Structural, vibrational and electronic properties of nitrogen-rich 2,4,6-triazide-1,3,5-triazine under high pressure.

CONTEXT AND RESULTS: 2,4,6-triazide-1,3,5-triazine (TAT) has received widespread attention for its great potential to synthesize or convert to nitrogen-rich high energy density materials (HEDMs). The TAT structure alteration in the compression process up to 30 GPa has characteristics as follows: (a) [N3] groups straighten; (b) [N3] groups gather toward the six-membered C-N heterocycles. At about 5 GPa, Raman peak split at 700 cm-1 was observed both in calculation and in-situ Raman experiment, which is caused by pressure-induced intramolecular stress. Besides, the broad band of the amorphous two-dimensional C=N network (centered at 1630 cm-1) occurred at about 12 GPa. Meantime, the study on electronic features suggests the pressure-induced deformation in TAT molecular structure cause the discontinuous change of band gap at about 4.5 GPa and 8.0 GPa, respectively. COMPUTATIONAL AND THEORETICAL TECHNIQUES: The static compression process of TAT was explored in the range of 0-30 GPa by using dispersion corrected density functional theory (DFT-D) calculations combined with in-situ Raman experiment. The GGA/PBE+G06 method that has less errors than other calculation methods was used to predict the geometry structure, vibrational properties and electronic structure of TAT under pressure.

Bracovirus-mediated innexin hemichannel closure in cell disassembly.

Cell-cell communication is necessary for cellular immune response. Hemichannel closure disrupts communication between intracellular and extracellular environments during polydnavirus-induced immunosuppression in invertebrates. However, the effects of hemichannel closure on cellular immune response are unclear. Here, we examined apoptotic body formation triggered by hemichannel closure in hemocytes of Spodoptera litura infected with bracovirus from the parasitic wasp, Microplitis bicoloratus. We showed that Microplitis bicoloratus bracovirus (MbBV) induced apoptotic cell disassembly, accompanied by hemichannel closure. Hemocyte apoptotic body formation was caused by the dysregulation of the innexins (Inxs), Inx1, Inx2, Inx3, and Inx4, during the MbBV-mediated inhibition of pI3K/AKT signaling and activation of caspase-3, which cleaved gap junction Inx proteins. Our results showed that hemichannel opening or closure in response to various stimuli, which induces the modulation of Inx levels, could inhibit or activate apoptotic body formation, respectively. Therefore, the "hemichannel open and close" model may regulate the cellular immune response.

[Analysis of Gene Mutation Types of Thalassemia in Quanzhou Area of Fujian Province in China].

OBJECTIVE: To investigate the gene mutation types and gene carrying rate of common thalassemia in patients with thalassemia in Quanzhou, and to analyze its molecular epidemiological characteristics in Quanzhou. METHODS: 546 patients with thalassemia diagnosed at the first hospital of Quanzhou from January 2017 to October 2018 were collected and retrospectively analyzed for their types of mutations and carrier rates. RESULTS: Among the 4226 samples submitted, 546 positive samples were detected, the total carrying rate of the thalassaemia genes was 12.92%; the carrier rate of α-thalassemia was 8.16%; the carrier rate of ß-thalassemia was 4.76%; There were more α-thalassemia missing patients than non-deleted patients. The Southeast Asian deletion type (--SEA /αα) was the most common one, with a composition ratio of 68.98%, which was followed by 22.61% (-α3.7/αα), 2.61% (αWSα/αα), and 2.32% (ααCS/αα), 2.32% (αQSα/αα), 1.16% (-α4.2/αα); 9 types of ß-thalassemia gene mutations were detected. The most common three mutations were IVSII-654 (C→T, 42.29%), CD41-42 (-TTCT, 33.83%), CD17 (A→T, 12.94%). 2 cases of --THAI/αα , 1 case of αα/αααanti3.7 and 1 case of HKαα were detected. CONCLUSION: This study shows that the gene carrying rate of thalassemia in Quanzhou is high and has diversity, which can provide some reference for the prevention and control of thalassemia in Quanzhou.

KMT5A promotes metastasis of clear cell renal cell carcinoma through reducing cadherin-1 expression.

Clear cell renal cell carcinoma (ccRCC) is one of the most common types of kidney cancer and is accompanied by a poor prognosis due to a high potential for metastasis and recurrence. The mechanism of ccRCC metastasis is not well known. N-lysine methyltransferase KMT5A serves a crucial role in the progression of human cancer; however, the function of KMT5A in the development of ccRCCs has not yet been investigated, which has triggered an interest in investigating the potential association between KMT5A and ccRCC. The present study demonstrates for the first time that KMT5A is a driving factor in ccRCC metastasis. The KMT5A expression level was revealed to be significantly higher in ccRCC tissues compared with adjacent normal tissues. Patients with ccRCC whose tumors expressed high levels of KMT5A were demonstrated to have significantly shorter postoperative survival times. In vitro knockdown of KMT5A expression in 786-O cells inhibited cell migration and invasion. KMT5A reduced cadherin-1 (CDH1) protein levels by directly inhibiting its transcription. The CDH1 mRNA levels were inversely correlated with KMT5A expression in ccRCC samples. Patients with high tumor KMT5A or low CDH1 levels had the poorest prognosis with the shortest overall survival (OS) time, and this combination was demonstrated to be an independent prognostic indicator for patient OS time in ccRCC, more accurate than monitoring KMT5A or CDH1 alone. Together, these results indicate that KMT5A serves a vital role in ccRCC development and progression, and it may be a novel target for ccRCC treatment and prevention.

[Epidemiological Survey of Thalassemia in Women of childbearing age in Quanzhou Area of Fujian Province in China].

OBJECTIVE: To investigate the gene prevalence and spectrum of thalassemia in the women of childbearing age in quanzhou area. METHODS: Venous blood of the women were collected for study, all subjects were registered in each county of quanzhou area by using cluster sampling. Both the mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were used for screening thalassemia．Genotyping of the screened positive samples was performed by gap single polymerase chain reaction (gap-PCR) and reverse dot blot (RDB) hybridization．Unknown positive samples were analyzed with DNA sequencing. RESULTS: Out of all 7 082 samples, Three hundred and eighty four were identified as thalassemia gene carriers with a carrying rate of 5.42 %. The α and ß thalassemia were 3.21% and 2.15% respectively. --SEA /αα was the most common genotype with 68.72 % in mutation types of α thalassemia, In addition gene, 2 cases of --THAI/αα and 1 case of αα/αααanti3.7 were also detected. IVS-Ⅱ-654/N and CD41-42/N were the most common gentypes with 75.00 % in mutation types of ß thalassemia gene, 5 cases were found to be α ß compogite thalassemia. CONCLUSION: The carrying rate of thalassemia gene in quanzhou area is higher, and with the most common gentypes including --SEA /αα、IVSⅡ-654(C→T)/N and CD41-42(-TTCT)/N. The study results are beneficial for the screening of thalassemia in the genetic consultation and the prenatal gene diagnosis.

Cryo-EM structure reveals cylindrical nucleocapsids from two polydnaviruses.

Bracovirus is one of the two polydnavirus genera. Here, we used a cryo-EM analysis to reveal the near-native morphology of two nucleocapsid-containing model bracoviruses: Microplitis bicoloratus bracovirus (MbBV) and Microplitis mediator bracovirus (MmBV). MbBV and MmBV nucleocapsids have discernable cap structures in two distal regions with relatively high electron density. Adjacent to the end-cap structures are two electron-lucent rings. Some nucleocapsids were uniformly electron-dense and had a distinctive "helix-tail-like structure". Cryo-EM revealed inconsistent nucleocapsid diameters of 34-69.9 nm in MbBV and 46-69.9 nm in MmBV, and the largest observed cylindrical area length was expanded to 126 nm.

Unexpected link between insect innexins and apoptosis of HeLa cells.

Little is known about how mammalian cells respond to the expression of innexins (Inxs), which are known to mediate cell-to-cell communication that causes apoptosis in the cells of the insect Spodoptera litura. The mammalian expression system, p3xFLAG tag protein, containing the CMV promoter, allowed us to construct two C-terminally elongated innexins (Cte-Inxs), SpliInx2 (Inx2-FLAG), and SpliInx3 (Inx3-FLAG), which were predicted to have the same secondary topological structures as the native SpliInx2 and SpliInx3. Here, we found that only the mRNAs of the two Cte-Inxs were expressed under the control of the CMV promoter in HeLa cells. Unexpectedly, mRNA expression of the two Cte-Inxs enhanced apoptosis of HeLa cells. The two Cte-Inx mRNAs were associated with a significant decrease in Akt phosphorylation in HeLa cells undergoing apoptosis. Furthermore, Inx3-FLAG mRNA expression in nonapoptotic HCT116 cells was also associated with a significant decrease in the levels of phosphorylated Akt. Intriguingly, expression of the mRNAs of the two Cte-Inxs did not activate caspase 3, but it markedly reduced Bid levels in HeLa cells undergoing apoptosis. These results suggest that mRNA expression of the two Cte-Inxs may activate a Bid-dependent apoptotic pathway in HeLa cells. Our study demonstrates that invertebrate gap junction mRNAs can function in vertebrate cancer cells as tumor suppressors.

A polydnaviral genome of Microplitis bicoloratus bracovirus and molecular interactions between the host and virus involved in NF-κB signaling.

Polydnaviruses (PDVs) play a critical role in altering host gene expression to induce immunosuppression. However, it remains largely unclear how PDV genes affect host genes. Here, the complete genome sequence of Microplitis bicoloratus bracovirus (MbBV), which is known to be an apoptosis inducer, was determined. The MbBV genome consisted of 17 putative double-stranded DNA circles and 179 fragments with a total size of 336,336 bp and contained 116 open reading frames (ORFs). Based on conserved domains, nine gene families were identified, of which the IκB-like viral ankyrin (vank) family included 28 members and was one of the largest families. Among the 116 ORFs, 13 MbBV genes were expressed in hemocytes undergoing MbBV-induced apoptosis and further analyzed. Three vank genes (vank86, vank92, vank101) were expressed in hemocytes collected from Spodoptera litura larvae parasitized by M. bicoloratus, in which host NF-κB/IκBs, including relish, dorsal, and cactus, were also persistently expressed. When Spli221 cells were infected with MbBV viral particles, mRNA levels of host and viral NF-κB/IκB genes were persistent and also varied in Spli221 cells undergoing virus-induced pre-apoptosis cell from 1 to 5 hours postinfection. Both were then expressed in a time-dependent expression in virus-induced apoptotic cells. These data show that viral IκB-like transcription does not inhibit host NF-κB/IκB expression, suggesting that transcription of these genes might be regulated by different mechanisms.

N-TERMINALLY ELONGATED SpliInx2 AND SpliInx3 REDUCE BACULOVIRUS-TRIGGERED APOPTOSIS VIA HEMICHANNEL CLOSURE.

The hemichannel and gap junction channel are major portals for the release of factors responsible for the effects of apoptotic cells on the spread of apoptosis to neighboring cells and apoptotic corpse clearance, typically by phagocytes. The N-terminal cytoplasmic domain in the connexins, gap junction proteins in vertebrate, has been implicated in regulating channel closure. However, little is known about how the hemichannel close responds to apoptotic signaling transduction leading to the reduction of neighboring cellular apoptosis in an invertebrate. An insect Bac-to-Bac expression system, pFastBac(TM) HT A, allows us to construct an N-terminally elongated SpliInx2 (Nte-Inx2) and SpliInx3 (Nte-Inx3). Here, we demonstrated that recombinant baculovirus Bac-Nte-Inx2 (reBac-Net-Inx2) and Bac-Nte-Inx3 (reBac-Nte-Inx3) closed the endogenous hemichannel on the Sf9 cell surface. Importantly, primary baculovirus infections significantly caused early apoptosis, and this apoptosis was reduced by hemichannel-closed Sf9 cells at 24-h post-infection (PI). Although N-terminal-elongated residue led to the increase in the phosphorylated sites in both Nte-Inx2 and Nte-Inx3 and an additional transmembrane domain in Nte-Inx3, both the proteins localized on the cell surface, suggesting Nte-Inxs proteins could mediate hemichannel closure. Further supporting evidence showed that hemichannel closure was dependent on N-Inxs expressed by baculovirus polyhedrin promoter, which began to express at 18-24 h PI. These results identify an unconventional function of N-terminal-elongated innexins that could act as a plug to manipulate hemichannel closure and provide a mechanism connecting the effect of hemichannel closure directly to apoptotic signaling transduction from intracellular to extracellular compartment.

[Study on Multi-Bands Recognition for Varieties of Mutton by Using Hyperspectral Technologies].

This paper focused on the research on identifying and classifying for mutton varieties of Tan-han hybrid sheep,Yanchi Tan-sheep and small-tailed sheep in Ningxia by using visible/ near-infrared (400~1 000 nm). Near infrared (900~1 700 nm) hyperspectral technologies, baseline and SG convolution smoothing spectra pretreatment methods were applied respectively according to the characteristics of different spectrum bands; the characteristic wavelengths were extracted by using successive projection algorithm (SPA);then combined with linear discriminant analysis (LDA) and radial basis kernel function of support vector machine (RBFSVM) model were applied to identify the different mutton varieties under characteristic wavelengths and full-wave bands. Results showed that there were good effects for mutton varieties identification in different hyperspectral bands, among which Baseline-Fullwave-RBFSVM and the same models under 12 characteristic wavelengths obtained accuracy of 100% and 98.75% in 400~1 000 nm respectively, and Baseline-Fullwave-RBFSVM and the same models under 7 characteristic wavelengths obtained accuracy of 96.25% and 87.80% in 900~1 700 nm respectively.The identification accuracy of RBFSVM nonlinear classification was higher than the LDA linear discriminant result, meanwhile the identification accuracy in 400~1 000 nm bands was better than in 1 000~1 700 nm bands, which explained that the differences of color and texture were more significant than the component contents among the 3 varieties mutton. Combined hyperspectral technologies with RBFSVM models can obtain a better recognition effect of mutton varieties.

Role of PI3K/Akt signaling in the protective effect of magnesium sulfate against ischemia-perfusion injury of small intestine in rats.

BACKGROUND: The protective effects of magnesium sulfate against ischemia-reperfusion injury of the small intestine in Sprague-Dawley (SD) rats have been confirmed in our previous research. However, its exact mechanism is unclear. This study was to evaluate the role of PI3K/Akt signal pathway in the protective effect of magnesium sulfate against ischemia-reperfusion injury of the small intestine in SD rats. METHODS: Rat model of intestinal ischemia-reperfusion injury was used. The SD rats were divided into four groups randomly: sham operation group, ischemia-reperfusion group, magnesium sulfate group and magnesium sulfate plus LY294002 (an inhibitor of PI3K) group. The pathological changes of intestinal mucosa were examined; the activity of diamine oxidase (DAO) in plasma, the plasma contents of malondialdehyde (MDA), and apoptosis rate of the intestinal mucosal cells were determined and compared. The expression of p-Akt was detected by Western blotting. RESULTS: There were more evident pathological changes of the intestinal mucosa (higher Chiu's score, P < 0.05), enhanced DAO activity (P < 0.05), elevated contents of MDA (P < 0.05), higher apoptosis rate (P < 0.05), and lower level of p-Akt (P < 0.05) in the ischemia-reperfusion group compared with the sham operation group. There were less evident pathological changes of the intestinal mucosa (lower Chiu's score, P < 0.05), lower DAO activity (P < 0.05), lower contents of MDA (P < 0.05), and lower apoptosis rate (P < 0.05), but higher level of p-Akt (P < 0.05) in the magnesium sulfate group compared with the ischemia-reperfusion group. There were more evident pathological changes of the intestinal mucosa (higher Chiu's score, P < 0.05), higher contents of MDA (P < 0.05), higher DAO activity (P < 0.05) and higher apoptosis rate (P < 0.05), and lower level of p-Akt (P < 0.05) in the magnesium sulfate plus LY294002 group compared with the magnesium sulfate group. CONCLUSIONS: Activation of PI3K/Akt signal pathway results in the reduction of cell apoptosis, which likely accounts for the protective effect of magnesium sulfate against intestinal ischemia-reperfusion injury.

Improving gas sensing properties of graphene by introducing dopants and defects: a first-principles study.

The interactions between four different graphenes (including pristine, B- or N-doped and defective graphenes) and small gas molecules (CO, NO, NO(2) and NH(3)) were investigated by using density functional computations to exploit their potential applications as gas sensors. The structural and electronic properties of the graphene-molecule adsorption adducts are strongly dependent on the graphene structure and the molecular adsorption configuration. All four gas molecules show much stronger adsorption on the doped or defective graphenes than that on the pristine graphene. The defective graphene shows the highest adsorption energy with CO, NO and NO(2) molecules, while the B-doped graphene gives the tightest binding with NH(3). Meanwhile, the strong interactions between the adsorbed molecules and the modified graphenes induce dramatic changes to graphene's electronic properties. The transport behavior of a gas sensor using B-doped graphene shows a sensitivity two orders of magnitude higher than that of pristine graphene. This work reveals that the sensitivity of graphene-based chemical gas sensors could be drastically improved by introducing the appropriate dopant or defect.