@article{LiBenduhnQiaoetal.2019, author = {Li, Tian-yi and Benduhn, Johannes and Qiao, Zhi and Liu, Yuan and Li, Yue and Shivhare, Rishi and Jaiser, Frank and Wang, Pei and Ma, Jie and Zeika, Olaf and Neher, Dieter and Mannsfeld, Stefan C. B. and Ma, Zaifei and Vandewal, Koen and Leo, Karl}, title = {Effect of H- and J-Aggregation on the Photophysical and Voltage Loss of Boron Dipyrromethene Small Molecules in Vacuum-Deposited Organic Solar Cells}, series = {The journal of physical chemistry letters}, volume = {10}, journal = {The journal of physical chemistry letters}, number = {11}, publisher = {American Chemical Society}, address = {Washington}, issn = {1948-7185}, doi = {10.1021/acs.jpclett.9b01222}, pages = {2684 -- 2691}, year = {2019}, abstract = {An understanding of the factors limiting the open-circuit voltage (V-oc) and related photon energy loss mechanisms is critical to increase the power conversion efficiency (PCE) of small-molecule organic solar cells (OSCs), especially those with near-infrared (NIR) absorbers. In this work, two NIR boron dipyrromethene (BODIPY) molecules are characterized for application in planar (PHJ) and bulk (BHJ) heterojunction OSCs. When two H atoms are substituted by F atoms on the peripheral phenyl rings of the molecules, the molecular aggregation type in the thin film changes from the H-type to J-type. For PHJ devices, the nonradiative voltage loss of 0.35 V in the J-aggregated BODIPY is lower than that of 0.49 V in the H-aggregated device. In BHJ devices with a nonradiative voltage loss of 0.35 V, a PCE of 5.5\% is achieved with an external quantum efficiency (EQE) maximum of 68\% at 700 nm.}, language = {en} } @article{LiGaoSchlaichetal.2017, author = {Li, Mingjun and Gao, Lingyan and Schlaich, Christoph and Zhang, Jianguang and Donskyi, Ievgen S. and Yu, Guozhi and Li, Wenzhong and Tu, Zhaoxu and Rolff, Jens and Schwerdtle, Tanja and Haag, Rainer and Ma, Nan}, title = {Construction of Functional Coatings with Durable and Broad-Spectrum Antibacterial Potential Based on Mussel-Inspired Dendritic Polyglycerol and in Situ-Formed Copper Nanoparticles}, series = {ACS applied materials \& interfaces}, volume = {9}, journal = {ACS applied materials \& interfaces}, publisher = {American Chemical Society}, address = {Washington}, issn = {1944-8244}, doi = {10.1021/acsami.7b10541}, pages = {35411 -- 35418}, year = {2017}, abstract = {A novel surface coating with durable broad-spectrum antibacterial ability was prepared based on mussel inspired dendritic polyglycerol (MI-dPG) embedded with copper nanoparticles (Cu NPs). The functional surface coating is fabricated via a facile dip-coating process followed by in situ reduction of copper ions with a MI-dPG coating to introduce Cu NPs into the coating matrix. This coating has been demonstrated to possess efficient long-term antibacterial properties against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and kanamycin-resistant E. coli through an "attract-kill-release" strategy. The synergistic antibacterial activity of the coating was shown by the combination of two functions of the contact killing, reactive oxygen species production and Cu ions released from the coating. Furthermore, this coating inhibited biofilm formation and showed good compatibility to eukaryotic cells. Thus, this newly developed Cu NP-incorporated MI-dPG surface coating may find potential application in the design of antimicrobial coating, such as implantable devices.}, language = {en} } @article{FangMaLietal.2017, author = {Fang, Peng and Ma, Xingchen and Li, Xiangxin and Qiu, Xunlin and Gerhard, Reimund and Zhang, Xiaoqing and Li, Guanglin}, title = {Fabrication, Structure Characterization, and Performance Testing of Piezoelectret-Film Sensors for Recording Body Motion}, series = {IEEE Sensors Journal}, volume = {18}, journal = {IEEE Sensors Journal}, number = {1}, publisher = {Inst. of Electr. and Electronics Engineers}, address = {Piscataway}, issn = {1530-437X}, doi = {10.1109/JSEN.2017.2766663}, pages = {401 -- 412}, year = {2017}, abstract = {During muscle contractions, radial-force distributions are generated on muscle surfaces due to muscle-volume changes, from which the corresponding body motions can be recorded by means of so-called force myography (FMG). Piezo- or ferroelectrets are flexible piezoelectric materials with attractive materials and sensing properties. In addition to several other applications, they are suitable for detecting force variations by means of wearable devices. In this paper, we prepared piezoelectrets from cellular polypropylene films by optimizing the fabrication procedures, and developed an FMG-recording system based on piezoelectret sensors. Different hand and wrist movements were successfully detected on able-bodied subjects with the FMG system. The FMG patterns were evaluated and identified by means of linear discriminant analysis and artificial neural network algorithms, and average motion-classification accuracies of 96.1\% and 94.8\%, respectively, were obtained. This paper demonstrates the feasibility of using piezoelectret-film sensors for FMG and may thus lead to alternative methods for detecting body motion and to related applications, e.g., in biomedical engineering or structural-health monitoring.}, language = {en} } @article{LiBenduhnLietal.2018, author = {Li, Tian-yi and Benduhn, Johannes and Li, Yue and Jaiser, Frank and Spoltore, Donato and Zeika, Olaf and Ma, Zaifei and Neher, Dieter and Vandewal, Koen and Leo, Karl}, title = {Boron dipyrromethene (BODIPY) with meso-perfluorinated alkyl substituents as near infrared donors in organic solar cells}, series = {Journal of materials chemistry : A, Materials for energy and sustainability}, volume = {6}, journal = {Journal of materials chemistry : A, Materials for energy and sustainability}, number = {38}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2050-7488}, doi = {10.1039/c8ta06261g}, pages = {18583 -- 18591}, year = {2018}, abstract = {Three furan-fused BODIPYs were synthesized with perfluorinated methyl, ethyl and n-propyl groups on the meso-carbon. They were obtained with high yields by reacting the furan-fused 2-carboxylpyrrole in corresponding perfluorinated acid and anhydride. With the increase in perfluorinated alkyl chain length, the molecular packing in the single crystal is influenced, showing increasing stacking distance and decreasing slope angle. All the BODIPYs were characterized as intense absorbers in near infrared region in solid state, peaking at similar to 800 nm with absorption coefficient of over 280 000 cm(-1). Facilitated by high thermal stability, the furan-fused BODIPYs were employed in vacuum-deposited organic solar cells as electron donors. All devices exhibit PCE over 6.0\% with the EQE maximum reaching 70\% at similar to 790 nm. The chemical modification of the BODIPY donors have certain influence on the active layer morphology, and the highest PCE of 6.4\% was obtained with a notably high jsc of 13.6 mA cm(-2). Sensitive EQE and electroluminance studies indicated that the energy losses generated by the formation of a charge transfer state and the radiative recombination at the donor-acceptor interface were comparable in the range of 0.14-0.19 V, while non-radiative recombination energy loss of 0.38 V was the main energy loss route resulting in the moderate V-oc of 0.76 V.}, language = {en} } @book{MaChen2004, author = {Ma, Li and Chen, Dezhong}, title = {Curve Shotening in a Riemannian Manifold}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell}, publisher = {Univ.}, address = {Potsdam}, issn = {1437-739X}, pages = {20 S.}, year = {2004}, language = {en} } @article{MaLiKempkaetal.2019, author = {Ma, Jianli and Li, Qi and Kempka, Thomas and K{\"u}hn, Michael}, title = {Hydromechanical response and impact of gas mixing behavior in subsurface CH4 storage with CO2-based cushion gas}, series = {Energy \& fuels}, volume = {33}, journal = {Energy \& fuels}, number = {7}, publisher = {American Chemical Society}, address = {Washington}, issn = {0887-0624}, doi = {10.1021/acs.energyfuels.9b00518}, pages = {6527 -- 6541}, year = {2019}, abstract = {Power-to-gas (PtG) stores chemical energy by converting excess electrical energy from renewable sources into an energy-dense gas. Due to its higher available capacity compared to surface-based storage technologies, subsurface storage in geological systems is the most promising approach for efficient and economic realization of the PtG system's storage component. For this purpose, methane (CH4) produced by methanation by means of hydrogen (H2) and carbon dioxide (CO2) is stored in a geological reservoir until required for further use. In this context, CO2 is used as the cushion gas to maintain reservoir pressure and limiting working gas, i.e., (CH4) losses during withdrawal periods. Consequently, mixing of both gases in the reservoir is inevitable. Therefore, it is necessary to minimize the gas mixing region to optimize the efficiency of the PtG system's storage component. In the present study, the physical properties of CH4, CO2 and their mixtures are reviewed. Then, a multicomponent flow model is implemented and validated against published data. Next, a hydromechanically coupled model is established, considering fluid flow through porous media and effective stresses to investigate the mixing behavior of both gases and the mechanical reservoir stability. The simulation results show that, with increasing reservoir thickness and dip angle, the mixing region is reduced during gas injection if CO2 is employed as the cushion gas. In addition, the degree of mixing is lower at higher temperatures. Feasible injection rates and injection schedules can be derived from the integrated reservoir stability analysis. The methodology developed in the present study allows the determination of optimum strategies for storage reservoir selection and gas injection scheduling by minimizing the gas mixing region.}, language = {en} } @article{MiddeldorpMahajanHorikoshietal.2019, author = {Middeldorp, Christel M. and Mahajan, Anubha and Horikoshi, Momoko and Robertson, Neil R. and Beaumont, Robin N. and Bradfield, Jonathan P. and Bustamante, Mariona and Cousminer, Diana L. and Day, Felix R. and De Silva, N. Maneka and Guxens, Monica and Mook-Kanamori, Dennis O. and St Pourcain, Beate and Warrington, Nicole M. and Adair, Linda S. and Ahlqvist, Emma and Ahluwalia, Tarunveer Singh and Almgren, Peter and Ang, Wei and Atalay, Mustafa and Auvinen, Juha and Bartels, Meike and Beckmann, Jacques S. and Bilbao, Jose Ramon and Bond, Tom and Borja, Judith B. and Cavadino, Alana and Charoen, Pimphen and Chen, Zhanghua and Coin, Lachlan and Cooper, Cyrus and Curtin, John A. and Custovic, Adnan and Das, Shikta and Davies, Gareth E. and Dedoussis, George V. and Duijts, Liesbeth and Eastwood, Peter R. and Eliasen, Anders U. and Elliott, Paul and Eriksson, Johan G. and Estivill, Xavier and Fadista, Joao and Fedko, Iryna O. and Frayling, Timothy M. and Gaillard, Romy and Gauderman, W. James and Geller, Frank and Gilliland, Frank and Gilsanz, Vincente and Granell, Raquel and Grarup, Niels and Groop, Leif and Hadley, Dexter and Hakonarson, Hakon and Hansen, Torben and Hartman, Catharina A. and Hattersley, Andrew T. and Hayes, M. Geoffrey and Hebebrand, Johannes and Heinrich, Joachim and Helgeland, Oyvind and Henders, Anjali K. and Henderson, John and Henriksen, Tine B. and Hirschhorn, Joel N. and Hivert, Marie-France and Hocher, Berthold and Holloway, John W. and Holt, Patrick and Hottenga, Jouke-Jan and Hypponen, Elina and Iniguez, Carmen and Johansson, Stefan and Jugessur, Astanand and Kahonen, Mika and Kalkwarf, Heidi J. and Kaprio, Jaakko and Karhunen, Ville and Kemp, John P. and Kerkhof, Marjan and Koppelman, Gerard H. and Korner, Antje and Kotecha, Sailesh and Kreiner-Moller, Eskil and Kulohoma, Benard and Kumar, Ashish and Kutalik, Zoltan and Lahti, Jari and Lappe, Joan M. and Larsson, Henrik and Lehtimaki, Terho and Lewin, Alexandra M. and Li, Jin and Lichtenstein, Paul and Lindgren, Cecilia M. and Lindi, Virpi and Linneberg, Allan and Liu, Xueping and Liu, Jun and Lowe, William L. and Lundstrom, Sebastian and Lyytikainen, Leo-Pekka and Ma, Ronald C. W. and Mace, Aurelien and Magi, Reedik and Magnus, Per and Mamun, Abdullah A. and Mannikko, Minna and Martin, Nicholas G. and Mbarek, Hamdi and McCarthy, Nina S. and Medland, Sarah E. and Melbye, Mads and Melen, Erik and Mohlke, Karen L. and Monnereau, Claire and Morgen, Camilla S. and Morris, Andrew P. and Murray, Jeffrey C. and Myhre, Ronny and Najman, Jackob M. and Nivard, Michel G. and Nohr, Ellen A. and Nolte, Ilja M. and Ntalla, Ioanna and Oberfield, Sharon E. and Oken, Emily and Oldehinkel, Albertine J. and Pahkala, Katja and Palviainen, Teemu and Panoutsopoulou, Kalliope and Pedersen, Oluf and Pennell, Craig E. and Pershagen, Goran and Pitkanen, Niina and Plomin, Robert and Power, Christine and Prasad, Rashmi B. and Prokopenko, Inga and Pulkkinen, Lea and Raikkonen, Katri and Raitakari, Olli T. and Reynolds, Rebecca M. and Richmond, Rebecca C. and Rivadeneira, Fernando and Rodriguez, Alina and Rose, Richard J. and Salem, Rany and Santa-Marina, Loreto and Saw, Seang-Mei and Schnurr, Theresia M. and Scott, James G. and Selzam, Saskia and Shepherd, John A. and Simpson, Angela and Skotte, Line and Sleiman, Patrick M. A. and Snieder, Harold and Sorensen, Thorkild I. A. and Standl, Marie and Steegers, Eric A. P. and Strachan, David P. and Straker, Leon and Strandberg, Timo and Taylor, Michelle and Teo, Yik-Ying and Thiering, Elisabeth and Torrent, Maties and Tyrrell, Jessica and Uitterlinden, Andre G. and van Beijsterveldt, Toos and van der Most, Peter J. and van Duijn, Cornelia M. and Viikari, Jorma and Vilor-Tejedor, Natalia and Vogelezang, Suzanne and Vonk, Judith M. and Vrijkotte, Tanja G. M. and Vuoksimaa, Eero and Wang, Carol A. and Watkins, William J. and Wichmann, H-Erich and Willemsen, Gonneke and Williams, Gail M. and Wilson, James F. and Wray, Naomi R. and Xu, Shujing and Xu, Cheng-Jian and Yaghootkar, Hanieh and Yi, Lu and Zafarmand, Mohammad Hadi and Zeggini, Eleftheria and Zemel, Babette S. and Hinney, Anke and Lakka, Timo A. and Whitehouse, Andrew J. O. and Sunyer, Jordi and Widen, Elisabeth E. and Feenstra, Bjarke and Sebert, Sylvain and Jacobsson, Bo and Njolstad, Pal R. and Stoltenberg, Camilla and Smith, George Davey and Lawlor, Debbie A. and Paternoster, Lavinia and Timpson, Nicholas J. and Ong, Ken K. and Bisgaard, Hans and Bonnelykke, Klaus and Jaddoe, Vincent W. V. and Tiemeier, Henning and Jarvelin, Marjo-Riitta and Evans, David M. and Perry, John R. B. and Grant, Struan F. A. and Boomsma, Dorret I. and Freathy, Rachel M. and McCarthy, Mark I. and Felix, Janine F.}, title = {The Early Growth Genetics (EGG) and EArly Genetics and Lifecourse Epidemiology (EAGLE) consortia}, series = {European journal of epidemiology}, volume = {34}, journal = {European journal of epidemiology}, number = {3}, publisher = {Springer}, address = {Dordrecht}, organization = {EArly Genetics Lifecourse EGG Consortium EGG Membership EAGLE Membership}, issn = {0393-2990}, doi = {10.1007/s10654-019-00502-9}, pages = {279 -- 300}, year = {2019}, abstract = {The impact of many unfavorable childhood traits or diseases, such as low birth weight and mental disorders, is not limited to childhood and adolescence, as they are also associated with poor outcomes in adulthood, such as cardiovascular disease. Insight into the genetic etiology of childhood and adolescent traits and disorders may therefore provide new perspectives, not only on how to improve wellbeing during childhood, but also how to prevent later adverse outcomes. To achieve the sample sizes required for genetic research, the Early Growth Genetics (EGG) and EArly Genetics and Lifecourse Epidemiology (EAGLE) consortia were established. The majority of the participating cohorts are longitudinal population-based samples, but other cohorts with data on early childhood phenotypes are also involved. Cohorts often have a broad focus and collect(ed) data on various somatic and psychiatric traits as well as environmental factors. Genetic variants have been successfully identified for multiple traits, for example, birth weight, atopic dermatitis, childhood BMI, allergic sensitization, and pubertal growth. Furthermore, the results have shown that genetic factors also partly underlie the association with adult traits. As sample sizes are still increasing, it is expected that future analyses will identify additional variants. This, in combination with the development of innovative statistical methods, will provide detailed insight on the mechanisms underlying the transition from childhood to adult disorders. Both consortia welcome new collaborations. Policies and contact details are available from the corresponding authors of this manuscript and/or the consortium websites.}, language = {en} } @article{LiXuWangetal.2017, author = {Li, Zhengdong and Xu, Xun and Wang, Weiwei and Kratz, Karl and Sun, Xianlei and Zou, Jie and Deng, Zijun and Jung, Friedrich Wilhelm and Gossen, Manfred and Ma, Nan and Lendlein, Andreas}, title = {Modulation of the mesenchymal stem cell migration capacity via preconditioning with topographic microstructure}, series = {Clinical hemorheology and microcirculation : blood flow and vessels}, volume = {67}, journal = {Clinical hemorheology and microcirculation : blood flow and vessels}, publisher = {IOS Press}, address = {Amsterdam}, issn = {1386-0291}, doi = {10.3233/CH-179208}, pages = {267 -- 278}, year = {2017}, abstract = {Controlling mesenchymal stem cells (MSCs) behavior is necessary to fully exploit their therapeutic potential. Various approaches are employed to effectively influence the migration capacity of MSCs. Here, topographic microstructures with different microscale roughness were created on polystyrene (PS) culture vessel surfaces as a feasible physical preconditioning strategy to modulate MSC migration. By analyzing trajectories of cells migrating after reseeding, we demonstrated that the mobilization velocity of human adipose derived mesenchymal stem cells (hADSCs) could be promoted by and persisted after brief preconditioning with the appropriate microtopography. Moreover, the elevated activation levels of focal adhesion kinase (FAK) and mitogen-activated protein kinase (MAPK) in hADSCs were also observed during and after the preconditioning process. These findings underline the potential enhancement of in vivo therapeutic efficacy in regenerative medicine via transplantation of topographic microstructure preconditioned stem cells.}, language = {en} } @article{ZouWangNeffeetal.2017, author = {Zou, Jie and Wang, Weiwei and Neffe, Axel T. and Xu, Xun and Li, Zhengdong and Deng, Zijun and Sun, Xianlei and Ma, Nan and Lendlein, Andreas}, title = {Adipogenic differentiation of human adipose derived mesenchymal stem cells in 3D architectured gelatin based hydrogels (ArcGel)}, series = {Clinical hemorheology and microcirculation : blood flow and vessels}, volume = {67}, journal = {Clinical hemorheology and microcirculation : blood flow and vessels}, number = {3-4}, publisher = {IOS Press}, address = {Amsterdam}, issn = {1386-0291}, doi = {10.3233/CH-179210}, pages = {297 -- 307}, year = {2017}, abstract = {Polymeric matrices mimicking multiple functions of the ECM are expected to enable a material induced regeneration of tissues. Here, we investigated the adipogenic differentiation of human adipose derived mesenchymal stem cells (hADSCs) in a 3D architectured gelatin based hydrogel (ArcGel) prepared from gelatin and L-lysine diisocyanate ethyl ester (LDI) in an one-step process, in which the formation of an open porous morphology and the chemical network formation were integrated. The ArcGel was designed to support adipose tissue regeneration with its 3D porous structure, high cell biocompatibility, and mechanical properties compatible with human subcutaneous adipose tissue. The ArcGel could support initial cell adhesion and survival of hADSCs. Under static culture condition, the cells could migrate into the inner part of the scaffold with a depth of 840 +/- 120 mu m after 4 days, and distributed in the whole scaffold (2mm in thickness) within 14 days. The cells proliferated in the scaffold and the fold increase of cell number after 7 days of culture was 2.55 +/- 0.08. The apoptotic rate of hADSCs in the scaffold was similar to that of cells maintained on tissue culture plates. When cultured in adipogenic induction medium, the hADSCs in the scaffold differentiated into adipocytes with a high efficiency (93 +/- 1\%). Conclusively, this gelatin based 3D scaffold presented high cell compatibility for hADSC cultivation and differentiation, which could serve as a potential implant material in clinical applications for adipose tissue reparation and regeneration.}, language = {en} } @book{LiXingwang2001, author = {Li, Ma and Xingwang, Xu}, title = {Positive solutions of a logistic equation on unbounded intervals}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Mathematik, Arbeitsgruppe Partiell}, publisher = {Univ.}, address = {Potsdam}, issn = {1437-739X}, pages = {13 S.}, year = {2001}, language = {en} }