King of the spins is provided by the mixed‐valent Mn19 aggregate as reported by A. K. Powell et al. in their Communication on page 4926 ff. The use of bridging azido ligands leads to a completely ferromagnetically coupled system with a record ground spin state of 83/2. This remarkable molecule has been investigated and characterized by scientists from three laboratories working together in the European Network of Excellence “MAGMANet”, the logo of which provides the background to the cover picture.
Single-walled carbon nanotubes (SWNTs) covalently modified with large porphyrin molecules have been
prepared to construct photoelectrochemical devices with nanostructured SnO2 electrodes on which the
multiporphyrin-linked SWNTs are deposited electrophoretically. The film of the porphyrin-linked SWNTs
on the nanostructured SnO2 electrode exhibited an incident photon-to-photocurrent efficiency as high as 4.9%
under an applied potential of 0.08 V vs SCE. The more uniform film and moderate photocurrent generation
in the porphyrin-linked SWNT devices can be rationalized by the exfoliation abilities of the bulky porphyrins
that yield large steric hindrance around the SWNTs. Direct electron injection from the excited states of the
SWNTs to the conduction band of the SnO2 electrode is responsible for the photocurrent generation. Despite
the efficient quenching of the porphyrin-excited singlet state by the SWNTs in the porphyrin-linked SWNTs,
the photocurrent action spectra revealed that the excitation of the porphyrin moieties makes no contribution
to the photocurrent generation. The evolution of an exciplex between the porphyrin-excited singlet state and
the SWNTs and the subsequent rapid decay to the ground state without generating the charge-separated state
is proposed to explain the unusual photoelectrochemical behavior. The results obtained here will provide
valuable information on the design of SWNT-based photoelectrochemical devices.
Sidewalls of acid-treated, shortened single-walled carbon nanotubes (SWNTs) with long alkyl chains at the open ends and defect sites have been functionalized by Bingel reaction to examine the structures and spectroscopic properties in detail for the first time. The microwave-assisted Bingel reaction has been successfully applied to the sidewall functionalization of which the reaction rate is ca. 50 times faster than that under the conventional conditions. The degree of the sidewall functionalization (one diester unit per 75-300 carbon atoms of SWNTs) was found to be controllable by changing the output power of the microwave under the same temperature. Atomic force microscopy and transmission electron microscopy showed the progressive exfoliation of the SWNT bundles by the double chemical modification. Resonant Raman and UV-vis-NIR absorption spectroscopies revealed that the electronic properties of SWNT are largely retained after a significant degree of sidewall modification by the Bingel reaction without apparent selective reactivity for metallic and semiconducting SWNTs. This is in remarkable contrast with the conventional sidewall functionalization of SWNTs leading to the loss of their electronic properties (one functional group per 10-100 carbon atoms on the sidewall). Thus, our covalent functionalization methodology can provide SWNT materials with both excellent solubility and inherent electronic properties which are highly desirable in solution-phase processing for the fabrication of SWNT-based molecular devices.
The International Society for Stem Cell Research has updated its Guidelines for Stem Cell Research and Clinical Translation in order to address advances in stem cell science and other relevant fields, together with the associated ethical, social, and policy issues that have arisen since the last update in 2016. While growing to encompass the evolving science, clinical applications of stem cells, and the increasingly complex implications of stem cell research for society, the basic principles underlying the Guidelines remain unchanged, and they will continue to serve as the standard for the field and as a resource for scientists, regulators, funders, physicians,
This study examined the decision-making processes of donors in adult-to-adult living donor liver transplantation. Twenty-two donors were interviewed using a semi-structured format. Interview contents were transcribed verbatim and analyzed qualitatively using grounded theory. A decision-making model was developed consisting of 5 stages: (1) recognition, (2) digestion, (3) decision-making, (4) reinforcement, and (5) resolution. The second and the third stages described donors' experiences of "reaching a decision"; the fourth and fifth stages described those of "facing transplantation." The central theme of this model was "having no choice," which consisted of 4 codes: (1) priority of life, (2) only LDLT, (3) for family, and (4) only me. In conclusion, this model can help health care professionals to understand the donor experience and, based on that understanding, to provide sufficient support to the donor. Liver Transpl 12: 768-774, 2006.
Recently, the use of three-dimensional neural tissues cultured in vitro and called "cerebral organoids" has advanced recapitulation of neural development and disease modeling studies. Along with such advances, cerebral organoid research, and associated concerns call for the elucidation of two points: (1) how cerebral organoid research is currently progressing and the future directions it is likely to take, especially in functional assessment of organoids, and (2) how we should solve ethical issues of possible consciousness in cerebral organoid research. This paper aims first to explore these two issues, and then to present implications and prospects for future cerebral organoid research.
BackgroundPrevious studies have found that the decision-making process for stored unused frozen embryos involves much emotional burden influenced by socio-cultural factors. This study aims to ascertain how Japanese patients make a decision on the fate of their frozen embryos: whether to continue storage discard or donate to research.MethodsTen Japanese women who continued storage, 5 who discarded and 16 who donated to research were recruited from our infertility clinic. Tape-recorded interviews were transcribed and analyzed for emergent themes.ResultsA model of patients’ decision-making processes for the fate of frozen embryos was developed, with a common emergent theme, “coming to terms with infertility” resulting in either acceptance or postponing acceptance of their infertility. The model consisted of 5 steps: 1) the embryo-transfer moratorium was sustained, 2) the “Mottainai”- embryo and having another child were considered; 3) cost reasonability was taken into account; 4) partner’s opinion was confirmed to finally decide whether to continue or discontinue storage. Those discontinuing, then contemplated 5): the effect of donation. Great emotional conflict was expressed in the theme, steps 2, 4, and 5.ConclusionsPatients’ 5 step decision-making process for the fate of frozen embryos was profoundly affected by various Japanese cultural values and moral standards. At the end of their decision, patients used culturally inherent values and standards to come to terms with their infertility. While there is much philosophical discussion on the moral status of the embryo worldwide, this study, with actual views of patients who own them, will make a significant contribution to empirical ethics from the practical viewpoint.
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