The impact of platelet-derived growth factor on closure of chronic tympanic membrane perforations: a randomized, double-blind, placebo-controlled study

Objective: Patients with tympanic membrane (TM) perforations often suffer from infections, and repetitive topical treatment may be required. These infections can be prevented by permanent closure of the TM perforation. Different surgical treatment options have been described, but non-invasive techniques may be preferred as they carry less risk than surgery. One non-invasive approach is to induce wound healing by application of growth factors. The effect and clinical utility of applying topical platelet derived growth factor (PDGF) for decrease of size and closure of chronic TM perforations is evaluated. Study design: Prospective, randomized, placebo controlled, double blind study Setting: Tertiary referral center. Patients: Twenty patients suffering with chronic suppurative otitis media without cholesteatoma for more than 3 months. Intervention: Topical treatment with PDGF or placebo applied weekly to the TM for 6 weeks. Main outcome measures: Success rate, defined as a reduction of perforation size of 50% or more to determine relative changes of the perforation size; effect of initial size and location of TM perforation on success rate, and air and bone conduction thresholds to determine air-bone gap (ABG) measured before treatment. Results: Randomization made matching pre-treatment perforation size of the two study groups impossible, and the initial rate perforation/TM was significantly smaller in the PDGF group. No difference between the two groups was found for perforation/TM < 10%. However, success rate did not differ significantly between the two groups (Power=0.8), and the effect of PDGF was found to be small (-2%, +-49% STD). Initial size and position of the TM perforation were not significant factors determining success. Mean ABG for the frequencies of 0.5, 1, 2, and 4 kHz was 22.5 dB. Conclusion: The topical application of PDGF as an office treatment for chronic otitis media is not a favourable alternative to surgery

99mTc-labelled PSMA ligand for radio-guided surgery in nodal metastatic prostate cancer: proof of principle

Purpose!#!Intraoperative identification of prostate cancer (PCa) lymph node (LN) metastases (LNM) detected by preoperative PSMA PET/CT may be facilitated by PSMA radio-guided surgery (RGS) with use of a γ-probe. Earlier we demonstrated excellent performance of the !##!Methods!#!Six patients with PCa with the suspicion of LNM on preoperative PSMA-PET/CT underwent [!##!Results!#!Separation of the tissue samples from 73 subregions resulted in 498 single samples. After final histopathology 356 LN, 160 LNM und 11 non-nodal PCa samples were identified. Median SUL of tumor-free samples (0.26) and samples with cancer (3.5) was significantly different (p &amp;lt; 0.0001). ROC analysis revealed an area under the curve (AUC) of 0.917 (95% CI 0.89-0.95). Using a SUL cutoff of 1.1, sensitivity, specificity, positive predictive value, and negative predictive values were 76.6%, 94.4%, 89.4% and 86.9%.!##!Conclusion!#!Ex situ analysis of

Effects of system parameters and damping on an optimal vibraiton-based energy harvester

The authors present a comprehensive study of the effects of damping and electromechanicalcoupling on the power optimality of a vibration-based energy harvester. The harvesterunder consideration utilizes a piezoceramic element operating in the {33} mode to scavengemechanical energy emanating from a sinusoidal-base excitation. Under typical operatingconditions, the piezoceramic element is subjected to small strains and low electric fields,which allows for the adaptation of the linear small-signal constitutive law to model itsbehavior. To optimize the harvested power, previous researches neglected the role of mechanicaldamping. This lead to results suggesting that the optimal-harvesting frequenciesare not effected by mechanical damping. However, in this paper, exact expressions forthe optimal frequency ratios that account for damping are derived. The results show thatmechanical damping affects the optimal frequency ratios and optimal harvested power qualitativelyand quantitatively. The effects of the electromechanical coupling coefficient is alsoexplored. It is observed that there is an optimal value of the coupling coefficient beyondwhich the harvested power decreases. This result breaks the taboo suggesting that largerelectromechanical coupling culminates in more efficient energy harvesting devices. Additionally,it is shown that at the optimal frequencies, and optimal load resistance, increasingthe electromechanical coupling saturates the harvested powe