Hibernation is a biological status during which hibernating animals acclimatize themselves to reduced energy consumption through extreme but governed decline in self-metabolism. The role of mitochondria (Mt) in metabolic suppression during hibernation has already been elaborated in different organs and species. Nonetheless, the concretely changing process of mitochondrial architecture and the mechanism underlying this transformation during hibernation remains unclear. Herein, the present study was aimed at clarifying the detailed alteration of mitochondrial morphology and its potential role in the Chinese soft-shelled turtle (Pelodiscus sinensis) during different stages of hibernation. Compared with the nonhibernation period, the mitochondrial architecture was changing from round to crescent, and lipid droplet (LD)/Mt interaction was enhanced during hibernation, as observed by transmission electron microscopy (TEM). Further ultrastructural analysis uncovered that mitochondrial fusion was promptly accelerated in the early stage of hibernation, followed by mitochondrial fission in the middle stage, and mitophagy was boosted in the late stage. Moreover, gene and protein expression related to mitochondrial fusion, fission, and mitophagy accorded closely with the mitochondrial ultrastructural changes in different stages of hibernation. Taken together, our results clarified that the transformation of mitochondrial architecture and mitochondrial dynamics are of vital importance in maintaining internal environment homeostasis of Pelodiscus sinensis.

The blood-brain barrier (BBB) is an important internal barrier. Herein, the electron microscope examination of duck BBB was performed during the brain development. Meanwhile, the genes/proteins of tight junctions (TJs) including zonula occludens-1, occludin, and claudin-5 in the duck brain were detected by Q-PCR and immunohistochemistry. The results showed the density of capillaries in the brain gradually increased during the embryonic period. The generation of the BBB and the specialization of its components occurred mainly in the embryonic stage. During this period, the endothelial cells (ECs) became thinner and pinocytic vesicles decreased; the TJs between EC membranes became longer and more electron-dense; the basement membrane surrounding ECs and pericytes gradually thickened; and the astrocyte foot processes appeared to wrap around the vessels. By the day of hatching (P1), the whole set of duck BBB structures was completely assembled and gradually improved in the subsequent growth process. Interestingly, compared with the cerebrum and cerebellum, the maturity level of the midbrain BBB was earlier seen during the embryonic stage. The expression of TJs increased during the embryonic period and remained stable by post-hatching. The study systematically investigated the histochemical and ultrastructural features of duck BBB during development and explored the corresponding relationship between structure and function.

A simple and novel method was developed for efficient synthesis of aligned multiwalled carbon nanotubes (CNTs) in methanol and ethanol under normal pressure. The CNTs' alignment and structures were investigated using Raman scattering and x-ray diffraction spectroscopy. A unique kind of coupled CNT was synthesized in which one rotated to the left and one rotated to the right. Chains periodically bridged the coupled CNTs. The growth mechanism of the CNTs within organic liquid is proposed to be a catalytic process at the Fe film surface in a dynamic and thermal nonequilibrium condition in organic liquids.

Effects of hydrogen sulfide on the structure of carbon nanotubes (CNTs) were studied using high-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS). The CNTs were synthesized with an iron thin-film catalyst by microwave plasma-assisted CVD on the diamond substrate. The HRTEM images revealed that essentially all of the CNTs obtained in this study were multiwall (MWCNT). The addition of H2S resulted in nanotubes with split skins as cornhusks and/or frills. Electron energy loss spectra of the cornhusks indicated that they consist of sp2, sp3 and amorphous carbon phase. The spectra revealed that the sp3 to sp2 ratio at the points where cornhusks divide from the main stem was more than that at the edge of the cornhusks. No evidence of sulfur incorporation into the MWCNTs grown with the H2S addition was found. We speculate that the chemical nature of sulfur on the CNT growth yields such anomalous structure.

The tendency of graphite-diamond transformation assisted by nonmetallic catalysts of carbonates, sulfates, or phosphorus under high pressure and high temperature has been investigated by calculating the activation energy and transformation probability of the carbon atoms over a potential barrier. It was found that the activation energy is highly sensitive to the catalyst chosen. The value of activation energy in the systems of graphite-carbonates, graphite-phosphorus, and graphite-sulfate are 130.71 × 103, 206.03 × 103, and 221 × 103 J/mol, respectively. If fd stands for the probability of the transformation from graphite to diamond, the probability sequence of graphite-diamond transformation in different systems was put forward: fd(gr.-carbonate) > fd(gr.-phosphorus). fd(gr.-sulfate).

The current-voltage (I-V) characteristics and time-dependence photoconductivity of the undoped and B-doped diamond films (DF's) before and after annealing were investigated. The boron and hydrogen concentration in diamond films were measured by means of nuclear reaction analysis (NRA) and the elastic-recoil detection (ERD) technique, respectively. The results show that induced boron atoms and hydrogen atoms affect the electrical and photocoaductive properties of diamond films. During the annealing process, B concentration kept even, but H content decreased. For undoped diamond films, the escaping of H atoms has great effects on the electrical characteristics, but for B-doped samples, this effect decreases with the increase of B concentration.

Covalent carbon nitride films have been synthesized by laser ablation and ion-beam coprocessing. Different laser ablations give different ablated graphite plasma. Beta- C3N4 polycrystalline has been found in the deposited films. Under laser energy of 50 mJ per pulse, the adoption of 532 nm laser used for ablation of graphite is proposed for the purpose of production of good carbon nitride films. The C-N crystal structures can be improved by followed ion-beam processing.

Crystalline carbon nitride films have been synthesized in a rf plasma assisted hot filament chemical vapor deposition system. Large crystalline grains up to ∼10 μm in size as well as film-like regions are observed in the morphology of the films. β-C3N4 with two groups of lattice parameters ( one is consistent with the theoretical value and the other is 3% smaller) in the deposited films on polycrystalline Ni substrate has been revealed by x-ray diffraction spectrum (XRD). No Raman shift peaks have been found evidently by Raman scattering measurement, but some presently unknown diffraction peaks appeared in the XRD spectrum. It is proposed that there are possible unknown structures of crystalline C-N in the films. Heteroepitaxial growth of crystalline β-C3N4 has also been tried via a buffer layer of α-SiC on Si (100) substrate. The XRD pattern of a film show that there are only two main peaks at 2.79 Å and 1.87 Å corresponding to the (200) and (300) crystalline planes of the theoretical β-C3N4 The two main peaks indicate heteroepitaxial growth along the (100) direction of β-C3N4.

An attempt to unify the growth mechanisms and conditions for diamond formation is developed via the growth probability calculated by a barrier model between the two phases. From the distribution law of the equal growth probability lines plotted in a pressure-temperature (P-T) diagram, five regions of different growth methods and mechanisms were reasonably delineated. Many experimental results can be generalized and explained by our theory, and the unity of diamond growth mechanism was discussed over the wide region of the P-T condition.