tissue as well as from the endothelia that line the lacunar spaces and the intima of penile arteries. The present study was undertaken to determine whether plasma levels of the NO metabolites nitrate (NO− 3) and nitrite (NO− 2) in the systemic and cavernous blood of male subjects change during different penile conditions, and whether there is a difference in the NO− 3 and NO− 2 levels of normal males and patients with erectile dysfunction (ED). Twenty-four potent adult male volunteers and 15 patients with ED were exposed to visual and tactile erotic stimuli in order to elicit penile tumescence and, in the group of healthy volunteers, rigidity. Whole blood was aspirated from the corpus cavernosum and the cubital vein, and NO− 3 and NO− 2 levels were determined in plasma aliquots by means of the Griess reaction and a method combining gas chromatography and mass spectrometry (GC-MS). The mean systemic and cavernous plasma NO3 −/NO2 − level in blood samples obtained from the healthy volunteers was 25–31 μM when determined by means of the Griess reaction and 37–41 μM when measured by GC-MS. Both approaches revealed that NO3 −/NO2 − levels in the peripheral and cavernous blood do not change appreciably during developing erection, rigidity and detumescence. Moreover, no significant differences were found between NO3 −/NO2 − plasma levels in the systemic and cavernous blood samples taken from the normal subjects and patients during penile flaccidity, tumescence and detumescence. Our results may reflect the fact that NO metabolism in the corpora cavernosa in the phases of penile tumescence and rigidity may account for only a minor fraction of local levels of NO3 − and NO2 −, which may also derive from exogenous sources. Moreover, the basal levels of NO metabolites in the blood flushing the lacunar spaces of the cavernous body in the state of developing erection could conceal any release of NO that may occur within the penile tissue. Thus, we conclude that the quantification of NO metabolites by means of advanced detection methods, such as GC-MS, is of no use in the workup of ED.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    ISSN: 1434-0879
    Schlagwort(e): Ureter ; Nitric oxide ; Smooth muscle physiology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract There is ample evidence that nitric oxide (NO) is an important neurotransmitter in many tissues of the urogenital tract. The aim of the present study was to examine the possible role of NO in ureteral relaxation. Human ureteral rings were mounted in organ bath chambers and precontracted with KCl. Increasing doses of the NO donor linsidomine (SIN-1) were added with and without prior blockade of the NO/cGMP pathway by methylene blue and protein kinase (PK) inhibitors Rp-8-pCPT-cGMPS and Rp-8-CPT-cAMPS. Electrical field stimulation (EFS) was done before and after incubation with L-NOARD (N G-nitro-L-arginine) and TTX (tetratodoxin). For detection of neuronal NO synthase (NOS), ureters were stained immunohistochemically. Ureteral strips were dose dependently relaxed by SIN-1; preincubation with methylene blue and protein kinase G inhibitor significantly reduced the SIN-1-induced relaxations. No effects of L-NOARG and TTX on EFS-induced tone alterations were found. NOS-positive neuronal axons and nerve-ending-like structures were found in the muscular layers. Our in vitro findings suggest that ureteral relaxation may involve the NO pathway.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    ISSN: 1433-8726
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Cardiodilatin/atrial natriuretic peptide (CDD/ANP) is a hormone system of great clinical importance. The prohormone CDD/ANP-1-126 is a peptide synthesized in the heart and cleaved during exocytosis into the circulating form CDD/ANP-99-126. Urodilatin (CDD/ANP-95-126) is a homologue natriuretic peptide that differs from CDD/ANP-99-126 by four amino acids. Whereas CDD/ANP-99-126 circulates in blood plasma and is not excreted into the urine, urodilatin is detected only in urine. Urodilatin exerts its renal effects in a paracrine fashion. After its secretion from cells in the distal tubule, it interacts with luminally located receptors in the collecting duct, resulting in increased diuresis and natriuresis. Results suggest that urodilatin plays an important role in the physiologic regulation of fluid balance and sodium homeostasis. Pharmacology studies reveal significant differences when urodilatin and CDD/ANP-99-126 are given intravenously, showing that stronger diuresis and natriuresis are induced by urodilatin as compared with those induced by CDD/ANP-99-126. Clinical studies indicate the prophylactic and therapeutic effect of urodilatin in patients suffering from acute renal failure following heart and liver transplantation. A significant reduction in requirements for hemodialysis/hemofiltration can be achieved using urodilatin. Postobstructive diuresis and natriuresis is probably due to a defective urinary concentrating mechanism and is usually resistant to treatment with antidiuretic hormone. The distal tubule and collecting duct have often been considered to be the site of altered sodium and water excretion following relief of obstruction. Since circulating CDD/ANP-99-126 levels are markedly elevated during obstruction and decrease upon relief of the obstruction, natriuretic peptides may play an important role in this clinical feature. On the basis of recent findings attributing an important role in sodium homeostasis to urodilatin in contrast to CDD/ANP-99-126, future studies have to clarify whether urodilatin, not CDD/ANP-99-126, might be responsible for the altered renal sodium excretion observed in postobstructive diuresis.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Hyperfine interactions 1 (1975), S. 193-215 
    ISSN: 1572-9540
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract 57Co has been oriented in an iron foil at temperatures down to 12.7 moK. The57Co magnetic moment was measured by taking temperature-dependent57Co and60Co data, and the result was μ(57Co)=4.733±0.023 n.m. The mixing ratios, δ=E2/M1, of the intense 122 keV γ-ray as well as of the weak57Fe γ-rays, resulting from the decay of the 707 keV level, were measured. We obtained δ (122)=0.1195±0.0010, −0.186〈δ (230) 〈0.072 or −6.99〈δ (230)〈−2.38, δ (352)=0.038±0.010 or 3.35±0.12, δ (367)= =−0.047±0.025 or −1.56±0.09, δ (340)=0.0827±0.0051, δ (570)=0.0974±0.0081 and δ (692)=−0.4654±0.0082.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    ISSN: 1572-9540
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Hyperfine interactions 4 (1978), S. 930-941 
    ISSN: 1572-9540
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Der Urologe 36 (1997), S. 351-355 
    ISSN: 1433-0563
    Schlagwort(e): Key words Impotence • Veins • Penile venous surgery • Penile erection ; Schlüsselwörter Impotenz • Penile Venenchirurgie • Prognosefaktoren
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung In den letzten Jahren wurde vermehrt über schlechtere Langzeiterfolge der Penisvenenchirurgie bei venösem Leck berichtet. Dies veranlaßte uns, unser Patientenkollektiv von 126 Patienten, die zwischen 1987 und 1996 einer dorsalen Penisvenenligatur unterzogen wurden, im Rahmen einer erneuten klinischen Visite oder durch ein standardisiertes Telefoninterview bzw. einen Fragebogen im Langzeit-Follow-up zu evaluieren. Den klinischen Ausgang teilten wir in folgende 3 Gruppen ein: volle spontane Erektion, postoperatives Ansprechen auf Schwellkörperautoinjektionstherapie (SKAT) und keine Veränderung der Erektionsfähigkeit postoperativ. Der Kurzzeiterfolg nach 1–3 Monaten betrug auf diese Gruppen bezogen 31 (24,6 %), 25 (19,8 %) und 70 (55,6 %) Patienten. Nach einer Langzeitbeobachtung von 6–76 Monaten (Mittelwert 33 ± 19,6) verschlechterten sich diese Werte auf 14 (11,2 %), 24 (19 %) und 88 (69,8 %) Patienten. Eine erneute Verschlechterung eines anfänglichen Operationserfolges trat in 86 % der Fälle innerhalb des ersten postoperativen Jahres auf (p K 0,001). Als günstige Prognosefaktoren konnten wir ein präoperatives Bestehen der Erektionsstörung unter 7 Jahre, ein normales Corpus-cavernosum-Elektromyogramm (CC-EMG) und ein Maintenance-Flow unter 45 ml/min bestimmen. Waren alle drei Parameter gegeben, so stieg die Langzeiterfolgsrate (spontane Erektion plus SKAT-Responder) von 30 % im gesamten Patientengut auf 67 % bei diesem günstigen Patientenkollektiv (p K 0,001). Diese Studie zeigt, daß die Langzeiterfolge der DPVL bei nicht-selektionierten Patienten enttäuschend sind, eine Selektion der Patienten jedoch mit bestimmten Prognosefaktoren vorgenommen werden kann.
    Notizen: Summary Poor longterm success has been reported for penile vein ligation the last few years. Therefore, we decided to re-investigate our group of 147 patients who were operated on between 1987 and 1996. All patients showed a negative response to intracavernous injection therapy at the time of diagnosis and revealed a maintenance flow 〉 15 ml/min, as well as a pathological venous flow with pharmacocavernosometry or pharmacocavernosography. These patients underwent ligation of all superficial dorsal veins and resection of the deep dorsal vein of the penis. An up-to-date record of the success of the operation was kept either by a renewed clinical visit or by a standardized telephone interview or questionnaire. A total of 126 patients were available here for long-term follow-up. We divided the findings into three groups: complete spontaneous erection, postoperative response to cavernous auto-injection therapy and no changes in erectile competency postoperatively. The short-term success rate for these groups after 1–3 months was an outcome of 31 (24.6 %), 25 (19.8 %) and 70 (55.6 %) patients; 86 % of the cases whose results deteriorated after the initial operation success rate had this happen within the first postoperative year (p K 0.001). Favorable prognostic factors were preoperative erectile dysfunction of K 7 years, a normal CC-EMG and a maintenance flow of K 45 ml/min. If all three parameters were present, the long-term success rate (spontaneous erection plus response to intracavernous injection) of 30 % of all patients was found to rise to 67 % in this selected group of patients (p K 0.001). This study reveals that long-term success for unselected patients undergoing penile venous surgery is disappointing; however, careful selection of patients by certain prognostic factors can improve long-term results.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Der Urologe 37 (1998), S. 503-508 
    ISSN: 1433-0563
    Schlagwort(e): Key words Erectile dysfunction • Phosphodiesterase • Apomorphin • PGE1 ; Schlüsselwörter Erektile Dysfunktion • Medikamentöse Therapie • Phosphodiesterase • Apomorphin • Yohimbin • PGE1
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die medikamentöse Therapie der erektilen Dysfunktion umfaßt die orale sowie die lokale Applikation von Pharmaka. Die zum jetzigen Zeitpunkt einzige zugelassene orale Substanz mit nachgewiesener Effektivität ist Yohimbin, ein zentral wirksamer Alpharezeptorenblocker. Weitere orale Medikamente mit zentralem Angriffspunkt sind Trazodon und Apomorphin, wobei Apomorphin signifikant besser wirkte als Placebo. Sildenafil, ein Phosphodiesterase-Isoenzym-V-Inhibitor mit überwiegend peripherem Wirkmechanismus, zeigte ebenfalls ermutigende Ergebnisse in klinischen Studien. Zur lokalen Applikation stehen sowohl die intraurethrale (MUSE) als auch der intracavernöse Anwendungsweise zur Verfügung. Als verwendete Substanz hat zum jetzigen Zeitpunkt Prostaglandin E1 (Caverject) andere Pharmaka weitgehend verdrängt. Zur Zeit befinden sich mehrere erfolgversprechende Substanzen mit unterschiedlichstem Wirkansatz und verschiedenen Darreichungsformen in der Entwicklung als Therapeutikum bei erektiler Dysfunktion. Hierdurch wird eine signifikante Verbesserung der medikamentösen Behandlung dieser Erkrankung mit weitgehendem Eingehen auf individuelle Gegebenheiten und Wünsche möglich sein.
    Notizen: Summary Pharmacotherapy of erectile dysfunction comprises oral and local application of drugs. Today, Yohimbin is the only drug listed for this indication. Yohimbin acts via central alpha-receptor blockade and showed a significant effect in a recent double blind study compared to placebo. The centrally acting substances Apomorphin and Trazodone were also tested for their potential use with Apomorphin showing promising results. The orally active phosphodiesterase-V inhibitor Sildenafil acts predominantly on the peripheral side; broad clinical studies demonstrated a significant effect of the drugs compared to placebo. For local use, intraurethral (MUSE) and intracavernous applications are available with PGE1 being the drug the most widely used for the moment. Since many different drugs with various modes of action and different modes of application are being developped at the moment, future pharmacological treatments will allow a more refined approach towards an individually adapted regimen.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...