Controlling the Intrinsic Josephson Junction Number in a Bi2Sr2CaCu2O8+δ\mathbf{Bi_2Sr_2CaCu_2O_{8+\delta}} Mesa

In fabricating $\mathrm{Bi_2Sr_2CaCu_2O_{8+\delta}}$ intrinsic Josephson junctions in 4-terminal mesa structures, we modify the conventional fabrication process by markedly reducing the etching rates of argon ion milling. As a result, the junction number in a stack can be controlled quite satisfactorily as long as we carefully adjust those factors such as the etching time and the thickness of the evaporated layers. The error in the junction number is within $\pm 1$. By additional ion etching if necessary, we can controllably decrease the junction number to a rather small value, and even a single intrinsic Josephson junction can be produced.Comment: to bu published in Jpn. J. Appl. Phys., 43(7A) 200

Expression of hydrogen sulfide, hydrogen-sulfide synthase and cyclooxygenase-2, and their mechanisms of action in amniotic tissues

Purpose: To investigate the expressions of cystathionine β-synthase (CBS), cystathionine γ - lyase (CSE) and cyclooxygenase - 2 (COX - 2) and their relationships with premature delivery in amniotic tissues.Methods: Parturients were divided into three groups: 40 preterm-labor parturients (PTL group), 28 term-labor parturients (TL group), and 28 term non-labor parturients (TNL group). Changes in expressions of CBS, CSE and COX-2 were determined by Western blot (WB) in amniotic tissues of parturients in the three groups. The expression of COX - 2 was determined after the amniotic tissues of parturients in the TNL group were cultured in vitro and processed by exogenous hydrogen-sulfide (H2S).Results: The expression level of COX - 2 was significantly lower in the TNL group, when compared with the PTL and TL groups (p < 0.05). The  expression of CBS was increased in the order PTL > TL > TNL, with TNL group having the highest level, and there were significant differences in CBS expressions among the three groups (p < 0.05).Conclusion: These results suggest that when the expressions of CBS and CSE are down-regulated, the decreased H2S synthesis promotes the overexpression of COX - 2 by NF - kB signaling pathway, causing increased prostaglandin synthesis which results in premature delivery.Keywords: Cystathionine β - synthase, Cystathionine γ - lyase,  Cyclooxygenase - 2; Amniotic tissues; Preterm labo

Enhanced excitability of small dorsal root ganglion neurons in rats with bone cancer pain

<p>Abstract</p> <p>Background</p> <p>Primary and metastatic cancers that affect bone are frequently associated with severe and intractable pain. The mechanisms underlying the development of bone cancer pain are largely unknown. The aim of this study was to determine whether enhanced excitability of primary sensory neurons contributed to peripheral sensitization and tumor-induced hyperalgesia during cancer condition. In this study, using techniques of whole-cell patch-clamp recording associated with immunofluorescent staining, single-cell reverse-transcriptase PCR and behavioral test, we investigated whether the intrinsic membrane properties and the excitability of small-sized dorsal root ganglion (DRG) neurons altered in a rat model of bone cancer pain, and whether suppression of DRG neurons activity inhibited the bone cancer-induced pain.</p> <p>Results</p> <p>Our present study showed that implantation of MRMT-1 tumor cells into the tibial canal in rats produced significant mechanical and thermal hyperalgesia in the ipsilateral hind paw. Moreover, implantation of tumor cells provoked spontaneous discharges and tonic excitatory discharges evoked by a depolarizing current pulse in small-sized DRG neurons. In line with these findings, alterations in intrinsic membrane properties that reflect the enhanced neuronal excitability were observed in small DRG neurons in bone cancer rats, of which including: 1) depolarized resting membrane potential (RMP); 2) decreased input resistance (R_in); 3) a marked reduction in current threshold (CT) and voltage threshold (TP) of action potential (AP); 4) a dramatic decrease in amplitude, overshot, and duration of evoked action potentials as well as in amplitude and duration of afterhyperpolarization (AHP); and 5) a significant increase in the firing frequency of evoked action potentials. Here, the decreased AP threshold and increased firing frequency of evoked action potentials implicate the occurrence of hyperexcitability in small-sized DRG neurons in bone cancer rats. In addiotion, immunofluorescent staining and single-cell reverse-transcriptase PCR revealed that in isolated small DRG neurons, most neurons were IB4-positive, or expressed TRPV1 or CGRP, indicating that most recorded small DRG neurons were nociceptive neurons. Finally, using in vivo behavioral test, we found that blockade of DRG neurons activity by TTX inhibited the tumor-evoked mechanical allodynia and thermal hyperalgesia in bone cancer rats, implicating that the enhanced excitability of primary sensory neurons underlied the development of bone cancer pain.</p> <p>Conclusions</p> <p>Our present results suggest that implantation of tumor cells into the tibial canal in rats induces an enhanced excitability of small-sized DRG neurons that is probably as results of alterations in intrinsic electrogenic properties of these neurons. Therefore, alterations in intrinsic membrane properties associated with the hyperexcitability of primary sensory neurons likely contribute to the peripheral sensitization and tumor-induced hyperalgesia under cancer condition.</p

Diaqua­bis­(1-methyl-1H-imidazole-κN 3)bis­[2-(naphthalen-1-yl)acetato-κO]cobalt(II)

In the title compound, [Co(C12H9O2)2(C4H6N2)2(H2O)2], the CoII ion is located on an inversion centre and displays a distorted octa­hedral coordination geometry. Two O atoms from two water mol­ecules and two carboxyl­ate O atoms from two 2-(naphthalen-1-yl)acetate ligands are in the equatorial plane and two N atoms from two 1-methyl-1H-imidazole ligands are in the axial positions. The structure is stabilized by intra­molecular O—H⋯O hydrogen bonds. Inter­molecular O—H⋯O hydrogen bonds link the complex mol­ecules into chains along [100]

Bis­(2-methyl-1H-imidazole-κN 3)bis[2-(naphthalen-2-yl)acetato-κO]copper(II)

In the crystal structure of the title compound, [Cu(C12H9O2)2(C4H6N2)2], the Cu(II) cations are square-planar coordinated by two 1-naphthyl­acetate anions and two 2-methyl-imidazole ligands into discrete complexes that are located on centres of inversion. These complexes are linked into chains parallel to [010] by inter­molecular N—H⋯O hydrogen bonding between the N—H H atom of the 2-methyl-imidazole ligands and the carboxyl­ate O atoms that are not involved in metal coordination

Pyrrolidin-1-ium 2-(naphthalen-1-yl)acetate–2-(naphthalen-1-yl)acetic acid (1/1)

In the title compound, C4H10N+·C12H9O2 −·C12H10O2, the pyrrolidine ring adopts an envelope conformation and the dihedral angle between the planes of the two naphthalene ring systems is 8.34 (10)°. The crystal structure is stabilized by O—H⋯O and N—H⋯O hydrogen bonds

Digit-only sauropod pes trackways from China - evidence of swimming or a preservational phenomenon?

For more than 70 years unusual sauropod trackways have played a pivotal role in debates about the swimming ability of sauropods. Most claims that sauropods could swim have been based on manus-only or manus-dominated trackways. However none of these incomplete trackways has been entirely convincing, and most have proved to be taphonomic artifacts, either undertracks or the result of differential depth of penetration of manus and pes tracks, but otherwise showed the typical pattern of normal walking trackways. Here we report an assemblage of unusual sauropod tracks from the Lower Cretaceous Hekou Group of Gansu Province, northern China, characterized by the preservation of only the pes claw traces, that we interpret as having been left by walking, not buoyant or swimming, individuals. They are interpreted as the result of animals moving on a soft mud-silt substrate, projecting their claws deeply to register their traces on an underlying sand layer where they gained more grip during progression. Other sauropod walking trackways on the same surface with both pes and manus traces preserved, were probably left earlier on relatively firm substrates that predated the deposition of soft mud and silt . Presently, there is no convincing evidence of swimming sauropods from their trackways, which is not to say that sauropods did not swim at all

Bis(1H-benzimidazole-κN 3)bis­[2-(naphthalen-1-yl)acetato-κ2 O,O′]nickel(II) monohydrate

In the title compound, [Ni(C12H9O2)2(C7H6N2)2]·H2O, The NiII cation is located on a twofold rotation axis and is six-coordinated in a distorted NiN2O4 octa­hedral geometry. The asymmetric unit consists of a nickel(II) ion, one 2-(naphthalen-1-yl)acetate anion, a neutral benzotriazole ligand and one half of a lattice water mol­ecule. The crystal packing is stabilized by O—H⋯O and N—H⋯O hydrogen bonds. The title compound is isotypic with its CdII analogue

Bis(1-methyl-1H-imidazole-κN 3)bis­[2-(naphthalen-1-yl)acetato-κO]copper(II) monohydrate

In the crystal structure of the title compound, [Cu(C12H9O2)2(C4H6N2)2]·H2O, the CuII atom is coordinated by two 2-(naphthalen-1-yl)acetate anions and two 1-methyl­imidazole ligands, giving monomeric complexes with a square-planar coordination environment. Two complex mol­ecules and two water mol­ecules form a centrosymmetric ring system via O—H⋯O hydrogen bonds