27 research outputs found
Crowdfunding als innovative Start-Up Finanzierung: Auswertung der Online-Studie des Entrepreneurship Centers zur Beurteilung der Option Crowdfunding durch Start-Ups
Neben den klassischen Finanzierungsmodellen für Start-ups wie Kredite, Fördermittel und Angels-Investments hat sich die Finanzierung durch die Menge – die Crowd – mittlerweile durchgesetzt.
Start-ups können mit Hilfe dieser innovativen Finanzierungsart Kapital für ihr Unternehmen sammeln. In der Studie wird die Wahrnehmung der deutschen Start-ups bezüglich Crowdfunding analysiert und die Präferenzen der Gründer hinsichtlich verschiedener Optionen dargestellt.Crowd Funding has become an important innovative form of financing for young start-ups. Via internet based platforms the private investors are able to invest in start-ups. In this empirical analysis we show how German start-ups evaluate crowd funding and the different options related to it
Method for quantification of the myelin content using luxol fast blue staining in injured spinal cord of adult rats and whole body vibration as a possible method for enhancing (re)myelination
Introduction: Luxol fast blue (LFB) is a dye that binds stoichiometrically to myelin and allows quantification of the myelination in preparations from the CNS. Therefore, LFB`s can be used to evaluate the damage after spinal cord injury (SCI) and the effect of diverse treatment methods on remyelination in the injured spinal cord.Materials and methods: 37 female Wistar rats were subjected to a compressive SCI at a low-thoracic level (vertebra Th8). The animals were randomized to four groups treated daily with whole body vibration (WBV) starting 1, 7, 14 or 28 days after injury (WBV1, WBV7, WBV14, WBV28) that continued for 12-weeks. Four groups served as controls - rats euthanized in the first 2 weeks post SCI (subacute), untreated (Sham therapy), treated with passive flexion-extension (PFE) and intact animals. We measured the optical density (OD) of longitudinal spinal cord sections stained with LFB. The entire slice area and a region of interest spanning 2.5 mm on both sides of the compression site were evaluated. In a second step we applied an image mask to exclude the `empty` fields from the section (due to vessels, tears or damage vacuoles). Thus, the OD is evaluated once in the entire sectional plane and a second time only in the preserved tissues (correspondingly the preserved neural tissue bridging the compression (PNTB)). The two measurement modes allowed the calculation of different quantitative features of the LFB staining.Results: WBV groups showed different degree of remyelination compared to sham therapy. A trend for better (re)myelination in the PNTB was observed in the WBV14 group.Conclusion: Using LFB staining for analysis in SCI animal models is suitable for quantification of the myelination. The method allows an evaluation and comparison between the different groups and treatment options. WBV could enhance remyelination depending on the day it was initiated
Long-term therapy with botulinum toxin in facial synkinesis: Retrospective data analysis of data from 1998 to 2018
Objectives Treatment with botulinum toxin A (BoNT) is the therapy of choice for many patients with facial synkinesis. Repeated injections relieve hypertonicity and hyperkinesis of reinnervated mimic muscles. Aim of the study was to prove if the injection regime and dosage of BoNT change during long-time therapy. Design Retrospective analysis of patients ' data, who were treated for synkinesis with BoNT from 1998 to 2018. Setting Tertiary referral facial nerve centre. Participants Injection pattern of BoNT was based on clinical symptoms, observations of the specialist and on previous treatment pattern. Onabotulinumtoxin (OnaBoNT), Incobotulinumtoxin (IncoBoNT) and Abobotulinumtoxin (AboBoNT) were available for treatment. Patients consulted our department for following treatment as soon as the symptoms re-occurred. Main outcome measures Change in dosage and injection pattern, the time intervals between treatments over the entire therapy period. Results Seventy-three patients were repeatedly injected. The median number of treatments was 18, the median treatment interval was 3.0 months. During the initial treatment, orbicularis oculi and the mentalis muscles were the most frequently injected muscles (94%). During repeated treatment, the number of injected muscles increased significantly (P .05). Conclusions We observed significant change in treatment dose and injection pattern of BoNT in patients with facial synkinesis. These results provide an orientation in dose finding and injection regimen of BoNT in the long-term course of therapy
Effect of Pulsed and Continuous Ultrasound Therapy on the Degree of Collateral Axonal Branching at the Lesion Site, Polyinnervation of Motor End Plates, and Recovery of Motor Function after Facial Nerve Reconstruction
The aim of the present study is to test whether ultrasound therapy of muscles denervated by nerve injury would improve the quality of their reinnervation by reduction of the collateral axonal branching at the lesion site and poly-innervation degree at the neuromuscular junctions. After transection and suture of the buccal branch of the facial nerve, pulsed or continuous type of ultrasound therapy was applied to the paralyzed whisker pad muscles of rats in the course of 2 months. Instead of reduction, we found a significant increase in the collateral axonal branching after continuous ultrasound therapy when compared to the branching determined after pulsed or sham ultrasound therapy. Both types of ultrasound therapy also failed to reduce the proportion of polyinnervated end plates in the reinnervated facial muscles. Accordingly, continuous ultrasound therapy failed to restore any parameter of the motor performance of the vibrissal hairs. Application of pulsed ultrasound therapy promoted slight improvements of the functional parameters angular velocity and acceleration. The inhomogeneous structural and functional results achieved after both types of ultrasound therapy let us conclude that further studies are required to evaluate its effects on peripheral nerve regeneration. Anat Rec, 302:1314-1324, 2019. (c) 2019 Wiley Periodicals, Inc
Trigeminal Sensory Supply Is Essential for Motor Recovery after Facial Nerve Injury
Recovery of mimic function after facial nerve transection is poor. The successful regrowth of regenerating motor nerve fibers to reinnervate their targets is compromised by (i) poor axonal navigation and excessive collateral branching, (ii) abnormal exchange of nerve impulses between adjacent regrowing axons, namely axonal crosstalk, and (iii) insufficient synaptic input to the axotomized facial motoneurons. As a result, axotomized motoneurons become hyperexcitable but unable to discharge. We review our findings, which have addressed the poor return of mimic function after facial nerve injuries, by testing the hypothesized detrimental component, and we propose that intensifying the trigeminal sensory input to axotomized and electrophysiologically silent facial motoneurons improves the specificity of the reinnervation of appropriate targets. We compared behavioral, functional, and morphological parameters after single reconstructive surgery of the facial nerve (or its buccal branch) with those obtained after identical facial nerve surgery, but combined with direct or indirect stimulation of the ipsilateral infraorbital nerve. We found that both methods of trigeminal sensory stimulation, i.e., stimulation of the vibrissal hairs and manual stimulation of the whisker pad, were beneficial for the outcome through improvement of the quality of target reinnervation and recovery of vibrissal motor performance
Effect of surgically guided axonal regrowth into a 3-way-conduit (isogeneic trifurcated aorta) on functional recovery after facial-nerve reconstruction: Experimental study in rats
Background: The post-paralytic syndrome after facial nerve reconstruction has been attributed to (i) malfunctioning axonal guidance at the fascicular (branches) level, (ii) collateral branching of the transected axons at the lesion site, and (iii) intensive intramuscular terminal sprouting of regenerating axons which causes poly-innervation of the neuromuscular junctions (NMJ). Objective: The first two reasons were approached by an innovative technique which should provide the re-growing axons optimal conditions to elongate and selectively re-innervate their original muscle groups. Methods: The transected facial nerve trunk was inserted into a 3-way-conduit (from isogeneic rat abdominal aorta) which should guide the re-growing facial axons to the three main branches of the facial nerve (zygomatic, buccal and marginal mandibular). The effect of this method was tested also on hypoglossal axons after hypoglossal-facial anastomosis (HFA). Coaptational (classic) FFA (facial-facial anastomosis) and HFA served as controls. Results: When compared to their coaptation (classic) alternatives, both types of 3-way-conduit operations (FFA and HFA) promoted a trend for reduction in the collateral axonal branching (the proportion of double- or triple-labelled perikarya after retrograde tracing was slightly reduced). In contrast, poly-innervation of NMJ in the levator labii superioris muscle was increased and vibrissal (whisking) function was worsened. Conclusions: The use of 3-way-conduit provides no advantages to classic coaptation. Should the latter be impossible (too large interstump defects requiring too long interpositional nerve grafts), this type of reconstruction may be applied. (230 words
Prospective study on the Eustachian tube function during Frenzel maneuver in a hypobaric/hyperbaric pressure chamber
Introduction The Frenzel maneuver describes a technique for middle ear equalizing which is frequently used by apnea divers. It offers advantages compared to the most commonly used techniques such as the Valsalva or Toynbee maneuver. Until now, there is insufficient literature about the pressure dynamics and Eustachian tube (ET) function during the Frenzel maneuver. The aim of the present study was to characterize the ET function during the Frenzel maneuver. Materials and methods By means of an established standardized profile of compression and decompression in a hypo/hyperbaric pressure chamber, we examined different parameters such as the ET opening pressure (ETOP), ET opening duration (ETOD), and ET opening frequency (ETOF) in 11 experienced apnea divers and compared them to the parameters during the Valsalva and Toynbee maneuver. Results Standard values for ETOP, ETOD, and ETOF could be established for the Frenzel maneuver under standardized conditions in a hypo/hyperbaric pressure chamber. Compared to the Frenzel maneuver, ETOP was higher and ETOD longer (both p < 0.001) during the Valsalva maneuver whereas ETOP was lower and ETOD shorter (both p < 0.001) during the Toynbee maneuver. No difference regarding ETOF was observed between the Frenzel, Valsalva, and Toynbee maneuver. Discussion The Frenzel maneuver was shown to be at least as effective as the Valsalva maneuver concerning ET opening. We believe that knowledge of the Frenzel technique might facilitate the pressure equalization during diving and recommend implementation of an appropriate equalization training in apnea and scuba diving education