Influence of spray drying parameters on the formation of β-phase poly(vinylidene fluoride)

A simple one-step spraying method to produce poly(vinylidene fluoride) (PVDF) in the desired conformation is presented. The content of the piezoelectric β-phase is measured at different spray drying conditions and during electrospray. The influence of a strong electrical field and charges on the droplet are investigated separately from the electrospray setup with a pneumatic atomizer. For this purpose, the electric field is integrated into a pneumatic atomization process by a plate capacitor and the charge of the droplets by corona discharge. To investigate the drying properties, the drying temperature and the flow rate of dry air are examined. The presented process offers the possibility to deposit PVDF films or to produce PVDF powders, in their piezoelectric β- and γ-phases or in the nonpolar α-phase

Time trends in the epidemiology of renal transplant patients with type 1 diabetes mellitus over the last four decades

Background. Diabetes mellitus (DM) type 1 is an important contributor to end-stage renal disease (ESRD) among younger transplant recipients. However, little is known about the changes in epidemiological characteristics of this population. Especially, time to reach ESRD may have changed in type 1 diabetic patients referred for transplantation, resulting in higher age at time of grafting. Such time trends may allow anticipating future developments regarding the demand for organ replacement in this patient group. Methods. We retrospectively analysed 173 patients with type 1 DM undergoing renal transplantation at our institution, stratified into four groups according to year of reaching ESRD (A = 1973-1983, B = 1984-1990, C = 1991-1995 and D = 1996-2002). For each group we determined age at diagnosis of DM, age at time of reaching ESRD and age at time of transplantation. From these data, the interval from diagnosis of DM to ESRD and from ESRD to transplantation was calculated. The results were analysed in relation to gender, year of and age at onset of diabetes. Results. Patients reaching ESRD in more recent years (group D) tended to be both younger at diagnosis of DM and older when reaching ESRD, resulting in higher mean age at transplantation (35.0, 37.5, 39.6 and 41.0 years in groups A, B, C and D, respectively). Accordingly, median duration to ESRD has significantly been prolonged over the last five decades in patients with type 1 DM undergoing renal transplantation (group A: 21.0, B: 20.7, C: 22.3 and D: 28.5 years; P<0.0001), this finding being more pronounced in female patients. Conclusions. The results of our analysis are compatible with a change in epidemiology in patients undergoing kidney transplantation. Older age at time of reaching ESRD may impact significantly on the demand for renal grafts, as patients are already clearly older nowadays when being transplanted. From our data it cannot be concluded whether this development is due to a change in the progression of diabetic nephropathy or may simply reflect a change in the selection of type 1 diabetic patients referred for transplantatio

Synaptotagmin-7 Is an Asynchronous Calcium Sensor for Synaptic Transmission in Neurons Expressing SNAP-23

Synchronization of neurotransmitter release with the presynaptic action potential is essential for maintaining fidelity of information transfer in the central nervous system. However, synchronous release is frequently accompanied by an asynchronous release component that builds up during repetitive stimulation, and can even play a dominant role in some synapses. Here, we show that substitution of SNAP-23 for SNAP-25 in mouse autaptic glutamatergic hippocampal neurons results in asynchronous release and a higher frequency of spontaneous release events (mEPSCs). Use of neurons from double-knock-out (SNAP-25, synaptotagmin-7) mice in combination with viral transduction showed that SNAP-23-driven release is triggered by endogenous synaptotagmin-7. In the absence of synaptotagmin-7 release became even more asynchronous, and the spontaneous release rate increased even more, indicating that synaptotagmin-7 acts to synchronize release and suppress spontaneous release. However, compared to synaptotagmin-1, synaptotagmin-7 is a both leaky and asynchronous calcium sensor. In the presence of SNAP-25, consequences of the elimination of synaptotagmin-7 were small or absent, indicating that the protein pairs SNAP-25/synaptotagmin-1 and SNAP-23/synaptotagmin-7 might act as mutually exclusive calcium sensors. Expression of fusion proteins between pHluorin (pH-sensitive GFP) and synaptotagmin-1 or -7 showed that vesicles that fuse using the SNAP-23/synaptotagmin-7 combination contained synaptotagmin-1, while synaptotagmin-7 barely displayed activity-dependent trafficking between vesicle and plasma membrane, implying that it acts as a plasma membrane calcium sensor. Overall, these findings support the idea of alternative syt∶SNARE combinations driving release with different kinetics and fidelity

Tissue-engineered vascular graft remodeling in a growing lamb model: expression of matrix metalloproteinases

OBJECTIVES We have previously demonstrated the functionality and growth of autologous, living, tissue-engineered vascular grafts (TEVGs) in long-term animal studies. These grafts showed substantial in vivo tissue remodeling and approximation to native arterial wall characteristics. Based on this, in vitro and in vivo matrix metalloproteinase (MMP) activity of TEVGs is investigated as a key marker of matrix remodeling. METHODS TEVGs fabricated from biodegradable scaffolds (polyglycolic-acid/poly-4-hydroxybutyrate, PGA/P4HB) seeded with autologous vascular cells were cultured in static and dynamic in vitro conditions. Thereafter, TEVGs were implanted as pulmonary artery replacements in lambs and followed up for 2 years. Gelatin gel zymography to detect MMP-2 and -9 was performed and collagen content quantified (n=5). Latent (pro) and active MMP-2 and -9 were detected. RESULTS Comparable levels of active MMP-9 and pro-MMP-2 were detected in static and dynamic culture. Higher levels of active MMP-2 were detected in dynamic cultures. Expression of MMP-2 and -9 was minimal in native grafts but was increased in implanted TEVG. Pro-MMP-9 was expressed 20 weeks post implantation and persisted up to 80 weeks post implantation. Collagen content in vitro was increased in dynamically conditioned TEVG as compared with static constructs and was increased in vivo compared with the corresponding native pulmonary artery. CONCLUSIONS MMPs are up-regulated in vitro by dynamic culture conditions and could contribute to increased matrix remodeling, native analogous tissue formation and functional growth of TEVGs in vivo. Monitoring of MMP activity, for example, by molecular imaging techniques, may enable the non-invasive assessment of functional tissue quality in future clinical tissue-engineering application

Replacing gas boilers with heat pumps is the fastest way to cut German gas consumption

The supply security of fossil gas has been disrupted by the Russo-Ukrainian War. Decisions to relocate the production and transport of gas have become so urgent that new long-term contracts are imminent that undermine the Paris Climate Agreement. Here, we simulate how quickly the addition of renewable electricity and the installation of heat pumps can substitute enough gas to reduce supply risk, while taking a decisive step towards meeting the Paris Agreement. Our bottom-up modelling, using Germany as an example, shows technical pathways on how installing heat pumps is one of the fastest ways to reduce gas consumption, in addition to reducing the load hours of gas-fired power plants. With targeted efforts, maximally 60% of gas from the Russian Federation can be substituted by 2025 with heat pumps and grid expansions, and enough electricity will remain available that the phase-out of coal and the entry into e-mobility will still be practicable

Pathogenicity of Highly Pathogenic Avian Influenza Virus (H5N1) in Adult Mute Swans

Adult, healthy mute swans were experimentally infected with highly pathogenic avian influenza virus A/Cygnus cygnus/Germany/R65/2006 subtype H5N1. Immunologically naive birds died, whereas animals with preexisting, naturally acquired avian influenza virus–specific antibodies became infected asymptomatically and shed virus. Adult mute swans are highly susceptible, excrete virus, and can be clinically protected by preexposure immunity

Neurofilament Light Chain: Blood Biomarker of Neonatal Neuronal Injury

Background: Neurofilament light chain (NfL) is a highly promising biomarker of neuroaxonal injury that has mainly been studied in adult neurodegenerative disease. Its involvement in neonatal disease remains largely unknown. Our aim was to establish NfL plasma concentrations in preterm and term infants in the first week of life.Methods: Plasma NfL was measured by single molecule array immunoassay in two neonatal cohorts: cohort 1 contained 203 term and preterm infants, median gestational age (GA) 37.9 weeks (interquartile range [IQR] 31.9–39.4), in whom venous and arterial umbilical cord blood was sampled at birth and venous blood at day of life (DOL) 3; cohort 2 contained 98 preterm infants, median GA 29.3 weeks (IQR 26.9–30.6), in whom venous blood was sampled at DOL 7.Results: Median NfL concentrations in venous blood increased significantly from birth (18.2 pg/mL [IQR 12.8–30.8, cohort 1]) to DOL 3 (50.9 pg/mL [41.3–100, cohort 1]) and DOL 7 (126 pg/mL [78.8–225, cohort 2]) (p &lt; 0.001). In both cohorts NfL correlated inversely with birth weight (BW, Spearman's rho −0.403, p &lt; 0.001, cohort 1; R −0.525, p &lt; 0.001, cohort 2) and GA (R −0.271, p &lt; 0.001, cohort 1; R −0.487, p &lt; 0.001, cohort 2). Additional significant correlations were found for maternal age at delivery, preeclampsia, delivery mode, 5-min Apgar, duration of oxygen supplementation, sepsis, and brain damage (intraventricular hemorrhage or periventricular leukomalacia). Multivariable logistic regression analysis identified the independent predictors of NfL in cohort 1 as BW (beta = −0.297, p = 0.003), delivery mode (beta = 0.237, p = 0.001) and preeclampsia (beta = 0.183, p = 0.022) and in cohort 2 as BW (beta = −0.385, p = 0.001) and brain damage (beta = 0.222, p = 0.015).Conclusion: Neonatal NfL levels correlate inversely with maturity and BW, increase during the first days of life, and relate to brain injury factors such as intraventricular hemorrhage and periventricular leukomalacia, and also to vaginal delivery

Over-the-scope clip (OTSC (R)) closure of a recto-acetabular fistula

A 25-year-old male Syrian refugee presented in our hospital with recurrent hip infections after having undergone hip arthroplasty abroad following destruction of his right hip joint by shell splinters in the Syrian civil war. The patient underwent hip arthroplasty revision with implantation of a cement spacer. CT-scan with rectal contrast media filling revealed a rectoacetabular fistula. Consecutively, the patient underwent ileostomy formation. The fistula was then successfully closed by endoscopic over-the-scope clipping (OTSC (R)). Fistulas between intestines and joints rarely develop and in the few cases published mostly extensive abdominal rescue surgery has been performed. Here, we present a case of a traumatic rectoacetabular fistula that was successfully closed by OTSC. This innovative method could represent a safe and suitable option to effectively close fistulas between joints and intestines thereby avoiding extensive rescue surgery with bowel resection or permanent ostomy

Experimental Infection and Natural Contact Exposure of Dogs with Avian Influenza Virus (H5N1)

Experiments that exposed influenza virus (H5N1)–infected cats to susceptible dogs did not result in intraspecies or interspecies transmission. Infected dogs showed increased body temperatures, viral RNA in pharyngeal swabs, and seroconversion but not fatal disease

Magnetostructural coupling in RFeO3 (R = Nd, Tb, Eu and Gd)

We investigate the interplay of magnetization and lattice vibrations in rare-earth orthoferrites RFeO3, with a specific focus on non-symmetry-breaking anomalies. To do so, we study the magnetization, magnon excitations and lattice dynamics as a function of temperature in NdFeO3, TbFeO3, EuFeO3 and GdFeO3. The magnetization shows distinct temperature anomalous behavior for all investigated rare-earth orthoferrites, even in the compounds with no phase transitions occurring at those temperatures. Through spin-phonon coupling, these magnetic changes are mirrored by the FeO6 rotation mode for all the studied RFeO3, revealing a common magnetostructural effect associated with the octahedra rotations. The R3+ oscillation modes evidence a Fe3+/R3+ spins cross-talk for the NdFeO3 and TbFeO3 cases. Our work sheds light into the common magnetostructural coupling in rare-earth orthoferrites, and the important role of magnetic anisotropy and spin-orbit coupling strength of the R-Fe interactions on the spin-reorientation transition at high temperatures