Reproductive biology of an endangered lithophytic shrub and implications for its conservation.

BACKGROUND: Plants in cliff habitats may evolve specific reproductive strategies to cope with harsh environments, and unraveling these reproductive characteristics can improve our understanding of survival strategies and lithophyte evolution. This understanding is especially important for efforts to protect rare and endemic plants. Here, we investigated the reproductive biology of Lonicera oblata, an endangered lithophytic shrub that is scattered in highly fragmented and isolated cliff habitats of the Taihang and Yan mountains in North China. RESULTS: Flowers of L. oblata are herkogamous and protandrous, characteristics that can prevent autogamy at the single-flower level, and insects are necessary for pollination. The outcrossing index, pollen/ovule ratio, and the results of hand pollination were measured and all revealed a mixed mating system for L. oblata, that combines cross-fertilization and partial self-fertilization. The floral traits of L. oblata of zygomorphic and brightly yellowish corolla, heavy fragrance, and rich nectar, suggest an entomophilous pollination system. Sweat bees were observed as the most effective pollinators but their visiting frequencies were not high. Pollen limitation may limit the reproductive success of L. oblata. CONCLUSIONS: We determined the reproductive characteristics of L. oblata, a critically endangered species endemic to cliffs in North China, providing insight into its endangerment and suggesting conservation strategies. L. oblata has highly pollinator-dependent self-fertilization as part of a mixed mating system. Floral features such as low-flowering synchrony, asynchronous anthers dehiscence, and high duration of stigma receptivity, improve pollination efficiency in the case of low pollinator service. Our work provides reference information to understand the survival strategies and conservation of L. oblata and other lithophytes.

Electroacupuncture at different intensities inhibits nociceptive discharges of wide dynamic range neurons in spinal dorsal horn of rats. / ä¸åŒå¼ºåº¦ç”µé’ˆå¯¹å¤§é¼ è„Šé«“èƒŒè§’å¹¿åŠ¨åŠ›ç¥žç»å ƒä¼¤å®³æ€§æ”¾ç”µçš„æŠ‘åˆ¶ä½œç”¨.

OBJECTIVES: To observe the effect of electroacupuncture (EA) at different intensities on nociceptive discharges of wide dynamic range (WDR) neurons in the spinal dorsal horns (DHs) of rats, so as to explore its regulatory characteristics on nociceptive signals at the spinal level. METHODS: A total of 25 male SD rats were used in the present study. A microelectrode array was used to record the discharge activity of WDR neurons in the lumbar spinal DHs of normal rats. After finding the WDR neuron, electrical stimulation (pulse width of 2 ms) was administered to the plantar receptive field (RF) for determining its response component of discharges according to the latency of action potential generation (Aß ï¼»0 to 20 msï¼½, Aδ ï¼»20 to 90 msï¼½, C ï¼»90 to 500 msï¼½ and post-discharge ï¼»500 to 800 msï¼½). High-intensity electrical stimulation was continuously applied to the RF at the paw's plantar surface to induce DHs neuronal windup response. Subsequently, EA stimulation at different intensities (1 mA and 2 mA) was applied to the left "Zusanli"(ST36) at a frequency of 2 Hz/15 Hz for 10 min. The induction of WDR neuronal windup was then repeated under the same conditions. The quantity of nociceptive discharge components and the windup response of WDR neurons before and after EA stimulations at different intensities were compared. RESULTS: Compared to pre-EA, both EA1 mA and EA2 mA significantly reduced the number of Aδ and C component discharges of WDR neurons during stimulation, as well as post-discharge (P<0.01, P<0.001). The inhibitory rate of C component by EA2 mA was significantly higher than that by EA1 mA (P<0.05). Meanwhile, both EA1 mA and EA2 mA attenuated the windup response of WDR neurons (P<0.05, P<0.01), and the effect of EA2 mA was stronger than that of EA1 mA (P<0.05). Further analysis showed that when EA1 mA and EA2 mA respectively applied to both non-receptive field (non-RF) and RF, a significant reduction in the number of Aδ component, C component and post-discharge was observed (P<0.05, P<0.01). EA2 mA at the non-RF and RF demonstrated a significant inhibitory effect on the windup response of WDR neurons (P<0.01, P<0.05), but EA1 mA only at the non-RF showed a significant inhibitory effect on the windup response (P<0.01). CONCLUSIONS: EA can suppress nociceptive discharges of spinal DHs WDR neurons in rats. The inhibitory impact of EA is strongly correlated with the location and intensity of EA stimulation, and EA2 mA has a stronger inhibitory effect than EA1 mA.

The first complete chloroplast genome in Engelhardia sensu stricto, Engelhardia hainanensis Chen: genome characterization and its phylogenetic relationships within the family Juglandaceae.

Trees of Engelhardia are important components of subtropical and tropical forests in South-eastern Asia with great ecological and economic values. However, phylogenetic relationships within Engelhardioideae (Juglandaceae) remains obscure. In this study, we report the first complete chloroplast genome sequences of Engelhardia sensu stricto, Engelhardia hainanensis Chen, a rare species endemic in southern China. Its complete chloroplast genome is 161,574 bp in length, with a typical quadripartite structure that includes a large single-copy region of 91,158 bp, a small single-copy region of 18,790 bp, and its GC content is 35.8%. A total of 128 genes were identified, including 83 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Furthermore, a phylogenetic tree of Juglandaceae was constructed based the complete chloroplast genome sequence, which strongly support the three-subfamily classification system in Juglandaceae, and E. hainanensis was resolved sister to two Alfaropsis species. This study provides valuable genomic information for the species identification and phylogenetic study of Juglandaceae.

Water-soluble single molecular probe for simultaneous detection of viscosity and hydrazine.

Hydrazine (N2H4) can cause serious damage to human health, while intracellular viscosity is highly associated with many diseases and cellular dysfunctions. Herein, we report the synthesis of a dual-responsive organic molecule-based fluorescent probe with excellent water solubility being capable of detection of N2H4 and viscosity through dual-fluorescence channels in "turn on" manner for both. Besides sensitive detection of N2H4 in aqueous solution with detection limit of 0.135 µM, this probe could be used for vapor N2H4 detection in colorimetric and fluorescent manners. In addition, the probe demonstrated viscosity-dependent fluorescence enhancement behavior, and as high as 150-fold enhancement could be obtained at 95% glycerol aqueous solution. Cell imaging experiment revealed that the probe could be used for the discriminating of living and dead cells.

Europium-modified carbon nitride nanosheets for smartphone-based fluorescence sensitive recognition of anthrax biomarker dipicolinic acid.

Development of selective and sensitive methods for the detection of 2, 6-dipicolinic acid (DPA), a biomarker produced by bacterial spores, is of great significance for maintaining public health and food safety. Herein, a ratiometric fluorescence strategy using graphene carbon nitride (g-C3N4) coupled with Eu3+ is designed for the assay of DPA. As the concentration of DPA increases, the emission intensity of g-C3N4 kept constant which acted as a stable internal reference, while the fluorescence of Eu3+ was enhanced obviously due to the antenna effect. The linear calibration ranged from 0.1 to 15 µM with a detection limit of 13 nM was obtained. More Importantly, a paper-based sensor with a smartphone was successfully combined to perform colorimetric and visual detection of DPA in situ. This method has good performance for the detection of DPA, which is expected to broaden the application prospects of preliminary biomarker monitoring.

Dual-responsive ratiometric fluorescent sensor for tetracyclines detection based on europium-decorated copper nanoclusters.

Development of accurate and efficient TCs residue analysis methods is of great significance for the protection of environment, food safety and public health. Herein, a dual-responsive ratiometric fluorescence sensor being capable of simple and sensitive detection of tetracycline (TC) was presented, which was constructed by immobilizing europium ions (Eu3+) onto the mercaptopropionic acid stabilized copper nanoclusters (MPA-Cu NCs). In the presence of TC, the red fluorescence of Eu3+ was enhanced through antenna effect (AE), while the green fluorescence of MPA-Cu NCs was quenched through internal filter effect (IFE), leading to an obvious fluorescence color evolution from green to red for the probe solution. In addition to successful design of a smartphone-assisted colorimetric analysis platform for portable detection, a logic gate device capable of intelligently monitoring TC concentration is also designed.

Genomic Data Reveals Profound Genetic Structure and Multiple Glacial Refugia in Lonicera oblata (Caprifoliaceae), a Threatened Montane Shrub Endemic to North China.

Characterizing genetic diversity and structure and identifying conservation units are both crucial for the conservation and management of threatened species. The development of high-throughput sequencing technology provides exciting opportunities for conservation genetics. Here, we employed the powerful SuperGBS method to identify 33, 758 high-quality single-nucleotide polymorphisms (SNP) from 134 individuals of a critically endangered montane shrub endemic to North China, Lonicera oblata. A low level of genetic diversity and a high degree of genetic differentiation among populations were observed based on the SNP data. Both principal component and phylogenetic analyses detected seven clusters, which correspond exactly to the seven geographic populations. Under the optimal K = 7, Admixture suggested the combination of the two small and geographically neighboring populations in the Taihang Mountains, Dongling Mountains, and Lijiazhuang, while the division of the big population of Jiankou Great Wall in the Yan Mountains into two clusters. High population genetic diversity and a large number of private alleles were detected in the four large populations, while low diversity and non-private alleles were observed for the remaining three small populations, implying the importance of these large populations as conservation units in priority. Demographic history inference suggested two drastic contractions of population size events that occurred after the Middle Pleistocene Transition and the Last Glacial Maximum, respectively. Combining our previous ecological niche modeling results with the present genomic data, there was a possible presence of glacial refugia in the Taihang and Yan Mountains, North China. This study provides valuable data for the conservation and management of L. oblata and broadens the understanding of the high biodiversity in the Taihang and Yan Mountains.

Characterization of the complete chloroplast genome of a subalpine deciduous shrub Lonicera angustifolia var. myrtillus (Caprifoliaceae).

The genus Lonicera (Caprifoliaceae) is of great economical significance. It has been taxonomically studied frequently in history, while phylogenetic relationships intra the genus are still obscure. Here, we reported the first species complete chloroplast genome sequence in the section Isoxylosteum, Lonicera angustifolia var. myrtillus. It is 156,222 bp in length, comprising a large single-copy (LSC) region of 89,838 bp, a small single-copy (SSC) region of 19,211 bp, and a pair of inverted repeats (IRs) of 23,509 bp. In L. angustifolia var. myrtillus chloroplast genome, a total of 114 functional genes were identified, with an overall GC content of 38.4%. The phylogenetic relationships of Lonicera based on maximum-likelihood (ML) showed that L. angustifolia var. myrtillus is most closely related to L. nervosa in section Isika. Our study contributes to the molecular phylogenetic studies of Lonicera and Caprifoliaceae.

Nanostructuring Bridges Semiconductor-Cocatalyst Interfacial Electron Transfer: Realizing Light-Intensity-Independent Energy Utilization and Efficient Sunlight-Driven Photocatalysis.

Despite thermodynamic feasibility, the high activation energy originating from potential barriers and trap states kinetically prevents the interfacial transfer of electrons from semiconductor nanostructures to reduction cocatalysts, resulting in a lowered utilization of photogenerated charge carriers in photocatalysis. Nanostructuring-induced narrowing of potential barriers offers a rational solution to kinetically facilitate interfacial electron transfer by tunneling. Here, inspired by theoretical simulation, we manage to promote the separation of photogenerated charge carriers by coating the semiconductor nanostructures with a homogeneous interlayer. The low activation energy for interfacial electron transfer endows photocatalysis with nearly constant quantum yields and a quasi-first-order reaction to the incident photons and grants evident superiority over the photocatalyst without interlayers, especially under sunlight. In our demonstrated sunlight-driven hydrogen evolution integrated with benzylamine oxidation, the production rates for both reduction and oxidation half-reactions reach as high as ∼0.77 mmol dm-2 h-1, which are ∼10 times higher than that without an interlayer.

Light-Intensity-Dependent Semiconductor-Cocatalyst Interfacial Electron Transfer: A Dilemma of Sunlight-Driven Photocatalysis.

In photocatalytic reactions, the interfacial transfer of electrons from semiconductor nanostructures to cocatalysts is the key step that determines the utilization of photogenerated charges and is sensitively influenced by the behaviors of this electronic process. Under weak illumination, photocatalytic reaction rates deviate from linearity to incident light intensity (r = kss·Pincα, with α → 0.5), because charge recombination predominates interfacial transfer. When the irradiation intensity is high, theoretically, thermionic emission would be the major electronic process (r = kte·Pincα, with α → 2). The ratio of photocatalytic reaction rate to incident light intensity that mainly reflects the energy utilization would encounter a minimum along the variation of irradiation intensity. This crucial relationship, however, has hardly been consciously considered. In this work, inspired by theoretical simulation, we demonstrate that sunlight-driven photocatalysis is generally on the bottom of the energy utilization curves for certain common semiconductors (CdS, TiO2, or C3N4).

The complete chloroplast genome of Symphoricarpos orbiculatus (Caprifoliaceae), an important ornamental plant.

Symphoricarpos orbiculatus is an important landscape and ornamental plant. In this study, we report the complete chloroplast genome sequences of S. orbiculatus. The complete chloroplast genome of S. orbiculatus was 156,044 bp in length. The genome has a typical quadripartite structure, including a large single-copy (LSC) region of 88,756 bp, a small single-copy (SSC) region of 19,130 bp, and two inverted repeat (IR) regions of 24,079 bp each. Overall, the GC content was 38.4%. In the genome, it was identified to comprise130 genes, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. This study provides valuable information for molecular phylogenetic study of Caprifoliaceae and is significant for variety development of Symphoricarpos.

The complete chloroplast genome of Lonicera oblata, a critically endangered species endemic to North China.

Lonicera oblata, a critically endangered species endemic to North China with about 30 wild individuals, has long been ignored for conservation since its publication because of little attention on its living situation. In this study, we characterized the complete chloroplast (cp) genome of L. oblata. The cp genome was 155,481 bp in length, included a large single-copy (LSC) region of 89,139 bp, a small single-copy (SSC) region of 18,676 bp, and two inverted repeat (IR) regions of 23,833 bp each. The genome contains 130 genes, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic position of L. oblata was also investigated based on cp genome phylogeny of Lonicera representatives. This study is valuable for molecular phylogenetic study and conservation of Lonicera and related taxa.

Targeting CDT1 inhibit tumor growth and its mechanism in lung adenocarcinoma / 安徽医科大学学报

Objective To explore the clinical significance and mechanisms of chromatin licensing and DNA repli-cation factor 1(CDT1)in lung adenocarcinoma).Methods The gene expression samples of lung adenocarcinoma tissue and normal lung tissue were downloaded from the TCGA database,and perform differential analysis,GO a-nalysis,independent prognosis analysis,and correlation analysis with immunotherapy using R language.CDT1 ex-pression in lung adenocarcinoma and normal tissues was detected by PCR in clinical samples.The changes of cell proliferation and cycle in si-CDT1 knockdown group and si-NC control group were detected by flow cytometry.The invasive ability of each group was detected by Transwell.The expressions of CDT1,TPX2 and p53 in each group were detected by Western blot.Results The TCGA data analysis revealed CDT1 as a differentially expressed gene.GO analysis indicated that CDT1 was closely associated with the cell cycle.The high expression of CDT1 in lung adenocarcinoma tissues was validated in clinical samples.CDT1 could serve as an independent factor for predicting the prognosis of lung adenocarcinoma and had predictive value for immunotherapy in lung adenocarcinoma.Knock-down of CDT1 resulted in a significant decrease in cell proliferation ability compared to the control group,and cells were noticeably arrested in the G1 phase.Transwell assay results demonstrated a significant reduction in invasive capacity in the CDT1 knockdown group.Knockdown of CDT1 led to a significant decrease in TPX2 expression and a significant increase in p53 expression,while overexpression of CDT1 yielded the opposite effect.Conclusion Re-sults demonstrate the elevated expression of CDT1 in lung adenocarcinoma,its association with prognostic signifi-cance,and its impact on lung adenocarcinoma's occurrence and development by influencing TPX2 and p53.

2,3,5,4'-Tetrahydroxystilbene-2-O-beta-D-glucoside Reverses Stress-Induced Depression via Inflammatory and Oxidative Stress Pathways.

Major depressive disorder (MDD) is a chronic mental disease that adversely affects human mood and cognition. Many first-line antidepressant drugs have high rates of partial responsiveness or nonresponsiveness with side effects, and finding more effective drugs for the treatment of depression is therefore urgently needed. THSG, a main active compound of the traditional Chinese herb Polygonum multiflorum, reportedly acts as a neuroprotective agent. This study aimed to illustrate whether THSG prevents depressive-like behaviors induced by chronic restraint stress (CRS) in an MDD mouse model. Our results demonstrated that the peripheral administration of different THSG doses (10 mg/kg, 20 mg/kg, and 40 mg/kg) reversed the depressive-like behaviors in CRS mice as measured by the tail suspension test, forced swimming test, and open-field test. Further analyses suggested that THSG treatment reduced oxidative stress in both the central and peripheral nervous systems of CRS mice. In addition, heightened inflammatory responses, demonstrated by the increased expression of proinflammatory factors (TNF-α, IL-1ß, and IL-6), in hippocampal and prefrontal cortex tissues of CRS mice were inhibited by THSG administration. THSG also restored the diminished Akt signaling pathway in the brains of CRS mice. Moreover, our data suggest increased astrocyte proliferation and neurogenesis in the hippocampus of CRS mice after THSG treatment. Taken together, our results demonstrated an antidepressant effect of THSG in a mouse model of MDD for the first time, and oxidative stress and inflammatory pathways were determined to play roles in this effect.

Effect of Dichloromethane Extraction Phase of Patrinia Scabiosaefolia Fisch. Stem on Proliferation and Differentiation of K562 Cells / 中国实验血液学杂志

OBJECTIVE@#To explore the effect of dichloromethane extraction phase of ethanol extract from stem of Patrinia scabiosaefolia Fisch.(DPSS) on proliferation and differentiation of K562 cells and its related mechanism.@*METHODS@#MTT assay was used to detect the effects of DPSS at 0, 25, 50, 100 and 200 μg/ml on the proliferation of K562 cells at 24, 48 and 72 hours. Flow cytometry was used to analyze the changes of cell cycle and apoptosis at 24 and 48 hours. Wright-Giemsa staining was used to observe the morphological changes of K562 cells. The cell surface antigens CD33 and CD11b were detected by flow cytometry.@*RESULTS@#The proliferation of K562 cells treated with different concentrations of DPSS was inhibited in a time-dose dependent manner (r=-0.96). Cell cycle analysis showed that with the increase of DPSS concentration, cells in G2/M phase increased (r=0.88), and cells were blocked in G2/M phase. Flow cytometry results showed that with the apoptosis rate of K562 cells was the highest when treated with 200 μg/ml DPSS for 48 h. Morphological observation showed that the K562 cell body increased, the amount of cytoplasm increased, the ratio of nucleus to cytoplasm decreased, and the nuclear chromatin was rough after DPSS treatment. Cell differentiation antigen, CD33 and CD11b, were positively expressed after treated with DPSS.@*CONCLUSION@#DPSS can induce apoptosis through cell cycle arrest, inhibit the proliferation of K562 cells, and induce K562 cells to differentiate into monocytes, which has a potential anti-leukemia effect.

Mechanism of Proliferation and Apoptosis of Acute Promyelocytic Leukemia Cell Line NB4 Induced by TPA / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of phorbol-12-myristate-13-ace-tate (TPA) on the proliferation and apoptosis of acute promyelocytic leukemia cell line NB4 and its molecular mechanism.@*METHODS@#The effect of different concentrations of TPA on the proliferation of NB4 cells at different time points was detected by CCK-8 assay. The morphological changes of NB4 cells were observed by Wright-Giemsa staining. The cell cycle and apoptosis of NB4 cells after TPA treatment were detected by flow cytometry. The mRNA expressions of NB4 cells after TPA treatment were analyzed by high-throughput microarray analysis and real-time quantitative PCR. Western blot was used to detect the protein expression of CDKN1A, CDKN1B, CCND1, MYC, Bax, Bcl-2, c-Caspase 3, c-Caspase 9, PIK3R6, AKT and p-AKT.@*RESULTS@#Compared with the control group, TPA could inhibit the proliferation of NB4 cells, induce the cells to become mature granulocyte-monocyte differentiation, and also induce cell G1 phase arrest and apoptosis. Differentially expressed mRNAs were significantly enriched in PI3K/AKT pathway. TPA treatment could increase the mRNA levels of CCND1, CCNA1, and CDKN1A, while decrease the mRNA level of MYC. It could also up-regulate the protein levels of CDKN1A, CDKN1B, CCND1, Bax, c-Caspase 3, c-Caspase 9, and PIK3R6, while down-regulate MYC, Bcl-2, and p-AKT in NB4 cells.@*CONCLUSION@#TPA induces NB4 cell cycle arrest in G1 phase and promotes its apoptosis by regulating PIK3/AKT signaling pathway.

FAS-1377 G/A (rs2234767) polymorphism and cancer susceptibility: a meta-analysis of 17,858 cases and 24,311 controls.

BACKGROUND AND OBJECTIVES: Disruption of apoptosis has been implicated in carcinogenesis. Specifically, various single-nucleotide polymorphisms (SNPs) in apoptotic genes, such as FAS-1377 G/A SNP, have been associated with cancer risk. FAS-1377 G/A SNP has been shown to alter FAS gene promoter transcriptional activity. Down-regulation of FAS and cell death resistance is key to many cancers, but an association between FAS-1377 G/A SNP and cancer risk is uncertain. Therefore, we conducted a meta-analysis of the current literature to clarify this relationship. METHODOLOGY/PRINCIPAL FINDINGS: From PubMed and Chinese language (CNKI and WanFang) databases, we located articles published up to March 5, 2013, obtaining 44 case-control studies from 41 different articles containing 17,858 cases and 24,311 controls based on search criteria for cancer susceptibility related to the FAS gene -1377 G/A SNP. Odds ratios (ORs) and 95% confidence intervals (CI) revealed association strengths. Data show that the -1377 G allele was protective against cancer risk. Similar associations were detected in "source of control," ethnicity and cancer type subgroups. Lower cancer risk was found in both smokers with a GG+GA genotype and in non-smokers with the GG+GA genotype, when compared to smokers and nonsmokers with the AA genotype. Males carrying the -1377G allele (GG+GA) had lower cancer incidence than those with the AA genotype. Individuals who carried both FAS-1377(GG+GA)/FASL-844(TT+TC) genotypes appeared to have lower risk of cancer than those who carried both FAS-1377 AA/FASL-844 CC genotypes. CONCLUSIONS/SIGNIFICANCE: The FAS-1377 G/A SNP may decrease cancer risk. Studies with larger samples to study gene-environment interactions are warranted to understand the role of FAS gene polymorphisms, especially -1377 G/A SNP, in cancer risk.

Crosstalk of Hedgehog/Gli and PI3k/Akt Pathway Promotes Epithelial-mesenchymal Transition in Gastric Adenocarcinoma / 中国医科大学学报

Objective To investigate the tumor molecular mechanism of Hedgehog/Gli in promoting the epithelial-mesenchymal transition (EMT) in gastric cancer AZ521 cells. Methods After 24 h of treatment with GANT61,the mRNA expression of Gli1,Gli2, N-cadherin,and E-cadherin in the AZ521 cell line were detected by real-time fluorescence quantitative PCR. A Western blotting assay was conducted to determine the expression of the above cytokines,p-AKT and AKT. The effect of GANT61 on invasion was observed by transwell assay. N-Shh stimulation of the Hedgehog pathway was conducted to confirm the changes in these cytokines. Results GANT61 significantly downregulated the mRNA expression of Gli1,Gli2,and N-cadherin,but upregulated E-cadherin mRNA expression. The Western blotting assay revealed that GANT61 downregulated the protein expression of Gli1,Gli2,p-AKT,and N-cadherin,but upregulated E-cadherin expression. Furthermore,GANT61 inhibited the invasion. N-Shh proteins up-regulated Gli1,Gli2,and N-cadherin mRNA,protein expression and p-AKT protein expression,but downregulated E-cadherin mRNA and protein expressions. N-Shh promoted the invasion of tumor cells. Conclusion Downregulation of Gli1 and Gli2 can inhibit the invasion and metastasis in gastric cancer cells,which may be related to the promotion of EMT by Gli through the PI3K/AKT pathway.

Neural mechanism for encoding rhythmic information:a review / 中国药理学与毒理学杂志

Extracting and encoding rhythmic information is very important for brain functions, as it is the foundation of speech recognition,music appreciation and rhythmic movement et al.However,our knowledge of how the neural system processes rhythm information of external inputs remains limited. In the present paper,we review a neural network model of the scale-free topology can serve as an efficient way to encode rhythm information. In the model, neurons are connected by either electrical synapses or chemical synapses with strengths decreasing with the connectivity of neurons, so that hub neurons are difficult to activate. To encode rhythm information, hub neurons trigger synchronous firing across the network, while loops formed by low-degree neurons determine the rhythm of synchronous firing. This model successfully reproduces the long-period synchronous firing observed in experimental data, and indicates that the neural system can encode temporal information via local dynamics in a distributed way.This review aims to elaborate and summarize the mechanism by which neurons encode rhythmic information.

MMP7 -181G allele is a low-penetrant risk factor for cancer development in East Asians.

Matrix metalloproteinase-7 (MMP-7) is a small secreted proteolytic enzyme with broad substrate specificity. Its expression is associated with tumor invasion, metastasis, and survival for a number of cancers. However, data from published studies with individually low statistical power are conflicting. Here, we performed a meta-analysis of 14 publications (16 case-control studies) to better assess the purported relationship. Eligible studies were identified by searching the Pubmed database. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association. Overall, we found that the -181 G allele increased cancer risk in East Asians (G-allele vs. A-allele, OR=1.35, 95% CI: 1.25-1.46, P(heterogeneity)=0.01; GA vs. AA, OR=1.40, 95% CI: 1.16-1.69, P(heterogeneity)=0.04; GG+GA vs. AA, OR=1.52, 95% CI: 1.30-1.78, P(heterogeneity)=0.00). Similarly, in the stratified analysis by cancer type and source of control, significantly increased cancer risk was indicated. Our study showed evidence that MMP7 -181A/G polymorphism may increase cancer risk in the East Asian population. Future studies with larger sample size are warranted to further evaluate this association in greater detail.