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Same patient, new stone composition: amprenavir urinary stone

Antje Feicke, Katharina M Rentsch, Daniel Oertle, Räto T Strebel
2008 Antiviral Therapy  
We report here the first case to add amprenavir to the growing list of antiretroviral drugs associated with urinary stones. The first reported case of a nelfinavir urinary stone was reported in 2002 in a 37-year-old HIV-infected woman. In September 2007, the same female patient was referred to our department with recent onset of right flank pain and recurrent urinary tract infections. Abdominal computed tomography revealed three obstructing stones in the distal right ureter, another stone in
more » ... right renal pelvis with hydronephrosis and a stone in the left kidney. After stone retrieval, analysis of the stone by liquid chromatography with mass spectrometry revealed a stone composition of 95% unmodified amprenavir and 5% ritonavir.
pmid:18771058 fatcat:2ibm4oyrdvak7bc2kcrmim7rky

Direct Rehydrogenation of LiBH4 from H-Deficient Li2B12H12−x

Yigang Yan, Hui Wang, Min Zhu, Weitong Cai, Daniel Rentsch, Arndt Remhof
2018 Crystals  
Li 2 B 12 H 12 is commonly considered as a boron sink hindering the reversible hydrogen sorption of LiBH 4 . Recently, in the dehydrogenation process of LiBH 4 an amorphous H-deficient Li 2 B 12 H 12−x phase was observed. In the present study, we investigate the rehydrogenation properties of Li 2 B 12 H 12−x to form LiBH 4 . With addition of nanostructured cobalt boride in a 1:1 mass ratio, the rehydrogenation properties of Li 2 B 12 H 12−x are improved, where LiBH 4 forms under milder
more » ... s (e.g., 400 • C, 100 bar H 2 ) with a yield of 68%. The active catalytic species in the reversible sorption reaction is suggested to be nonmetallic Co x B (x = 1) based on 11 B MAS NMR experiments and its role has been discussed.
doi:10.3390/cryst8030131 fatcat:qzp54wqexfdylorqyx43confve

Enzymatic Synthesis of Lignin-Based Concrete Dispersing Agents

Dagmara Jankowska, Tobias Heck, Mark Schubert, Alpaslan Yerlikaya, Christophe Weymuth, Daniel Rentsch, Irene Schober, Michael Richter
2018 ChemBioChem  
Lignin is the most abundant aromatic biopolymer functioning as an integral compound of woody materials. In its unmodified form it shows limited water solubility and is relatively unreactive and thus, biotechnological lignin valorisation for high performance applications is highly underexploited. Lignin can be obtained from the pulp and paper industry as a byproduct. To expand its application, a new synthesis route towards novel dispersing agents for the use as concrete additives was developed.
more » ... he route relies on a lignin functionalization by enzymatic transformation. Screening of lignin modifying systems resulted in functionalized lignin polymers with improved solubility in aqueous systems. Due to grafting of sulfanilic acid or p-aminobenzoic acid by fungal laccases, lignin became soluble in water at pH≤4 or pH≤7, respectively. Products were analysed and evaluated in miniaturized application tests in cement paste and mortar. Their dispersing properties match performance criteria of commercially available lignosulfonates. The study exemplifies new perspectives for the use of lignin.
doi:10.1002/cbic.201800064 pmid:29543396 fatcat:iibnfno7sfglrfwn43pr3bzkiq

Visual object working memory function and clinical symptoms in schizophrenia

Sohee Park, Jörg Püschel, Barbara H Sauter, Markus Rentsch, Daniel Hell
2003 Schizophrenia Research  
Objective: The presence of working memory deficits suggests abnormalities of prefrontal cortex (PFC) in schizophrenia. Although much is known about spatial working memory deficits in schizophrenia, including its potential as a phenotypic marker, it is unclear whether object working memory is similarly affected. Our goal was to examine nonspatial, object working memory function in relation to clinical symptoms. Methods: We assessed object working memory and clinical symptoms in 28 schizophrenia
more » ... atients during acute psychotic episode and 4 months later during partial remission. Delayed-matching-to-sample tasks for familiar object (DMTS-F) and novel shapes (DMTS-N) were used. Symptoms were assessed by the Positive and Negative Syndrome Scale (PANSS). 33 age-matched normal subjects were also tested over the same time period. Results: Acutely psychotic patients showed deficits in both DMTS-F and DMTS-N. Four months later, their DMTS-F performance improved significantly but deficits in DMTS-N were still present. During acute psychosis, symptoms correlated with DMTS-F but not with the DMTS-N. Four months later, negative symptoms correlated with both tasks. Conclusions: Object working memory as measured by DMTS-N was impaired in schizophrenia patients during both acute and chronic states. When schizophrenia patients were in partial remission, object working memory was associated with negative symptoms. D
doi:10.1016/s0920-9964(02)00209-8 pmid:12414083 fatcat:np7epp224zdctgnods54or4ufm

Ureido Functionalization through Amine-Urea Transamidation under Mild Reaction Conditions

Natalia Guerrero-Alburquerque, Shanyu Zhao, Daniel Rentsch, Matthias M. Koebel, Marco Lattuada, Wim J. Malfait
2021 Polymers  
Ureido-functionalized compounds play an indispensable role in important biochemical processes, as well as chemical synthesis and production. Isocyanates, and KOCN in particular, are the preferred reagents for the ureido functionalization of amine-bearing compounds. In this study, we evaluate the potential of urea as a reagent to graft ureido groups onto amines at relatively low temperatures (<100 °C) in aqueous media. Urea is an inexpensive, non-toxic and biocompatible potential alternative to
more » ... OCN for ureido functionalization. From as early as 1864, urea was the go-to reagent for polyurea polycondensation, before falling into disuse after the advent of isocyanate chemistry. We systematically re-investigate the advantages and disadvantages of urea for amine transamidation. High ureido-functionalization conversion was obtained for a wide range of substrates, including primary and secondary amines and amino acids. Reaction times are nearly independent of substrate and pH, but excess urea is required for practically feasible reaction rates. Near full conversion of amines into ureido can be achieved within 10 h at 90 °C and within 24 h at 80 °C, and much slower reaction rates were determined at lower temperatures. The importance of the urea/amine ratio and the temperature dependence of the reaction rates indicate that urea decomposition into an isocyanic acid or a carbamate intermediate is the rate-limiting step. The presence of water leads to a modest increase in reaction rates, but the full conversion of amino groups into ureido groups is also possible in the absence of water in neat alcohol, consistent with a reaction mechanism mediated by an isocyanic acid intermediate (where the water assists in the proton transfer). Hence, the reaction with urea avoids the use of toxic isocyanate reagents by in situ generation of the reactive isocyanate intermediate, but the requirement to separate the excess urea from the reaction product remains a major disadvantage.
doi:10.3390/polym13101583 pmid:34069157 fatcat:4sfb5uxyangb5h4wregaysmeyq

The role of MgB12H12 in the hydrogen desorption process of Mg(BH4)2

Yigang Yan, Arndt Remhof, Daniel Rentsch, Andreas Züttel
2015 Chemical Communications  
Throughout the solid-state decomposition process of Mg(BH4)2, the MgB12H12 phase does not exist in the solid residues after decomposition.
doi:10.1039/c4cc05266h pmid:25417944 fatcat:o2r7onkuovbp5iun2qod7feffi

Synthesis of alkali-silica reaction product structurally identical to that formed in field concrete

Zhenguo Shi, Andreas Leemann, Daniel Rentsch, Barbara Lothenbach
2020 Materials & design  
Daniel Rentsch: Methodology, Investigation, Writing -review & editing. Barbara Lothenbach: Conceptualization, Methodology, Investigation, Writing -review & editing.  ... 
doi:10.1016/j.matdes.2020.108562 fatcat:3pbnfc6gjferxkhep2kpf6igv4

Nido ‐Hydroborate‐Based Electrolytes for All‐Solid‐State Lithium Batteries

SeyedHosein Payandeh, Daniel Rentsch, Zbigniew Łodziana, Ryo Asakura, Laurent Bigler, Radovan Černý, Corsin Battaglia, Arndt Remhof
2021 Advanced Functional Materials  
www.afm-journal.de (1 of 12) Hydroborate-based solid electrolytes have recently been successfully employed in high voltage, room temperature all-solid-state sodium batteries. The transfer to analogous lithium systems has failed up to now due to the lower conductivity of the corresponding lithium compounds and their high cost. Here LiB 11 H 14 nido-hydroborate as a cost-effective building block and its high-purity synthesis is introduced. The crystal structures of anhydrous LiB 11 H 14 as well
more » ... of LiB 11 H 14based mixed-anion solid electrolytes are solved and high ionic conductivities of 1.1 × 10 −4 S cm −1 for Li 2 (B 11 H 14 )(CB 11 H 12 ) and 1.1 × 10 −3 S cm −1 for Li 3 (B 11 H 14 )(CB 9 H 10 ) 2 are obtained, respectively. LiB 11 H 14 exhibits an oxidative stability limit of 2.6 V versus Li + /Li and the proposed decomposition products are discussed based on density functional theory calculations. Strategies are discussed to improve the stability of these compounds by modifying the chemical structure of the nido-hydroborate cage. Galvanostatic cycling in symmetric cells with two lithium metal electrodes shows a small overpotential increase from 22.5 to 30 mV after 620 h (up to 0.5 mAh cm −2 ), demonstrating that the electrolyte is compatible with metallic anodes. Finally, the Li 2 (B 11 H 14 )(CB 11 H 12 ) electrolyte is employed in a proof-of-concept half cell with a TiS 2 cathode with a capacity retention of 82% after 150 cycles at C/5.
doi:10.1002/adfm.202010046 fatcat:h65mukn6r5fjtkdelrxsz5w7ga

A novel strategy for reversible hydrogen storage in Ca(BH4)2

Yigang Yan, Arndt Remhof, Daniel Rentsch, Andreas Züttel, Santanab Giri, Puru Jena
2015 Chemical Communications  
The reversible hydrogen storage in Ca(BH4)2 at moderate conditions involves CaB2H6 as a crucial reaction intermediate.
doi:10.1039/c5cc03605d pmid:26008181 fatcat:oq5cgoexlfflfbacjsa2kn4ci4

Influence of sodium nitrate on the phases formed in the MgO-Al2O3-SiO2-H2O system

Ellina Bernard, Barbara Lothenbach, Daniel Rentsch
2020 Materials & design  
Rentsch Materials and Design 198 (2021) 109391 were analysed. After drying, the samples were gently ground by hand and then stored again in N 2 -filled desiccators at a relative humidity of 30%.  ...  Rentsch Materials and Design 198 (2021) 109391 Table 8 8 Calculated ion activity products (IAP) for M-A-S-H and NO 3 -hydrotalcite. }{OH − } 1.3 {H 2 O} 1.5 ; IAP (M 1 A 0.1 SH 1.75 ) = {Mg 2+ }{AlO  ... 
doi:10.1016/j.matdes.2020.109391 fatcat:cnanjk6j35akljirrwc2agbkfu

Insight into the Synthesis and Characterization of Organophosphorus-Based Bridged Triazine Compounds

Khalifah A. Salmeia, Antonia Neels, Dambarudhar Parida, Sandro Lehner, Daniel Rentsch, Sabyasachi Gaan
2019 Molecules  
In this article, we report the synthesis of 2,4,6-substituted s-triazine-based organophosphorus compounds via a two-step process, which enables their production in high yields, and with a high purity as solids. In the first step, a Michaelis–Arbuzov rearrangement of cyanuric chloride with triethyl phosphite afforded 2,4,6-trisdiethoxyphosphinyl-1,3,5-triazine (HEPT). Subsequently, the nucleophilic substitution reaction on the triazine carbon was achieved, owing to the electron-withdrawing
more » ... y of the phosphonate groups. This characteristic of HEPT facilitated its derivatization with bi-functional amines, producing novel P–C containing bridged triazine organophosphorus compounds. The molecular structures of all of the compounds were confirmed by NMR spectroscopy, CHN elemental analysis, and single crystal X-ray analysis. In the thermogravimetric analysis in an N2 environment, >33% char formation was observed for the bridged compounds. The chemical composition analysis of the char obtained under the oxidative thermal decomposition of the bridged compounds confirmed the presence of phosphorus- and nitrogen-enriched species, which indicate their function in the condensed phase. Comparatively, the detection of HPO and H–C≡P in the gas phase during the pyrolysis of the bridged compounds can act as a source for PO•, which is known for its gas phase flame inhibition reactions. The synergy of significant char formation and the generation of intermediates leading to PO• during pyrolysis makes these molecules promising flame-retardant additives.
doi:10.3390/molecules24142672 pmid:31340573 pmcid:PMC6681112 fatcat:lbmlqnmtczh5dhbjyqvvcfc2sa

Metabolites and dead-end products from the microbial oxidation of quaternary ammonium alcohols

Andres Kaech, Martina Hofer, Daniel Rentsch, Christian Schnider, Thomas Egli
2005 Biodegradation  
Methyl-triethanol-ammonium originates from the hydrolysis of the parent esterquat surfactant, which is used as softener in fabric care. The initial steps of the catabolism were investigated in cell-free extracts of the bacterial strain MM 1 able to grow with methyl-triethanol-ammonium as sole source of carbon, energy and nitrogen. The initial degradation of methyl-triethanol-ammonium is an enzymatically catalyzed reaction, located in the particulate fraction of strain MM 1. The oxygen dependent
more » ... reaction occurred also in presence of phenazine methosulfate as an alternative electron acceptor. As soon as one ethanol group of methyl-triethanol-ammonium was oxidized to the aldehyde, cyclic hemiacetals were formed by intramolecular cyclization. The third ethanol group of methyl-triethanol-ammonium was oxidized to the aldehyde and the carboxylic acid sequentially. The structurally related compounds dimethyl-diethanol-ammonium and choline were oxidized as well, whereas (±)-2,3-dihydroxypropyl-trimethyl-ammonium was not converted at all. The structures of the metabolites were established by 1D and 2D 1 H, 13 C and 14 N NMR spectroscopy and by capillary electrophoresis mass spectrometry. Abbreviations: CE-MS -capillary electrophoresis mass spectrometry; DM -dimethyl-diethanol-ammonium; HMBC -heteronuclear multiple bond correlation; HMQC -heteronuclear multiple quantum coherence; HSQC -heteronuclear single quantum coherence; INT -iodonitrotetrazolium chloride; MMmethyl-triethanol-ammonium; PF -particulate fraction of the cell-free extract; PMS -phenazine methosulfate; QAA -quaternary ammonium alcohol; TM -(±)-2,3-dihydroxypropyl-trimethyl-ammonium
doi:10.1007/s10532-004-5164-5 pmid:15865159 fatcat:i6moo4uadjhlxi4fkydqgvhgja

Shortwave infrared-absorbing squaraine dyes for all-organic optical upconversion devices

Karen Strassel, Wei-Hsu Hu, Sonja Osbild, Daniele Padula, Daniel Rentsch, Sergii Yakunin, Yevhen Shynkarenko, Maksym Kovalenko, Frank Nüesch, Roland Hany, Michael Bauer
2021 Science and Technology of Advanced Materials  
Shortwave infrared (SWIR) optical sensing and imaging are essential to an increasing number of next-generation applications in communications, process control or medical imaging. An all-organic SWIR upconversion device (OUC) consists of an organic SWIR sensitive photodetector (PD) and an organic light-emitting diode (OLED), connected in series. OUCs directly convert SWIR to visible photons, which potentially provides a low-cost alternative to the current inorganic compound-based SWIR imaging
more » ... hnology. For OUC applications, only few organic materials have been reported with peak absorption past 1000 nm and simultaneous small absorption in the visible. Here, we synthesized a series of thermally stable high-extinction coefficient donor-substituted benz[cd]indole-capped SWIR squaraine dyes. First, we coupled the phenyl-, carbazole-, and thienyl-substituted benz[cd]indoles with squaric acid (to obtain the SQ dye family). We then combined these donors with the dicyanomethylene-substituted squaraine acceptor unit, to obtain the dicyanomethylene-functionalized squaraine DCSQ family. In the solid state, the absorbance of all dyes extended considerably beyond 1100 nm. For the carbazole- and thienyl-substituted DCSQ dyes, even the peak absorptions in solution were in the SWIR, at 1008 nm and 1014 nm. We fabricated DCSQ PDs with an external photon-to-current efficiency over 30%. We then combined the PD with a fluorescent OLED and fabricated long-term stable OUCs with peak sensitivity at 1020 nm, extending to beyond 1200 nm. Our OUCs are characterized by a very low dark luminance (<10-2 cd m-2 at below 6 V) in the absence of SWIR light, and a low turn-on voltage of 2 V when SWIR light is present.
doi:10.1080/14686996.2021.1891842 pmid:33907525 pmcid:PMC8049466 fatcat:v3j4hh6iiveytfnghevqndqppm

Medikamentöse Behandlung des metastasierten Prostatakarzinoms

Richard Cathomas, Hans-Peter Schmid, Daniel Aebersold, Marie-Laure Amram, Dominik Berthold, Daniel Eberli, Silke Gillessen, Christophe Iselin, Patrice Jichlinski, Michael Müntener, Cyrill Rentsch, Niklaus Schäfer (+5 others)
2016 Swiss Medical Forum = Schweizerisches Medizin-Forum  
doi:10.4414/smf.2016.02607 fatcat:dw4dps4il5fdngcv5csdsycray

Improved breath alcohol analysis in patients with depressed consciousness

Annika Kaisdotter Andersson, Bertil Hök, Daniel Rentsch, Gernot Ruecker, Mikael Ekström
2010 Medical and Biological Engineering and Computing  
doi:10.1007/s11517-010-0655-5 pmid:20582483 fatcat:rnlffzrgx5fh3nlbiia66kkuay
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