TY  - JOUR
A1  - Abbasi, Ali
A1  - Xu, Yaolin
A1  - Khezri, Ramin
A1  - Etesami, Mohammad
A1  - Lin, C.
A1  - Kheawhom, Soorathep
A1  - Lu, Yan
T1  - Advances in characteristics improvement of polymeric membranes/separators for zinc-air batteries
JF  - Materials Today Sustainability
N2  - Zinc-air batteries (ZABs) are gaining popularity for a wide range of applications due to their high energy density, excellent safety, and environmental friendliness. A membrane/separator is a critical component of ZABs, with substantial implications for battery performance and stability, particularly in the case of a battery in solid state format, which has captured increased attention in recent years. In this review, recent advances as well as insight into the architecture of polymeric membrane/separators for ZABs including porous polymer separators (PPSs), gel polymer electrolytes (GPEs), solid polymer electrolytes (SPEs) and anion exchange membranes (AEMs) are discussed. The paper puts forward strategies to enhance stability, ionic conductivity, ionic selectivity, electrolyte storage capacity and mechanical properties for each type of polymeric membrane. In addition, the remaining major obstacles as well as the most potential avenues for future research are examined in detail.
KW  - Ionic selectivity
KW  - Ionic conductivity
KW  - Gel polymer
KW  - Ion exchange
KW  - Porous
KW  - polymer
Y1  - 2022
U6  - https://doi.org/10.1016/j.mtsust.2022.100126
SN  - 2589-2347
VL  - 18
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Saalfrank, Peter
A1  - Klamroth, Tillmann
A1  - Huber, C.
A1  - Krause, Pascal
T1  - Laser-driven electron dynamics at interfaces
N2  - In this paper we present time-dependent, quantum-dynamical simulations of photoinduced processes at solid surfaces involving nonadiabatic transitions of electrons to and from short-lived intermediate excited states. In particular, two-photon photoemission (2PPE) spectra of naked metal surfaces and free-standing metal films are considered. One major problem in both cases is the presence of electron-electron scattering, which is treated here in various ways. The first way is to adopt an open-system density matrix approach, in which a single electron is weakly coupled to a "bath" of other electrons. The second approach is based on a many-electron Schrodinger equation, which is solved with the help of a time-dependent configuration interactions singles (TD-CIS) method
Y1  - 2005
SN  - 0021-2148
ER  - 
TY  - JOUR
A1  - Bronner, C.
A1  - Leyssner, F.
A1  - Stremlau, S.
A1  - Utecht, Manuel Martin
A1  - Saalfrank, Peter
A1  - Klamroth, Tillmann
A1  - Tegeder, P.
T1  - Electronic structure of a subnanometer wide bottom-up fabricated graphene nanoribbon: End states, band gap, and dispersion
JF  - Physical review : B, Condensed matter and materials physics
N2  - Angle-resolved two-photon photoemission and high-resolution electron energy loss spectroscopy are employed to derive the electronic structure of a subnanometer atomically precise quasi-one-dimensional graphene nanoribbon (GNR) on Au(111). We resolved occupied and unoccupied electronic bands including their dispersion and determined the band gap, which possesses an unexpectedly large value of 5.1 eV. Supported by density functional theory calculations for the idealized infinite polymer and finite size oligomers, an unoccupied nondispersive electronic state with an energetic position in the middle of the band gap of the GNR could be identified. This state resides at both ends of the ribbon (end state) and is only found in the finite sized systems, i.e., the oligomers.
Y1  - 2012
U6  - https://doi.org/10.1103/PhysRevB.86.085444
SN  - 1098-0121
VL  - 86
IS  - 8
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Schulz, Eike C.
A1  - Mehrabi, Pedram
A1  - Müller-Werkmeister, Henrike
A1  - Tellkamp, Friedjof
A1  - Jha, Ajay
A1  - Stuart, William
A1  - Persch, Elke
A1  - De Gasparo, Raoul
A1  - Diederich, François
A1  - Pai, Emil F.
A1  - Miller, R. J. Dwayne
T1  - The hit-and-return system enables efficient time-resolved serial synchrotron crystallography
JF  - Nature methods : techniques for life scientists and chemists
N2  - We present a ‘hit-and-return’ (HARE) method for time-resolved serial synchrotron crystallography with time resolution from milliseconds to seconds or longer. Timing delays are set mechanically, using the regular pattern in fixed-target crystallography chips and a translation stage system. Optical pump-probe experiments to capture intermediate structures of fluoroacetate dehalogenase binding to its ligand demonstrated that data can be collected at short (30 ms), medium (752 ms) and long (2,052 ms) intervals.
KW  - Biophysical chemistry
KW  - Enzymes
KW  - Molecular biophysics
KW  - X-ray crystallography
Y1  - 2018
U6  - https://doi.org/10.1038/s41592-018-0180-2
SN  - 1548-7091
SN  - 1548-7105
VL  - 15
IS  - 11
SP  - 901
EP  - 904
PB  - Nature Publishing Group (London)
CY  - London
ER  - 
TY  - JOUR
A1  - Ertan, Emelie
A1  - Savchenko, Viktoriia
A1  - Ignatova, Nina
A1  - Vaz da Cruz, Vinicius
A1  - Couto, Rafael C.
A1  - Eckert, Sebastian
A1  - Fondell, Mattis
A1  - Dantz, Marcus
A1  - Kennedy, Brian
A1  - Schmitt, Thorsten
A1  - Pietzsch, Annette
A1  - Föhlisch, Alexander
A1  - Odelius, Michael
A1  - Kimberg, Victor
T1  - Ultrafast dissociation features in RIXS spectra of the water molecule
JF  - Physical chemistry, chemical physics : a journal of European Chemical Societies
N2  - In this combined theoretical and experimental study we report on an analysis of the resonant inelastic X-ray scattering (RIXS) spectra of gas phase water via the lowest dissociative core-excited state |1s−1O4a11〉. We focus on the spectral feature near the dissociation limit of the electronic ground state. We show that the narrow atomic-like peak consists of the overlapping contribution from the RIXS channels back to the ground state and to the first valence excited state |1b−114a11〉 of the molecule. The spectral feature has signatures of ultrafast dissociation (UFD) in the core-excited state, as we show by means of ab initio calculations and time-dependent nuclear wave packet simulations. We show that the electronically elastic RIXS channel gives substantial contribution to the atomic-like resonance due to the strong bond length dependence of the magnitude and orientation of the transition dipole moment. By studying the RIXS for an excitation energy scan over the core-excited state resonance, we can understand and single out the molecular and atomic-like contributions in the decay to the lowest valence-excited state. Our study is complemented by a theoretical discussion of RIXS in the case of isotopically substituted water (HDO and D2O) where the nuclear dynamics is significantly affected by the heavier fragments' mass.
Y1  - 2018
U6  - https://doi.org/10.1039/c8cp01807c
SN  - 1463-9076
SN  - 1463-9084
VL  - 20
IS  - 21
SP  - 14384
EP  - 14397
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Yenesew, Abiy
A1  - Induli, M.
A1  - Derese, Solomon
A1  - Midiwo, Jacob O.
A1  - Heydenreich, Matthias
A1  - Peter, Martin G.
A1  - Akala, Hoseah M.
A1  - Wangui, Julia
A1  - Liyala, Pamela
A1  - Waters, Norman C.
T1  - Anti-plasmodial flavonoids from the stem bark of Erythrina abyssinica
N2  - The ethyl acetate extract of the stem bark of Erythrina abyssinica showed anti-plasmodial activity against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with IC50 values of 7.9 +/- 1.1 and 5.3 +/- 0.7 mug/ml, respectively. From this extract, a new chalcone, 2,3,4,4'-tetrahydroxy-5- prenylchalcone (trivial name 5-prenylbutein) and a new flavanone, 4',7-dihydroxy-3'-methoxy-5'- prenylflavanone (trivial name, 5-deoxyabyssinin II) along with known flavonoids have been isolated as the anti- plasmodial principles. The structures were determined on the basis of spectroscopic evidence. (C) 2004 Elsevier Ltd. All rights reserved
Y1  - 2004
SN  - 0031-9422
ER  - 
TY  - JOUR
A1  - Muiva-Mutisya, Lois M.
A1  - Atilaw, Yoseph
A1  - Heydenreich, Matthias
A1  - Koch, Andreas
A1  - Akala, Hoseah M.
A1  - Cheruiyot, Agnes C.
A1  - Brown, Matthew L.
A1  - Irungu, Beatrice
A1  - Okalebo, Faith A.
A1  - Derese, Solomon
A1  - Mutai, Charles
A1  - Yenesew, Abiy
T1  - Antiplasmodial prenylated flavanonols from Tephrosia subtriflora
JF  - Natural Product Research
N2  - The CH2Cl2/MeOH (1:1) extract of the aerial parts of Tephrosia subtriflora afforded a new flavanonol, named subtriflavanonol (1), along with the known flavanone spinoflavanone B, and the known flavanonols MS-II (2) and mundulinol. The structures were elucidated by the use of NMR spectroscopy and mass spectrometry. The absolute configuration of the flavanonols was determined based on quantum chemical ECD calculations. In the antiplasmodial assay, compound 2 showed the highest activity against chloroquine-sensitive Plasmodiumfalciparum reference clones (D6 and 3D7), artemisinin-sensitive isolate (F32-TEM) as well as field isolate (KSM 009) with IC50 values 1.4-4.6M without significant cytotoxicity against Vero and HEp2 cell lines (IC50>100M). The new compound (1) showed weak antiplasmodial activity, IC50 12.5-24.2M, but also showed selective anticancer activity against HEp2 cell line (CC50 16.9M). [GRAPHICS] .
KW  - Tephrosia subtriflora
KW  - Leguminosae
KW  - prenylated flavanonol
KW  - subtriflavanonol
KW  - antiplasmodial
KW  - cytotoxicity
Y1  - 2018
U6  - https://doi.org/10.1080/14786419.2017.1353510
SN  - 1478-6419
SN  - 1478-6427
VL  - 32
IS  - 12
SP  - 1407
EP  - 1414
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Kerubo, Leonidah Omosa
A1  - Midiwo, Jacob Ogweno
A1  - Derese, Solomon
A1  - Langat, Moses K.
A1  - Akala, Hoseah M.
A1  - Waters, Norman C.
A1  - Peter, Martin
A1  - Heydenreich, Matthias
T1  - Antiplasmodial activity of compounds from the surface exudates of senecio roseiflorus
JF  - Natural product communications : an international journal for communications and reviews
N2  - From the surface exudates of Senecio roseiflorus fourteen known methylated flavonoids and one phenol were isolated and characterized. The structures of these compounds were determined on the basis of their spectroscopic analysis. The surface exudate and the flavonoids isolated showed moderate to good antiplasmodial activity with 5,4'-dihydroxy-7-dimethoxyflavanone having the highest activity against chloroquine-sensitive (D6) and resistant (W2) strains of Plasmodium falciparum, with IC50 values of 3.2 +/- 0.8 and 4.4 +/- 0.01 mu g/mL respectively.
KW  - Senecio roseiflorus
KW  - Asteraceae
KW  - Surface exudates
KW  - Antiplasmodial activity
Y1  - 2013
SN  - 1934-578X
VL  - 8
IS  - 2
SP  - 175
EP  - 176
PB  - NPC
CY  - Westerville
ER  - 
TY  - JOUR
A1  - Andayi, Andrew W.
A1  - Yenesew, Abiy
A1  - Derese, Solomon
A1  - Midiwo, Jacob O.
A1  - Gitu, Peter M.
A1  - Jondiko, Ogoche J. I.
A1  - Akala, Hoseah M.
A1  - Liyala, Pamela
A1  - Wangui, Julia
A1  - Waters, Norman C.
A1  - Heydenreich, Matthias
A1  - Peter, Martin G.
T1  - Antiplasmodial flavonoids from Erythrina sacleuxii
N2  - The acetone extracts of the root bark and stem bark of Erythrina sacleuxii showed antiplasmodial activities against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum. Chromatographic separation of the acetone extract of the root bark afforded a new isoflavone, 7-hydroxy-4 -methoxy-3'- prenylisoflavone (trivial name 5-deoxy-3' - prenylbiochanin A) along with known isoflavonoids as the antiplasmodial principles. Flavonoids and isoflavonoids isolated from the stem bark of E. sucleuxii were also tested and showed antiplasmodial activities. The structures were determined on the basis of spectroscopic evidence
Y1  - 2006
UR  - http://www.thieme-connect.com/ejournals/toc/plantamedica
U6  - https://doi.org/10.1055/s-2005-873200
SN  - 0032-0943
ER  - 
TY  - GEN
A1  - Peter, Martin G.
A1  - Yenesew, Abiy
A1  - Twinomuhwezi, Hannington
A1  - Kabaru, Jacques M.
A1  - Akala, Hoseah M.
A1  - Kiremire, Bernard T.
A1  - Heydenreich, Matthias
A1  - Eyase, Fredrick
A1  - Waters, Norman C.
A1  - Walsh, Douglas S.
T1  - Antiplasmodial and larvicidal flavonoids from Derris trifoliata
N2  - From the dichloromethane-methanol (1:1) extract of the seed pods of Derris trifoliata, a new flavanone derivative (S)-lupinifolin 4´-methyl ether was isolated. In addition, the known flavonoids lupinifolin and rotenone were identified. The structures were determined on the basis of spectroscopic evidence. Lupinfolin showed moderate in vitro antiplasmodial activity against the D6 (chloroquine-sensitive) and W2 (chloroquineresistant) strains of Plasmodium falciparum. The different parts of this plant showed larvicidal activities against Aedes aegypti and rotenoids were identified as the active principles.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 121 
KW  - Derris trifoliata
KW  - Leguminosae
KW  - Flavanone
KW  - (S)-Lupinifolin 4´-methyl ether
KW  - Lupinifolin
Y1  - 2009
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44614
ER  - 
TY  - GEN
A1  - Peter, Martin G.
A1  - Muiva, Lois M.
A1  - Yenesew, Abiy
A1  - Derese, Solomon
A1  - Heydenreich, Matthias
A1  - Akala, Hoseah M.
A1  - Eyase, Fredrick
A1  - Waters, Norman C.
A1  - Mutai, Charles
A1  - Keriko, Joseph M.
A1  - Walsh, Douglas S.
T1  - Antiplasmodial β-hydroxydihydrochalcone from seedpods of Tephrosia elata
N2  - From the seedpods of Tephrosia elata, a new β-hydroxydihydrochalcone named (S)-elatadihydrochalcone was isolated. In addition, the known flavonoids obovatachalcone, obovatin, obovatin methyl ether and deguelin were identified. The structures were determined on the basis of spectroscopic evidence. The crude extract and the flavonoids obtained from the seedpods of this plant showed antiplasmodial activities. The literature NMR data on β-hydroxydihydrochalcones is reviewed and the identity of some of the compounds assigned β-hydroxydihydrochalcone skeleton is questioned.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 118 
KW  - Tephrosia elata
KW  - Leguminosae
KW  - Seedpods
KW  - (S)-Elatadihydrochalcone
KW  - β-Hydroxydihydrochalcone
Y1  - 2009
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44437
ER  - 
TY  - GEN
A1  - Troll, K.
A1  - Kulkarni, Amit
A1  - Wang, W.
A1  - Darko, C.
A1  - Koumba, A. M. Bivigou
A1  - Laschewsky, André
A1  - Müller-Buschbaum, Peter
A1  - Papadakis, Christine M.
T1  - The collapse transition of poly(styrene-b-(N-isopropyl acrylamide)) diblock copolymers in aqueous solution and in thin films
T2  - Colloid and polymer science : official journal of the Kolloid-Gesellschaft
Y1  - 2011
U6  - https://doi.org/10.1007/s00396-010-2344-1
SN  - 0303-402X
VL  - 289
IS  - 2
SP  - 227
EP  - 227
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Tadjoung Waffo, Armel Franklin
A1  - Yesildag, Cigdem
A1  - Caserta, Giorgio
A1  - Katz, Sagie
A1  - Zebger, Ingo
A1  - Lensen, Marga C.
A1  - Wollenberger, Ulla
A1  - Scheller, Frieder W.
A1  - Altintas, Zeynep
T1  - Fully electrochemical MIP sensor for artemisinin
JF  - Sensors and actuators : B, Chemical
N2  - This study aims to develop a rapid, sensitive and cost-effective biomimetic electrochemical sensor for artemisinin determination in plant extracts and for pharmacokinetic studies. A novel molecularly imprinted polymer (MIP)based electrochemical sensor was developed by electropolymerization of o-phenylenediamine (o-PD) in the presence of artemisinin on gold wire surface for sensitive detection of artemisinin. The experimental parameters, including selection of functional monomer, polymerization conditions, template extraction after polymerization, influence of pH and buffer were all optimized. Every step of imprinted film synthesis were evaluated by employing voltammetry techniques, surface-enhanced infrared absorption spectroscopy (SEIRAS) and atomic force microscopy (AFM). The specificity was further evaluated by investigating non-specific artemisinin binding on non-imprinted polymer (NIP) surfaces and an imprinting factor of 6.8 was achieved. The artemisinin imprinted polymers using o-PD as functional monomer have provided highly stable and effective binding cavities for artemisinin. Cross-reactivity studies with drug molecules showed that the MIPs are highly specific for artemisinin. The influence of matrix effect was further investigated both in artificial plant matrix and diluted human serum. The results revealed a high affinity of artemisinin-MIP with dissociation constant of 7.3 x 10(-9) M and with a detection limit of 0.01 mu M and 0.02 mu M in buffer and plant matrix, respectively.
KW  - Electro-synthesized molecularly imprinted polymer
KW  - o-Phenylenediamine
KW  - Artemisinin
KW  - Antimalarial drug detection
KW  - Electrochemical sensor
Y1  - 2018
U6  - https://doi.org/10.1016/j.snb.2018.08.018
SN  - 0925-4005
VL  - 275
SP  - 163
EP  - 173
PB  - Elsevier
CY  - Lausanne
ER  - 
TY  - GEN
A1  - Deng, Zijun
A1  - Wang, Weiwei
A1  - Xua, Xun
A1  - Gould, Oliver E. C.
A1  - Kratz, Karl
A1  - Ma, Nan
A1  - Lendlein, Andreas
T1  - Polymeric sheet actuators with programmable bioinstructivity
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Stem cells are capable of sensing and processing environmental inputs, converting this information to output a specific cell lineage through signaling cascades. Despite the combinatorial nature of mechanical, thermal, and biochemical signals, these stimuli have typically been decoupled and applied independently, requiring continuous regulation by controlling units. We employ a programmable polymer actuator sheet to autonomously synchronize thermal and mechanical signals applied to mesenchymal stem cells (MSC5). Using a grid on its underside, the shape change of polymer sheet, as well as cell morphology, calcium (Ca2+) influx, and focal adhesion assembly, could be visualized and quantified. This paper gives compelling evidence that the temperature sensing and mechanosensing of MSC5 are interconnected via intracellular Ca2+. Up-regulated Ca2+ levels lead to a remarkable alteration of histone H3K9 acetylation and activation of osteogenic related genes. The interplay of physical, thermal, and biochemical signaling was utilized to accelerate the cell differentiation toward osteogenic lineage. The approach of programmable bioinstructivity provides a fundamental principle for functional biomaterials exhibiting multifaceted stimuli on differentiation programs. Technological impact is expected in the tissue engineering of periosteum for treating bone defects.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1441 
KW  - reversible shape-memory actuator
KW  - mesenchymal stem cells
KW  - calcium influx
KW  - HDAC1
KW  - RUNX2
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-515490
SN  - 1866-8372
IS  - 4
ER  - 
TY  - JOUR
A1  - Vishnevetskaya, Natalya S.
A1  - Hildebrand, Viet
A1  - Nizardo, Noverra Mardhatillah
A1  - Ko, Chia-Hsin
A1  - Di, Zhenyu
A1  - Radulescu, Aurel
A1  - Barnsley, Lester C.
A1  - Müller-Buschbaum, Peter
A1  - Laschewsky, André
A1  - Papadakis, Christine M.
T1  - All-in-One "Schizophrenic" self-assembly of orthogonally tuned thermoresponsive diblock copolymers
JF  - Langmuir
N2  - Smart, fully orthogonal switching was realized in a highly biocompatible diblock copolymer system with variable trigger-induced aqueous self-assembly. The polymers are composed of nonionic and zwitterionic blocks featuring lower and upper critical solution temperatures (LCSTs and UCSTs). In the system investigated, diblock copolymers from poly(N-isopropyl methacrylamide) (PNIPMAM) and a poly(sulfobetaine methacrylamide), systematic variation of the molar mass of the latter block allowed for shifting the UCST of the latter above the LCST of the PNIPMAM block in a salt-free condition. Thus, successive thermal switching results in "schizophrenic" micellization, in which the roles of the hydrophobic core block and the hydrophilic shell block are interchanged depending on the temperature. Furthermore, by virtue of the strong electrolyte-sensitivity of the zwitterionic polysulfobetaine block, we succeeded to shift its UCST below the LCST of the PNIPMAM block by adding small amounts of an electrolyte, thus inverting the pathway of switching. This superimposed orthogonal switching by electrolyte addition enabled us to control the switching scenarios between the two types of micelles (i) via an insoluble state, if the LCST-type cloud point is below the UCST-type cloud point, which is the case at low salt concentrations or (ii) via a molecularly dissolved state, if the LCST-type cloud point is above the UCST-type cloud point, which is the case at high salt concentrations. Systematic variation of the block lengths allowed for verifying the anticipated behavior and identifying the molecular architecture needed. The versatile and tunable self-assembly offers manifold opportunities, for example, for smart emulsifiers or for sophisticated carrier systems.
Y1  - 2019
U6  - https://doi.org/10.1021/acs.langmuir.9b00241
SN  - 0743-7463
VL  - 35
IS  - 19
SP  - 6441
EP  - 6452
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Pessanha, Tatiana
A1  - Paschoalino, Waldemir J.
A1  - Deroco, Patricia B.
A1  - Kogikoski Junior, Sergio
A1  - Moraes, Ana C. M. de
A1  - Carvalho Castro de Silva, Cecilia de
A1  - Kubota, Lauro T.
T1  - Interfacial capacitance of graphene oxide films electrodes
BT  - Fundamental studies on electrolytes interface aiming (bio)sensing applications
JF  - Electroanalysis : an internatinal journal devoted to electroanalysis, sensors and bioelectronic devices
N2  - The understanding of bidimensional materials dynamics and its electrolyte interface equilibrium, such as graphene oxide (GO), is critical for the development of a capacitive biosensing platform. The interfacial capacitance (C-i) of graphene-based materials may be tuned by experimental conditions such as pH optimization and cation size playing key roles at the enhancement of their capacitive properties allowing their application as novel capacitive biosensors. Here we reported a systematic study of C-i of multilayer GO films in different aqueous electrolytes employing electrochemical impedance spectroscopy for the application in a capacitive detection system. We demonstrated that the presence of ionizable oxygen-containing functional groups within multilayer GO film favors the interactions and the accumulation of cations in the structure of the electrodes enhancing the GO C-i in aqueous solutions, where at pH 7.0 (the best condition) the C-i was 340 mu F mg(-1) at -0.01 V vs Ag/AgCl. We also established that the hydrated cation radius affects the mobility and interaction with GO functional groups and it plays a critical role in the Ci, as demonstrated in the presence of different cations Na+=640 mu F mg(-1), Li+=575 mu F mg(-1) and TMA(+)=477 mu F mg(-1). As a proof-of-concept, the capacitive behaviour of GO was explored as biosensing platform for standard streptavidin-biotin systems. For this system, the C-i varied linearly with the log of the concentration of the targeting analyte in the range from 10 pg mL(-1) to 100 ng mL(-1), showing the promising applicability of capacitive GO based sensors for label-free biosensing.
KW  - Interfacial capacitance
KW  - Graphene oxide
KW  - Functional groups
KW  - Electrochemical impedance
KW  - Graphene derivates
Y1  - 2021
U6  - https://doi.org/10.1002/elan.202100220
SN  - 1521-4109
SN  - 1040-0397
VL  - 34
IS  - 4
SP  - 692
EP  - 700
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Kihampa, Charles
A1  - Nkunya, Mayunga H. H.
A1  - Joseph, Cosam C.
A1  - Magesa, Stephen M.
A1  - Hassanali, Ahmed
A1  - Heydenreich, Matthias
A1  - Kleinpeter, Erich
T1  - Antimosquito and antimicrobial clerodanoids and a chlorobenzoid from Tessmannia species
N2  - The clerodane diterpenoids trans-kolavenolic acid, 18-oxocleroda-3,13(E)-dien-15-oic acid, ent-(18- hydroxycarbonyl)-cleroda- 3,13(E)-dien-15-oate, 2-oxo-ent-cleroda-3,13(Z)-dien-15-oic acid and trans-2-oxo-ent-cleroda- 13(Z)-en-15-oic acid, and the chlorobenzenoid O-(3-hydroxy-4-hydroxycarbonyl-5-pentylphenyl)-3-chloro-4-methoxy-6-pentyl- 2-oxybenzoic acid were isolated from Tessmannia martiniana var pauloi and T. martiniana var matiniana. Structures were established based on interpretation of spectroscopic data. Some of the compounds exhibited significant antimosquito, antifungal and antibacterial activities.
Y1  - 2010
UR  - http://www.naturalproduct.us/
SN  - 1934-578X
ER  - 
TY  - JOUR
A1  - Benassi, Rois
A1  - Bertarini, C.
A1  - Kleinpeter, Erich
A1  - Taddei, F.
A1  - Thomas, Steffen
T1  - Exocyclic push-pull conjugated compounds : Part 1 ; theoretical study of the effect of ring size on the structure, electronic properties and rotational barriers of cyclic analogoues of 1,1-diamino-2.2-dicyanoethylene
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Benassi, Rois
A1  - Bertarini, C.
A1  - Kleinpeter, Erich
A1  - Taddei, F.
T1  - Exocyclic push-pull conjugated compounds, Part 2 : the effect of donor and acceptor substituents on the rotational barrier of push-pull ethylenes
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Benassi, Rois
A1  - Bertarini, C.
A1  - Hilfert, Liane
A1  - Kempter, Gerhard
A1  - Kleinpeter, Erich
A1  - Spindler, Jürgen
A1  - Taddei, F.
A1  - Thomas, Steffen
T1  - Exocyclic push-pull conjugated compounds : Part 3
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Griel, C.
A1  - Ströhl, D.
A1  - Jeschkeit, H.
A1  - Kleinpeter, Erich
T1  - Synthetische und NMR-spektroskopische Untersuchungen der Benzzyl-aminaddition an N-Maleyl- aminosäurederivaten
Y1  - 1992
ER  - 
TY  - JOUR
A1  - Kihampa, Charles
A1  - Nkunya, Mayunga H. H.
A1  - Joseph, Cosam C.
A1  - Magesa, Stephen M.
A1  - Hassanali, Ahmed
A1  - Heydenreich, Matthias
A1  - Kleinpeter, Erich
T1  - Anti-mosquito and antimicrobial nor-halimanoids, isocoumarins and an anilinoid from Tessmannia densiflora
N2  - The nor-halimane diterpenoid tessmannic acid and its methyl, 2-methylisopropyl and 1-methylbutyl esters, the unusual isocoumarins 8-hydroxy-6-methoxy-3-pentylisocoumarin and 7-chloro-8-hydroxy-6-methoxy-3-pentylisocoumarin, and 5- pentyl-3-methoxy-N-butylaniline were isolated from the stem and root bark extracts of Tessmannia densiflora Harms (Caesalpiniaceae) that showed mosquito larvicidal activity. The structures were determined on interpretation of spectroscopic data. Tessmannic acid and its methyl ester exhibited antibacterial and antifungal activity. The compounds also caused high larvae and adult Anopheles gambiae mosquitoe mortality effects, and stronger mosquito repellency than that shown by the standard repellent DEET, hence indicating Tessmannia species to be potential sources of bioactive natural products.
Y1  - 2009
UR  - http://www.sciencedirect.com/science/journal/00319422
U6  - https://doi.org/10.1016/j.phytochem.2009.07.024
SN  - 0031-9422
ER  - 
TY  - JOUR
A1  - Kihampa, Charles
A1  - Joseph, Cosam C.
A1  - Nkunya, Mayunga H. H.
A1  - Magesa, Stephen M.
T1  - Larvicidal and IGR activity of extract of Tanzanian plants against malaria vector mosquitoes
N2  - Background & objectives: This paper reports the larvicidal activity of seventeen Tanzanian plant species against the malaria vector, Anopheles gambiae s.s. Giles larvae. Some of the plants are used traditionally as sources of insecticidal materials. Methods: The crude extracts from the leaves, stem and root barks of the investigated plants were obtained by solvent extraction and then bio-assayed following WHO protocols showed LC50 values 10 to 400 ppm after 24 h exposure. The structures were determined on interpretation of spectroscopic data. Results: The most active extracts were those from the stem and root barks of Annona squamosa, Uvaria faulknerae, U. kirkii and Uvariodendron pycnophyllum, all of which had LC50 values between 10 and 100 ppm. Long-term exposure beyond 24 h also showed more susceptibility of the larvae to the extracts. Larvae deformities by forming tail-like structures were observed for the methanol extracts of Tessmannia martiniana var pauloi. Interpretation & conclusion: The results suggest that the investigated plant extracts are promising as larvicides against An. gambiae s.s. Giles mosquitoes and could be useful leads in the search for new and biodegradable plant derived larvicide products.
Y1  - 2009
UR  - http://www.mrcindia.org/journal/
SN  - 0972-9062
ER  - 
TY  - JOUR
A1  - Ryppa, C.
A1  - Senge, Mathias O.
A1  - Hatscher, S. S.
A1  - Kleinpeter, Erich
A1  - Wacker, Philipp
A1  - Schilde, Uwe
A1  - Wiehe, A.
T1  - Synthesis of mono- and disubstituted porphyrins : A- and 5,10-A(2)-type systems
N2  - General syntheses have been developed for meso-substituted porphyrins with one or two substituents in the 5,10- positions and no beta substituents. 5-Substituted porphyrins with only one meso substituent are easily prepared by an acid-catalyzed condensation of dipyrromethane, pyrrole-2-carbaldehyde. and an appropriate aldehyde using a "[2+1+1]" approach. Similarly, 5,10-disubstituted porphyrins are accessible by simple condensation of unsubstituted tripyrrane with pyrrole and various aldehydes using a "[3+1]" approach. The yields for these reactions are low to moderate and additional formation of either di- or mono-substituted porphyrins due to scrambling of the intermediates is observed. However, the reactions can be performed quite easily and the desired target compounds are easily removed due to large differences in solubility. A complementary and more selective synthesis involves the use of organolithium reagents for SNAr reactions. Reaction of in situ generated porphyrin (porphine) with 1.1-8 equivalents of RLi gave the monosubstituted porphyrins, while reaction with 3-6 equivalents of RLi gave the 5,10-disubstituted porphyrins in yields ranging from 43 to 90%. These hitherto almost inaccessible compounds complete the series of different homologues of A-, 5,15-A(2)-, 5,10-A(2)-, A(3)-, and A(4)-type porphyrin's and allow an investigation of the gradual influence of type, number, and regiochemical arrangement of substituents on the properties of meso-substituted porphyrins. They also present important starting materials for the synthesis of ABCD porphyrins and are potential synthons for supramolecular materials requiring specific substituent orientations
Y1  - 2005
SN  - 0947-6539
ER  - 
TY  - JOUR
A1  - Balci, K.
A1  - Akkaya, Y.
A1  - Akyuz, S.
A1  - Collier, W. B.
A1  - Stricker, M. C.
A1  - Stover, D. D.
A1  - Ritzhaupt, G.
A1  - Koch, Andreas
A1  - Kleinpeter, Erich
T1  - The effects of conformation and zwitterionic tautomerism on the structural and vibrational spectral data of anserine
JF  - Vibrational spectroscopy : an international journal devoted to applications of infrared and raman spectroscopy
N2  - In this study, the stable conformers of neutral anserine were searched by molecular dynamics simulations and energy minimization calculations using the MM2 force field. Thermochemical calculations at B3LYP/6-31G(d) level of theory followed these preliminary calculations. The results confirmed that neutral anserine has quite a flexible structure and many stable gauche and trans conformers at room temperature. Nevertheless, two are considerably more favourable in energy than the others and expected to dominate the gas-phase and matrix IR spectra of the molecule. The corresponding structural and vibrational spectral data for these two conformers of neutral anserine, whose relative stabilities were also examined by high-accuracy energy calculations carried out using G3MP2B3 method, and for the most stable conformer of anserine in zwitterion form were calculated at B3LYP/6-311++G(d,p) level of theory. The calculated harmonic force constants were refined using the Scaled Quantum Mechanical Force Field (SQM-FF) method and then used to produce the refined wavenumbers, potential energy distributions (PEDs) and IR and Raman intensities. These refined data together with the scaled harmonic wavenumbers obtained using another method, Dual Scale factors (DS), enabled us to correctly analyse the observed IR and Raman spectra of anserine and revealed the effects of conformation and zwitterionic tautomerism on its structural and vibrational spectral data. (C) 2016 Elsevier B.V. All rights reserved.
KW  - Anserine
KW  - Matrix IR spectrum
KW  - Tautomerism
KW  - SQM-FF
KW  - Dual scale factors
Y1  - 2016
U6  - https://doi.org/10.1016/j.vibspec.2016.08.003
SN  - 0924-2031
SN  - 1873-3697
VL  - 86
SP  - 277
EP  - 289
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Deng, Zijun
A1  - Wang, Weiwei
A1  - Xua, Xun
A1  - Gould, Oliver E. C.
A1  - Kratz, Karl
A1  - Ma, Nan
A1  - Lendlein, Andreas
T1  - Polymeric sheet actuators with programmable bioinstructivity
JF  - PNAS
N2  - Stem cells are capable of sensing and processing environmental inputs, converting this information to output a specific cell lineage through signaling cascades. Despite the combinatorial nature of mechanical, thermal, and biochemical signals, these stimuli have typically been decoupled and applied independently, requiring continuous regulation by controlling units. We employ a programmable polymer actuator sheet to autonomously synchronize thermal and mechanical signals applied to mesenchymal stem cells (MSC5). Using a grid on its underside, the shape change of polymer sheet, as well as cell morphology, calcium (Ca2+) influx, and focal adhesion assembly, could be visualized and quantified. This paper gives compelling evidence that the temperature sensing and mechanosensing of MSC5 are interconnected via intracellular Ca2+. Up-regulated Ca2+ levels lead to a remarkable alteration of histone H3K9 acetylation and activation of osteogenic related genes. The interplay of physical, thermal, and biochemical signaling was utilized to accelerate the cell differentiation toward osteogenic lineage. The approach of programmable bioinstructivity provides a fundamental principle for functional biomaterials exhibiting multifaceted stimuli on differentiation programs. Technological impact is expected in the tissue engineering of periosteum for treating bone defects.
KW  - reversible shape-memory actuator
KW  - mesenchymal stem cells
KW  - calcium influx
KW  - HDAC1
KW  - RUNX2
Y1  - 2020
U6  - https://doi.org/10.1073/pnas.1910668117
SN  - 1091-6490
VL  - 117
IS  - 4
SP  - 1895
EP  - 1901
PB  - National Academy of Sciences
CY  - Washington, DC
ER  - 
TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Koch, Andreas
A1  - Fischer, G.
A1  - Askolin, C.-P.
T1  - 13 C NMR, 15 N NMR and quantum-chemical study of the tautomerism of 2-substituted 5-ME-7-OH-1,2,4-triazolo[1,5- a]pyrimidines
Y1  - 1997
ER  -