Monosubstituted Doublet Sn(I) Radical Featuring Substantial Unquenched Orbital Angular Momentum.

Due to their intrinsic high reactivity, isolation of heavier analogues of carbynes remains a great challenge. Here, we report the synthesis and characterization of a neutral monosubstituted Sn(I) radical (2) supported by a sterically hindered hydrindacene ligand, which represents the first tin analogue of a free carbyne. Different from all Sn(I/III) species reported thus far, the presence of a sole Sn-C σ bond in 2 renders the remaining two Sn 5p orbitals energetically almost degenerate, of which one is singly occupied and the other is empty. Consequently, its S = 1/2 ground state possesses two-fold orbital pseudo-degeneracy and substantial unquenched orbital angular momentum, as evidenced by one component of its g matrix (1.957, 1.896, and 1.578) being considerably less than 2. Consistent with this unique electronic structure, 2 can bind to an N-heterocyclic carbene to afford a neutral two-coordinate Sn(I) radical and initiate a one-electron transfer to benzophenone to furnish a Sn(II)-ketyl radical anion adduct. As a manifestation of its Sn-centered radical nature, 2 reacts with diphenyl diselenide and p-benzoquinone to form Sn-S and Sn-O bonds, respectively.

Transformation of Viral Light Particles into Near-Infrared Fluorescence Quantum Dot-Labeled Active Tumor-Targeting Nanovectors for Drug Delivery.

Nanosized oncolytic viral light particles (L-particles), separated from progeny virions, are composed of envelopes and several tegument proteins of viruses, free of nucleocapsids. The noninfectious L-particles experience the same internalization process as mature oncolytic virions, which exhibits great potential to act as targeted therapeutic platforms. However, the clinical applications of L-particle-based theranostic platforms are rare due to the lack of effective methods to transform L-particles into nanovectors. Herein, a convenient and mild strategy has been developed to transform L-particles into near-infrared (NIR) fluorescence Ag2Se quantum dot (QD)-labeled active tumor-targeting nanovectors for real-time in situ imaging and drug delivery. Utilizing the electroporation technique, L-particles can be labeled with ultrasmall water-dispersible NIR fluorescence Ag2Se QDs with a labeling efficiency of ca. 85% and loaded with antitumor drug with a loading efficiency of ca. 87%. Meanwhile, by harnessing the infection mechanism of viruses, viral L-particles are able to recognize and enter tumor cells without further modification. In sum, a trackable and actively tumor-targeted theranostics nanovector can be obtained efficiently and simultaneously. Such multifunctional nanovectors transformed from viral L-particles have exhibited excellent properties of active tumor-targeting, in vivo tumor imaging, and antitumor efficacy, which opens a new window for the development of natural therapeutic nanoplatforms.

An isolable germylyne radical with a one-coordinate germanium atom.

Carbynes (R-[Formula: see text]), species that bear a monovalent carbon atom with three non-bonding valence electrons, are important intermediates and potentially useful in organic synthetic chemistry. However, free species of the type R-[Formula: see text] of any group 14 element (E) have eluded isolation in the condensed phase due to their high reactivity. Here we report the isolation, characterization and reactivity of a crystalline germylyne radical by using a sterically hindered hydrindacene ligand. The germylyne radical bears an essentially one-coordinate germanium atom as shown by single-crystal X-ray diffraction analysis. Electron paramagnetic resonance spectroscopic studies and theoretical calculations show that the germylyne radical features a doublet ground state, and the three non-bonding valence electrons at the germanium atom contribute to the lone pair of electrons as the highest occupied molecular orbital-3 and one unpaired electron as the singly occupied molecular orbital.

Characterization of the complete chloroplast genome of Rumex nepalensis (Polygonaceae).

Rumex nepalensis (Polygonaceae) is a fairly common perennial herb of high altitudes. In this study, we determined the complete chloroplast genome (plastome) of R. nepalensis with genome-skimming method. The complete plastome of R. nepalensis was 159,110 bp in length with a quadripartite structure, including a large single-copy region of 84,810 bp, a small single-copy region of 13,044 bp, and a pair of inverted repeats regions of 30,628 bp. The overall guanine-cytosine (GC) content was 37.5%. A total of 112 unique genes was annotated in this plastome, including 78 protein-coding genes, 30 tRNA genes, and four rRNA genes. In the ML tree, R. nepalensis was sister to R. crispus, and Rumex was sister to a clade comprising Rheum and Oxyria within Polygonaceae famliy.

[Effect of bone grafting on the repair of distal alveolar bone defect of the second molar after extraction of mandibular impacted third molar].

PURPOSE: To observe the effect of bone grafting during the extraction of mandibular third molar on repair of distal alveolar bone defect distal to the second molar. METHODS: The risks of the distal alveolar bone defect in the second molar were estimated after removal of the impacted teeth according to the position of the third molar and second molar before operation. It was divided into three groups: low risk group, medium risk group and high risk group. The medium risk group and high risk group were further divided into bone graft subgroup (group A) and non-bone graft subgroup (group B). There were 36 cases in group A and 45 cases in group B. Postoperative re-examination indicators included subjective perception of the patients, depth of probing and height of alveolar bone in the distal molar of the second molar by X-ray examination. The data were analyzed with SPSS 19.0 software package. RESULTS: Six months after operation, in mediun risk group, 0 cases in group A had subjective feelings of cold and heat stimulation; in group B, the number was 6 cases, the difference was significant (P<0.05). Distal periodontal probing depth of the second molar was (2.93±0.34) mm in group A and (2.95±0.50) mm in group B. There was no significant difference between 2 groups (P=0.931). X-ray examination of the alveolar bone height increment of the second molar Δh: (3.31±1.02) mm in group A, (3.10±1.72) mm in group B, the difference was not significant (P=0.794). In high risk group, 4 cases in group A had subjective feelings of cold and heat stimulation; in group B, the number was 10 cases,the difference was significant (P<0.05). Distal periodontal probing depth of the second molar was (3.08±0.37) mm in group A and (3.24±0.41) mm in group B. There was no significant difference between 2 groups(P=0.931). X-ray examination of the alveolar bone height increment of the second molar Δh: (5.21±1.79) mm in group A, (2.99±2.42) mm in group B, the difference was significant (P<0.05). CONCLUSIONS: Risk classification of the second molar distal bone defects after extraction of the impacted teeth is essential, which is helpful to determine whether bone grafting is needed during operation. Autologous bone mixed with Bio-Oss artificial bone powder can promote recovery of the alveolar bone height of the second molar, especially in high risk group, and discomfort caused by exposure can be reduced.

Activation of phosphatidylinositol 3-kinase and protein kinase B/Akt in dorsal root ganglia and spinal cord contributes to the neuropathic pain induced by spinal nerve ligation in rats.

Several lines of evidence indicate that phosphatidylinositol 3-kinase (PI3K) and PI3K-protein kinase B/Akt (PKB/Akt) signal pathway mediate the pain hypersensitivity induced by intradermal injection of capsaicin or nerve growth factor. However, the role of PI3K and PI3K-PKB/Akt signal pathway activation in neuropathic pain is still unclear. Using L5 spinal nerve ligation (L5 SNL) and immunohistochemistry, we found that the numbers of phospho-PKB/Akt-immunoreactive (p-PKB/Akt IR) positive neurons were significantly increased in ipsilateral L5 dorsal root ganglia (DRG) and adjacent L4 DRG started at 12 h after surgery and maintained to the 3rd day. Meanwhile, L5 SNL also induced an increased expression of p-PKB/Akt in ipsilateral L5 spinal dorsal horn. Double immunofluorescence staining showed that p-PKB/Akt expressed entirely in DRG neurons, especially in IB4-positive neurons. Intrathecal injection of PI3K inhibitor wortmannin or LY294002 and PKB/Akt inhibitor Akt inhibitor IV or (-)-Deguelin, started before L5 SNL, reduced the behavioral signs of neuropathic pain. Intraperitoneal injection of wortmannin or (-)-Deguelin as above also reduced the pain hypersensitivity. Post-treatment with wortmannin, started at the 1st day or the 3rd day after L5 SNL, decreased abnormal pain behaviors. Whereas the inhibitory effect of Akt inhibitor IV on established neuropathic pain was observed only in those rats that received the drug treatment started at the 1st day. Immunohistochemistry revealed that intrathecal injection of wortmannin significantly inhibited the activation of PKB/Akt in L5 DRG and L5 spinal cord. The data suggested that PI3K and PI3K-PKB/Akt signal pathway activation might contribute to the development of neuropathic pain.