Fluctuating light induces a significant photoinhibition of photosystem I in maize.

In nature, light intensity usually fluctuates and a sudden shade-sun transition can induce photodamage to photosystem I (PSI) in many angiosperms. Photosynthetic regulation in fluctuating light (FL) has been studied extensively in C3 plants; however, little is known about how C4 plants cope FL to prevent PSI photoinhibition. We here compared photosynthetic responses to FL between maize (Zea mays, C4) and tomato (Solanum lycopersicum, C3) grown under full sunlight. Maize leaves had significantly higher cyclic electron flow (CEF) activity and lower photorespiration activity than tomato. Upon a sudden shade-sun transition, maize showed a significant stronger transient PSI over-reduction than tomato, resulting in a significant greater PSI photoinhibition in maize after FL treatment. During the first seconds upon shade-sun transition, CEF was stimulated in maize at a much higher extent than tomato, favoring the rapid formation of trans-thylakoid proton gradient (ΔpH), which was helped by a transient down-regulation of chloroplast ATP synthase activity. Therefore, modulation of ΔpH by regulation of CEF and chloroplast ATP synthase adjusted PSI redox state at donor side, which partially compensated for the deficiency of photorespiration. We propose that C4 plants use different photosynthetic strategies for coping with FL as compared with C3 plants.

Scrotum solitary fibrous tumor: A case report and review of literature.

BACKGROUND: A solitary fibrous tumor (SFT) is a rare clinical tumor, often manifesting as solitary nodules. It is a rare condition that occurs in the scrotum. Currently, no study has reported this condition. CASE SUMMARY: We reported a case of an SFT in a 77-year-old man, and discuss its diagnosis, differential diagnosis, and treatment. Clinical and histopathological features, as well as the EnVision 2-step method, were used to diagnosis the SFT. The results of imaging tests and surgery indicated that the SFT was located in the right scrotum with 2 connected tumor nodules and a clear perimeter. The larger one was 11.0 cm × 9.3 cm × 8.1 cm, and the smaller one was 3.1 cm × 2.0 cm × 2.0 cm. Pathological results indicated that in both tumor nodules, tumor cells were spindle-shaped with unclear cell boundaries. The nucleus was vacuolated with mild to moderate atypia. In the larger tumor nodule, there were many thin-walled blood vessels with vasodilation or branching. In the smaller tumor nodule, rich blood vessels were found, mostly with fibrous degeneration of the thick walls of blood vessels, and more collagen-like tissue in the interstitial layers. Immunohistochemical results demonstrated diffuse, strongly positive expression of CD34, CD99, Vim, and Bcl-2 markers. The expression of the new fusion gene, NAB2-STAT6, as an alternative tool specifically confirmed the diagnosis of SFT. This patient underwent lump resection without further treatment. The patient is alive after 18-month follow-up. CONCLUSION: This case was diagnosed as a SFT according to its histopathological features, immunophenotype. The patient is still alive at 18 months follow-up after the lump resection.

Poly[[sesqui[mu2-1,4-bis(imidazol-1-ylmethyl)benzene-kappa(2)N:N'](carbonato-kappa(2)O,O')copper(II)] 1,4-bis(imidazol-1-ylmethyl)benzene hemisolvate pentahydrate].

The asymmetric unit of the title compound, {[Cu(CO(3))(C(14)H(14)N(4))(1.5)] x 0.5 C(14)H(14)N(4) x 5 H(2)O}(n), contains one Cu(II) cation in a slightly distorted square-pyramidal coordination environment, one CO(3)(2-) anion, one full and two half 1,4-bis(imidazol-1-ylmethyl)benzene (bix) ligands, one half-molecule of which is uncoordinated, and five uncoordinated water molecules. One of the coordinated bix ligands and the uncoordinated bix molecule are situated about centers of symmetry, located at the centers of the benzene rings. The coordinated bix ligands link the copper(II) ions into a [Cu(bix)(1.5)](n) molecular ladder. These molecular ladders do not form interpenetrated ladders but are arranged in an ABAB parallel terrace, i.e. with the ladders arranged one above another, with sequence A translated with respect to B by 8 A. To best of our knowledge, this arrangement has not been observed in any of the molecular ladder frameworks synthesized to date. The coordination environment of the Cu(II) atom is completed by two O atoms of the CO(3)(2-) anion. The framework is further strengthened by extensive O-H...O and O-H...N hydrogen bonds involving the water molecules, the O atoms of the CO(3)(2-) anion and the N atoms of the bix ligands. This study describes the first example of a molecular ladder coordination polymer based on bix and therefore demonstrates further the usefulness of bix as a versatile multidentate ligand for constructing coordination polymers with interesting architectures.