Effects of interaction of multiple large-scale atmospheric circulations on precipitation dynamics in China.

Different scenarios of precipitation, that lead to such phenomena as droughts and floods are influenced by concurrent multiple teleconnection factors. However, the multivariate relationship between precipitation indices and teleconnection factors, including large-scale atmospheric circulations and sea surface temperature signals in China, is rarely explored. Understanding this relationship is crucial for drought early warning systems and effective response strategies. In this study, we comprehensively investigated the combined effects of multiple large-scale atmospheric circulation patterns on precipitation changes in China. Specifically, Pearson correlation analysis and Partial Wavelet Coherence (PWC) were used to identify the primary teleconnection factors influencing precipitation dynamics. Furthermore, we used the cross-wavelet method to elucidate the temporal lag and periodic relationships between multiple teleconnection factors and their interactions. Finally, the multiple wavelet coherence analysis method was used to identify the dominant two-factor and three-factor combinations shaping precipitation dynamics. This analysis facilitated the quantification and determination of interaction types and influencing pathways of teleconnection factors on precipitation dynamics, respectively. The results showed that: (1) the Atlantic Multidecadal Oscillation (AMO), EI Niño-Southern Oscillation (ENSO), East Asia Summer Monsoon (EASM), and Indian Ocean Dipole (IOD) were dominant teleconnection factors influencing Standardized Precipitation Index (SPI) dynamics; (2) significant correlation and leading or lagging relationships at different timescales generally existed for various teleconnection factors, where AMO was mainly leading the other factors with positive correlation, while ENSO and Southern Oscillation (SO) were mainly lagging behind other factors with prolonged correlations; and (3) the interactions between teleconnection factors were quantified into three types: enhancing, independent and offsetting effects. Specifically, the enhancing effect of two-factor combinations was stronger than the offsetting effect, where AMO + NAO (North Atlantic Oscillation) and AMO + AO (Atlantic Oscillation) had a larger distribution area in southern China. Conversely, the offsetting effect of three-factor combinations was more significant than that of the two-factor combinations, which was mainly distributed in northeast and northwest regions of China. This study sheds new light on the mechanisms of modulation and pathways of influencing various large-scale factors on seasonal precipitation dynamics.

Segmental analysis of liver cirrhosis with different etiologies: a study based on iodine mixed imaging in port-venous phase.

BACKGROUND: Computed tomography (CT) in port-venous phase can display the intra-hepatic vessels, and may provide the possibility for segment function evaluation for cirrhosis. PURPOSE: To assess the value of iodine mixed imaging of dual-source dual-energy CT in port-venous phase in segmental evaluation of liver cirrhosis with different etiologies. MATERIAL AND METHODS: Patients diagnosed with liver cirrhosis were enrolled. Patients without cirrhosis were included as a control group. Each patient underwent iodine-contrast enhanced multi-phase dual-energy CT scanning. Parameters were analyzed by SPSS, version 22.0, and Medcalc. RESULTS: In total, 256 patients were investigated, including 114 Child-Pugh A, 51 Child-Pugh B, 41 Child-Pugh C and 50 control patients. Total iodine content (ICt)/body surface area (BSA) in the cirrhosis group was significantly lower than the control group (P < 0.05) and the standardized-iodine parameter (SI) of each segment decreased with cirrhosis progression. In Child-Pugh A and B, SI increased more significantly in the caudal and lateral segment in A (alcholism) than in the V (virus-related) and N (non-alcoholic steatohepatitis) groups (P < 0.001). ICt/BSA showed the best diagnosis power of cirrhosis with an area under the curve of 0.765, sensitivity of 76.0% and specificity of 71.8%. CONCLUSION: Blood flow compensated in the left lateral and caudal lobe in the early stage of liver cirrhosis. The compensation in alcoholism in the middle and early stages is significantly higher than that of V and N cirrhosis. Iodine mixed imaging in portal phase may provide the possibility of an incremental value in segmented blood flow perfusion and functional evaluation of liver cirrhosis on a morphological basis.

Effects and mechanisms on the reduction of lead accumulation in rice grains through lime amendment.

The influence of lime amendment on the absorption and accumulation of lead (Pb) in the grains of three rice cultivars ((Dong Lian 5 (DL-5, Indica), TeYou 009 (TY-009, Hybrid Indica), and YiYou 673 (YY-673, Hybrid Indica)) was investigated and the associated mechanisms were explored. Pot experiment was conducted in heavily Pb-polluted paddy soil. The transformation of Pb species in soil and roots under different levels of lime application was studied by Pb L3-edge X-ray absorption spectroscopy (Pb L3-XAS) and BCR sequential extraction. The results showed that lime amendment significantly increased soil pH and decreased DTPA-extractable Pb in soil. When the additional ratio of Liming was lower than 32 g kg-1, the Pb accumulation in rice plants, particularly in the grains was remarkably reduced. Moreover the biomass of rice was not significantly affected. Among the three cultivars, the lowest Pb content in rice grains occurred in YY-673. The cultivation of rice cultivar with low Pb accumulation will reduce the Pb content in the grains. Liming significantly inhibited the translocation of Pb from the roots to the aboveground parts, and from the stems and leaves to grains. Pb L3-XAS and BCR s sequential extraction method analysis revealed that lime amendment increased Pb2+ association with Fe oxides (Pb-Ferr), the precipitation of 2PbCO3·Pb(OH)2, the residual fraction of paddy soil, and also promoted the transformation of Pb(NO3)2 and Pb-pectin to 2PbCO3·Pb(OH)2 and Pb-Ferr in rice roots. The suitable lime addition (> 4 g kg-1, under this pot experiment) could effectively reduce Pb accumulation in rice grains.

Mixed Imaging on Port-Venous Phase of Contrast-Enhanced Dual-Source Dual-Energy Computed Tomography: A Measurement Method Based on Couinaud Segments.

OBJECTIVE: The aim of this study was to evaluate the changes of the iodine value quantified on the Couinaud segments measured in port-venous phase using the iodine-mixed technique of contrast-enhanced dual-source dual-energy computed tomography (CT) scanning in different Child-Pugh stages of hepatitis B-induced liver cirrhosis. METHODS: Patients clinically diagnosed with hepatitis B-induced cirrhosis were prospectively engaged in our study. Each patient underwent multiphase iodine agent contrast-enhanced dual-source dual-energy CT scanning, and then the iodine-mixed imaging of port-venous phase was postprocessed. Iodine concentration was obtained for each segment based on the Couinaud segments. The volume of each segment and the total of the liver were measured and calculated using the postprocessing software of volume. All the cirrhosis patients were grouped into 3 subgroups based on the Child-Pugh stage method. Patients without cirrhosis were engaged for the control group. The iodine concentration, volume, and iodine storage among groups were analyzed by SPSS version 19.0. Single energy was used for the nonenhanced phase scanning, which was used for the radiation dosage comparison with dual-energy CT scanning. RESULTS: Two hundred three patients were ultimately enrolled in our study, including 148 patients with cirrhosis (Child A, 69; Child B, 51; Child C, 28) and 55 patients without cirrhosis as control subjects. The total volume and iodine storage of cirrhosis group were smaller than those of the control group (P < 0.001). Compared with the control group, the iodine concentration in each segment decreased with progression of cirrhosis. The volume, iodine concentration, and iodine storage of the right hepatic lobe and left medial segment decreased with cirrhosis severity (P < 0.001). There was no significant difference in the volume of right hepatic lobe between Child C group and Child B group, whereas the iodine storage of Child C group was lower than that of Child B group (P < 0.05). The volume and iodine storage of left lateral segment increased with the progression of liver cirrhosis in the Child A and Child B groups (P < 0.05), whereas there was no statistical difference between the Child B and Child C groups, and the iodine storage in the Child C group was lower than that of the Child B group (P < 0.05). The radiation dose of dual-energy scanning was lower than that of single-energy scanning (P < 0.001). The iodine concentration 1.512 mg/mL on the left medial segment reached the most optimal evaluation on cirrhosis, with a sensitivity of 100%, specificity of 0.722, and area under the curve of 0.914. CONCLUSIONS: Iodine concentration in portal phase measurement can evaluate and reflect the severity of cirrhosis. Iodine content segmental quantification can analyze the changes of the liver storage with a progression of cirrhosis. Dual-energy scanning reduced the radiation damage in patients and is valuable for a further study and clinical application.

Diffusion tensor imaging of breast lesions: evaluation of apparent diffusion coefficient and fractional anisotropy and tissue cellularity.

OBJECTIVE: To investigate the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) measured by diffusion tensor imaging (DTI), tissue cellularity and their relationship in breast malignant/benign lesions. METHODS: 88 patients with 88 breast lesions who underwent DTI and dynamic contrast-enhanced MR scanning between November 2013 and December 2014 were retrospectively analyzed. The diagnosis was confirmed pathologically. ADC and FA values as well as histopathological cellularity of different pathological types of lesions were analyzed and compared statistically. The Pearson's correlation between cellularity and ADC and FA was calculated. RESULTS: There were 59 cases of breast cancer and 29 cases of benign lesions included in the study. ADC values of breast cancers were statistically lower than that of benign lesions (p < 0.001). FA and cellularity were higher in cancers than in benign lesions with statistical significance (p < 0.05 and p < 0.001, respectively). The mean FA values in the patients with invasive ductal carcinoma (IDC) were higher than that in the patients with ductal carcinoma in situ (DCIS) without statistical difference (p > 0.05). The ADC and the cellularity in the IDC of grade III were statistically lower (p < 0.05) and higher (p < 0.05) than that in the DCIS and IDC of grade I-II, respectively. ADC was negatively correlated to cellularity (r = -0.8319, p < 0.001) and FA was positively correlated to cellularity (r = 0.4231, p < 0.001). CONCLUSION: ADC and FA values were statistically different between benign and malignant breast lesions and were significantly correlated to tissue cellularity. ADC and FA may help to discriminate malignant from benign breast lesions and to predict cellularity. ADC is helpful in the prediction of the grade of breast cancer. ADVANCES IN KNOWLEDGE: ADC and FA values were statistically different between benign and malignant breast lesions and were significantly correlated to tissue cellularity.

Metal-semiconductor-metal transition in zigzag carbon nanoscrolls.

Similar to rolling up paper, carbon nanoscrolls (CNSs) can be rolled from graphene nanoribbons (GNRs) using physical approaches. Owing to their peculiar one-dimensional nanostructures, CNSs have attracted great attention over the past few years. In this study, we have investigated the effects of bending deformation on the electronic properties of zigzag CNSs (ZCNSs) during the rolling process from zigzag GNRs (ZGNRs) by means of first-principles calculations. It is found that a metal-semiconductor-metal transition is observed. By analyzing charge density and density of states, the origin of this electronic property transition is discussed. Furthermore, we find that the metal-semiconductor-metal transition in ZCNSs is independent of ribbon width as well as spin-orbit interaction. Our results of the metal-semiconductor-metal transition in the ZCNSs are robust and may open potential applications in nano-electromechanical devices based on the ZCNSs.

Robust superhydrophobic bridged silsesquioxane aerogels with tunable performances and their applications.

Aerogels are a family of highly porous materials whose applications are commonly restricted by poor mechanical properties. Herein, thiol-ene chemistry is employed to synthesize a series of novel bridged silsesquioxane (BSQ) precursors with various alkoxy groups. On the basis of the different hydrolyzing rates of the methoxy and ethoxy groups, robust superhydrophobic BSQ aerogels with tailorable morphology and mechanical performances have been prepared. The flexible thioether bridge contributes to the robustness of the as-formed aerogels, and the property can be tuned on the basis of the distinct combinations of alkoxy groups with the density of the aerogels almost unchanged. To the best of our knowledge, the lowest density among the ambient pressure dried aerogels is obtained. Further, potential application of the aerogels for oil/water separation and acoustic materials has also been presented.

The Protective Effects of IGF-1 on Different Subpopulations of DRG Neurons with Neurotoxicity Induced by gp120 and Dideoxycytidine In Vitro.

Peripheral neuropathy induced by human immunodeficiency virus (HIV) infection and antiretroviral therapy is not only difficult to distinguish in clinical practice, but also difficult to relieve the pain symptoms by analgesics because of the severity of the disease at the later stage. Hence, to explore the mechanisms of HIV-related neuropathy and find new therapeutic options are particularly important for relieving neuropathic pain symptoms of the patients. In the present study, primary cultured embryonic rat dorsal root ganglion (DRG) neurons were used to determine the neurotoxic effects of HIV-gp120 protein and/or antiretroviral drug dideoxycytidine (ddC) and the therapeutic actions of insulin-like growth factor-1 (IGF-1) on gp120- or ddC-induced neurotoxicity. DRG neurons were exposed to gp120 (500 pmol/L), ddC (50 µmol/L), gp120 (500 pmol/L) plus ddC (50 µmol/L), gp120 (500 pmol/L) plus IGF-1 (20 nmol/L), ddC (50 µmol/L) plus IGF-1 (20 nmol/L), gp120 (500 pmol/L) plus ddC (50 µmol/L) plus IGF-1 (20 nmol/L), respectively, for 72 hours. The results showed that gp120 and/or ddC caused neurotoxicity of primary cultured DRG neurons. Interestingly, the severity of neurotoxicity induced by gp120 and ddC was different in different subpopulation of DRG neurons. gp120 mainly affected large diameter DRG neurons (>25 µm), whereas ddC mainly affected small diameter DRG neurons (≤25 µm). IGF-1 could reverse the neurotoxicity induced by gp120 and/or ddC on small, but not large, DRG neurons. These data provide new insights in elucidating the pathogenesis of HIV infection- or antiretroviral therapy-related peripheral neuropathy and facilitating the development of novel treatment strategies.

Bioinspired materials: from low to high dimensional structure.

The surprising properties of biomaterials are the results of billions of years of evolution. Generally, biomaterials are assembled under mild conditions with very limited supply of constituents available for living organism, and their amazing properties largely result from the sophisticated hierarchical structures. Following the biomimetic principles to prepare manmade materials has drawn great research interests in materials science and engineering. In this review, we summarize the recent progress in fabricating bioinspired materials with the emphasis on mimicking the structure from one to three dimensions. Selected examples are described with a focus on the relationship between the structural characters and the corresponding functions. For one-dimensional materials, spider fibers, polar bear hair, multichannel plant roots and so on have been involved. Natural structure color and color shifting surfaces, and the antifouling, antireflective coatings of biomaterials are chosen as the typical examples of the two-dimensional biomimicking. The outstanding protection performance, and the stimuli responsive and self-healing functions of biomaterials based on the sophisticated hierarchical bulk structures are the emphases of the three-dimensional mimicking. Finally, a summary and outlook are given.

Mussel inspired modification of polypropylene separators by catechol/polyamine for Li-ion batteries.

Inspired by the remarkable adhesion of mussel, dopamine, a mimicking adhesive molecule, has been widely used for surface modification of various materials ranging from organic to inorganic. However, dopamine and its derivatives are expensive which impede their application in large scale. Herein, we replaced dopamine with low-cost catechol and polyamine (only 8% of the cost of dopamine), which could be polymerized in an alkaline solution and deposited on the surfaces of various materials. By using this cheap and simple modification method, polypropylene (PP) separator could be transformed from hydrophobic to hydrophilic, while the pore structure and mechanical property of the separator remained intact. The uptake of electrolyte increased from 80% to 270% after the hydrophilic modification. Electrochemical studies demonstrated that battery with the modified PP separator had a better Coulombic efficiency (80.9% to 85.3%) during the first cycle at a current density of 0.1 C, while the discharging current density increased to 15 C and the discharge capacity increased by 1.4 times compared to the battery using the bare PP separator. Additionally, the modification allowed excellent stability during manifold cycles. This study provides new insights into utilizing low-cost chemicals to mimic the mussel adhesion and has potential practical application in many fields.

Neuroprotective effect of insulin-like growth factor-1: effects on tyrosine kinase receptor (Trk) expression in dorsal root ganglion neurons with glutamate-induced excitotoxicity in vitro.

Insulin-like growth factor-1 (IGF-1) may play an important role in regulating the expression of distinct tyrosine kinase receptor (Trk) in primary sensory dorsal root ganglion (DRG) neurons. Glutamate (Glu) is the main excitatory neurotransmitter and induces neuronal excitotoxicity for primary sensory neurons. It is not known whether IGF-1 influences expression of TrkA, TrkB, and TrkC in DRG neurons with excitotoxicity induced by Glu. In the present study, primary cultured DRG neurons with Glu-induced excitotoxicity were used to determine the effects of IGF-1 on TrkA, TrkB, and TrkC expression. The results showed that IGF-1 increased the expression of TrkA and TrkB and their mRNAs, but not TrkC and its mRNA, in primary cultured DRG neurons with excitotoxicity induced by Glu. Interestingly, neither the extracellular signal-regulated protein kinase (ERK1/2) inhibitor PD98059 nor the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 blocked the effect of IGF-1, but both inhibitors together were effective. IGF-1 may play an important role in regulating different Trk receptor expression in DRG neurons through ERK1/2 and PI3K/Akt signaling pathways. The contribution of distinct Trk receptors might be one of the mechanisms that IGF-1 rescues dying neurons from Glu excitotoxic injury. These data imply that IGF-1 signaling might be a potential target on modifying distinct Trk receptor-mediated biological effects of primary sensory neurons with excitotoxicity.

[Study on the mechanism of interaction between TH-PF-Mo(VI) complex and bovine serum albumin by fluorimetric method].

The mechanism of interaction between bovine serum albumin (BSA) and trihydroxylphenylfluorone (TH-PF)-Mo(VI) complex in neutral solution was studied by fluorimetric method. The mechanism of fluorescence quenching of BSA caused by (TH-PF)-Mo(VI) complex probe was investigated and the binding constants under different temperature were measured. The binding constants of the reaction at 25 degrees C and 40 degrees C were calculated by fluorimetric method to be 4.78 x 10(4) L x mol(-1) and 3.72 x 10(4) L x mol(-1), respectively. According to the theory of Forster non-radiation energy transfer, the binding distance and transfer efficiency at 25 degrees C were calculated to be 2.89 nm and 0.314, respectively. Furthermore, the thermodynamic parameters were measured and the results indicated that electrostatic force played a major role in the interaction between TH-PF-Mo(VI) complex and BSA.