Search

Superlattices-a periodic stacking of two-dimensional layers of two or more materials-provide a versatile scheme for engineering materials with tailored properties1,2. Here we report an intrinsic heterodimensional superlattice consisting of alternating layers of two-dimensional vanadium disulfide (VS2) and a one-dimensional vanadium sulfide (VS) chain array, deposited directly by chemical vapour deposition. This unique superlattice features an unconventional 1T stacking with a monoclinic unit cell of VS2/VS layers identified by scanning transmission electron microscopy. An unexpected Hall effect, persisting up to 380 kelvin, is observed when the magnetic field is in-plane, a condition under which the Hall effect usually vanishes. The observation of this effect is supported by theoretical calculations, and can be attributed to an unconventional anomalous Hall effect owing to an out-of-plane Berry curvature induced by an in-plane magnetic field, which is related to the one-dimensional VS chain. Our work expands the conventional understanding of superlattices and will stimulate the synthesis of more extraordinary superstructures. Ministry of Education (MOE) National Research Foundation (NRF) Submitted/Accepted version The work was supported by: the National Key R&D Program of China (grant number 2020YFA0308800), the NSF of China (grant numbers 12074009, 11774009, 62174013, 12061131102 and 11734003), BIT (number 2021CX11013) and the National Key R&D Program of China (2017YFA0206301); the National Research Foundation, Singapore, under its Competitive Research Programme (NRF-CRP22-2019-0007 and NRF-CRP22-2019-0004), under its NRF-ISF joint research programme (NRF2020-NRF-ISF004-3520); and the Ministry of Education, Singapore, under its AcRF Tier 3 Programme ‘Geometrical Quantum Materials’ (MOE2018-T3-1-002). H.D., and W.G. acknowledge funding from the National Key Basic Research Program of China (2017YFB0701603) and NSFC (number 51971037). We thank X. Dai and H. M. Weng for discussions and their preliminary attempts on ab initio calculations. Y.-C.L. and K.S. acknowledge the JSPS-KAKENHI (JP16H06333 and JP22H05478), (18K14119), the JST-CREST programme (JPMJCR20B1, JMJCR20B5 and JPMJCR1993), the JSPS A3 Foresight Program, and the Kazato Research Encouragement Prize. Y.G. acknowledges funding from the Innovation Program of Shanghai Municipal Education Commission (number 2019-01-07-00- 09-E00020), Shanghai Municipal Science and Technology Commission (18JC1412800). Jianhui Zhou was supported by the High Magnetic Field Laboratory of Anhui Province. Yugui Yao acknowledges the Strategic Priority Research Program of Chinese Academy of Sciences (grant number XDB30000000).

Backgrounds The respiratory microbiota and radiomics correlate with the disease severity and prognosis of chronic obstructive pulmonary disease (COPD). We aim to characterize the respiratory microbiota and radiomics features of COPD patients and explore the relationship between them. Methods Sputa from stable COPD patients were collected for bacterial 16 S rRNA gene sequencing and fungal Internal Transcribed Spacer (ITS) sequencing. Chest computed tomography (CT) and 3D-CT analysis were conducted for radiomics information, including the percentages of low attenuation area below − 950 Hounsfield Units (LAA%), wall thickness (WT), and intraluminal area (Ai). WT and Ai were adjusted by body surface area (BSA) to WT/$$\sqrt{\text{B}\text{S}\text{A}}$$ and Ai/BSA, respectively. Some key pulmonary function indicators were collected, which included forced expiratory volume in one second (FEV1), forced vital capacity (FVC), diffusion lung carbon monoxide (DLco). Differences and correlations of microbiomics with radiomics and clinical indicators between different patient subgroups were assessed. Results Two bacterial clusters dominated by Streptococcus and Rothia were identified. Chao and Shannon indices were higher in the Streptococcus cluster than that in the Rothia cluster. Principal Co-ordinates Analysis (PCoA) indicated significant differences between their community structures. Higher relative abundance of Actinobacteria was detected in the Rothia cluster. Some genera were more common in the Streptococcus cluster, mainly including Leptotrichia, Oribacterium, Peptostreptococcus. Peptostreptococcus was positively correlated with DLco per unit of alveolar volume as a percentage of predicted value (DLco/VA%pred). The patients with past-year exacerbations were more in the Streptococcus cluster. Fungal analysis revealed two clusters dominated by Aspergillus and Candida. Chao and Shannon indices of the Aspergillus cluster were higher than that in the Candida cluster. PCoA showed distinct community compositions between the two clusters. Greater abundance of Cladosporium and Penicillium was found in the Aspergillus cluster. The patients of the Candida cluster had upper FEV1 and FEV1/FVC levels. In radiomics, the patients of the Rothia cluster had higher LAA% and WT/$$\sqrt{\text{B}\text{S}\text{A}}$$ than those of the Streptococcus cluster. Haemophilus, Neisseria and Cutaneotrichosporon positively correlated with Ai/BSA, but Cladosporium negatively correlated with Ai/BSA. Conclusions Among respiratory microbiota in stable COPD patients, Streptococcus dominance was associated with an increased risk of exacerbation, and Rothia dominance was relevant to worse emphysema and airway lesions. Peptostreptococcus, Haemophilus, Neisseria and Cutaneotrichosporon probably affected COPD progression and potentially could be disease prediction biomarkers.

Loss of TGF-β-mediated growth suppression is a major contributor to the development of cancers, best exemplified by loss-of-function mutations in genes encoding components of the TGF-β signaling pathway in colorectal and pancreatic cancers. Alternatively, gain-of-function oncogene mutations can also disrupt antiproliferative TGF-β signaling. However, the molecular mechanisms underlying oncogene-induced modulation of TGF-β signaling have not been extensively investigated. Here, we show that the oncogenic BCR-ABL1 of chronic myelogenous leukemia (CML) and the cellular ABL1 tyrosine kinases phosphorylate and inactivate Smad4 to block antiproliferative TGF-β signaling. Mechanistically, phosphorylation of Smad4 at Tyr195, Tyr301, and Tyr322 in the linker region interferes with its binding to the transcription co-activator p300/CBP, thereby blocking the ability of Smad4 to activate the expression of cyclin-dependent kinase (CDK) inhibitors and induce cell cycle arrest. In contrast, the inhibition of BCR-ABL1 kinase with Imatinib prevented Smad4 tyrosine phosphorylation and re-sensitized CML cells to TGF-β-induced antiproliferative and pro-apoptotic responses. Furthermore, expression of phosphorylation-site-mutated Y195F/Y301F/Y322F mutant of Smad4 in Smad4-null CML cells enhanced antiproliferative responses to TGF-β, whereas the phosphorylation-mimicking Y195E/Y301E/Y322E mutant interfered with TGF-β signaling and enhanced the in vivo growth of CML cells. These findings demonstrate the direct role of BCR-ABL1 tyrosine kinase in suppressing TGF-β signaling in CML and explain how Imatinib-targeted therapy restored beneficial TGF-β anti-growth responses.

With the rise of neural network, deep learning technology is more and more widely used in various fields. Federated learning is one of the training types in deep learning. In federated learning, each user and cloud server (CS) cooperatively train a unified neural network model. However, in this process, the neural network system may face some more challenging problems exemplified by the threat of user privacy disclosure, the error of server’s returned results, and the difficulty of implementing the trusted center in practice. In order to solve the above problems simultaneously, we propose a verifiable federated training scheme that supports privacy protection over deep neural networks. In our scheme, the key exchange technology is used to remove the trusted center, the double masking protocol is used to ensure that the privacy of users is not disclosed, and the tag aggregation method is used to ensure the correctness of the results returned by the server. Formal security analysis and comprehensive performance evaluation indicate that the proposed scheme is secure and efficient.

Cancer stem cells (CSCs) are a small proportion of cancer cells with high tumorigenic activity, self-renewal ability, and multilineage differentiation potential. Standard anti-tumor therapies including conventional chemotherapy, radiation therapy, and molecularly targeted therapies are not effective against CSCs, and often lead to enrichment of CSCs that can result in tumor relapse. Therefore, it is hypothesized that targeting CSCs is key to increasing the efficacy of cancer therapies. In this review, CSC properties including CSC markers, their role in tumor growth, invasiveness, metastasis, and drug resistance, as well as CSC microenvironment are discussed. Further, CSC-targeted strategies including the use of targeted drug delivery systems are examined.

The coal and biomass coupling power generation technology is considered as a promising technology for energy conservation and emission reduction. In this paper, a novel coal and biomass indirect coupling system is proposed based on the technology of biomass gasification and co-combustion of coal and gasification gas. For the sake of comparison, a coal and biomass direct coupling system is also introduced based on the technology of co-combustion of coal and biomass. The process of the direct and the indirect coupling system is simulated. The thermodynamic and economic performances of two systems are analyzed and compared. The simulation indicates that the thermodynamic performance of the indirect coupling system is slightly worse, but the economic performance is better than that of the direct coupling system. When the blending ratio of biomass is 20%, the energy and exergy efficiencies of the indirect coupling system are 42.70% and 41.14%, the internal rate of return (IRR) and discounted payback period (DPP) of the system are 25.68% and 8.56 years. The price fluctuation of fuels and products has a great influence on the economic performance of the indirect coupling system. The environmental impact analysis indicates that the indirect coupling system can inhibit the propagation of NOx and reduce the environmental cost.

Natural products from marine-derived fungi have attracted considerable attention in the recent two decades. Indolediketopiperazines are one of the most important classes of marine natural products, mainly discovered from the fungal genera Penicillium, Aspergillus and Eurotium. These compounds span a wide range of chemical structures and bioactivities. This review summarizes 155 indolediketopiperazines that were discovered from marine-derived fungi from 2000 to early 2019 and primarily focuses on their chemical diversity and biological function.

The coculture of marine red algal-derived endophytic fungi Aspergillus terreus EN-539 and Paecilomyces lilacinus EN-531 induced the production of a new terrein derivative, namely asperterrein (1) and a known dihydroterrein (2), which were not detected in the axenic cultures of both strains. The production of the known secondary metabolites terrein (3), butyrolactone I (4), and dankasterone (6), derived from A. terreus EN-539, were depressed significantly in the coculture. Compounds 1–3 exhibited inhibitory activity against Alternaria brassicae, Escherichia coli, Physalospora piricola, and Staphylococcus aureus with MIC values ranging from 4 to 64 μg ml−1.

Natural killer (NK) cells are critical mediators of host immunity to pathogens. Here, we demonstrate that the endoplasmic reticulum stress sensor inositol-requiring enzyme 1 (IRE1α) and its substrate transcription factor X-box-binding protein 1 (XBP1) drive NK cell responses against viral infection and tumors in vivo. IRE1α-XBP1 were essential for expansion of activated mouse and human NK cells and are situated downstream of the mammalian target of rapamycin signaling pathway. Transcriptome and chromatin immunoprecipitation analysis revealed c-Myc as a new and direct downstream target of XBP1 for regulation of NK cell proliferation. Genetic ablation or pharmaceutical blockade of IRE1α downregulated c-Myc, and NK cells with c-Myc haploinsufficency phenocopied IRE1α-XBP1 deficiency. c-Myc overexpression largely rescued the proliferation defect in IRE1α-/- NK cells. Like c-Myc, IRE1α-XBP1 also promotes oxidative phosphorylation in NK cells. Overall, our study identifies a IRE1α-XBP1-cMyc axis in NK cell immunity, providing insight into host protection against infection and cancer.

Dinuclear metal-mediated hetero base pairs with the d10–d10 closed-shell interactions have significant stability. It is interesting to identify whether coinage metal-mediated Wobble base pairs are also stable. Geometric and electronic structures of the lowest-lying isomers of GUM22+ (G = guanine, U = uracil, M = Cu, Ag, and Au) cluster ions were investigated with density functional theory. In the lowest-lying isomers of these dinuclear metal-mediated base pairs, the 2-oxo-4-hydroxy-trans-N1H isomer of uracil is derived from the canonical tautomer of uracil by the hydrogen atom transfer. M22+ cations remain as an unbroken unit and interact with the G···U ligand through two sets of closely linear N···M···O units, while the reciprocal hydrogen bonds between the Wobble base pair (G–U) are entirely substituted by the M–N or M–O interactions in these complexes. The atoms in molecules and EDA–NOCV calculations really reveal that the σ interactions in GUM22+ cations are the paramount term of ΔEOrb. The obtained instantaneous interaction energies ΔEint and bond dissociation energies of the metal–ligand interactions give the trend of the bond strength as Cu > Au > Ag.

Background Particulated juvenile allograft cartilage (PJAC) has a good short-term clinical efficacy in repairing articular cartilage defects, but the proliferation ability of PJAC and the biological characteristics of transplanted cells after transplantation are still unclear. Purpose To study the cartilage proliferation ability of PJAC in repairing full-thickness cartilage defects and the reasons for proliferation to provide experimental evidence for its clinical application. Study design Controlled laboratory study. Methods Twenty Guizhou minipigs were randomly divided into the experimental group and control group. In all minipigs, an 8-mm cylindrical full-thickness cartilage defect was created in the femoral trochlea of one knee. The experimental group received PJAC transplantation from five juvenile donors of Guizhou minipigs (PJAC group; n = 10) and the control group received transplantation of autologous cartilage chips (ACC group; n = 10). Both groups were followed at 1 and 3 months after surgery, immunohistochemical evaluation of the tissue sections Ki-67 and Lin28 was conducted, the positive rate was calculated according to the staining, and the proliferation ability of PJAC was analyzed. Results All 20 Guizhou minipigs were followed, and there was no infection or incision healing disorder after surgery. By Ki-67 and Lin28 immunohistochemical tests, the positive rate of Ki-67 was 88.9 ± 0.2% in the PJAC group and 28.3 ± 3.6% in the ACC group at 1 month, and the difference was statistically significant (P P P P Conclusion A large animal model was established with Guizhou minipigs, and the expressions of Ki-67 protein and Lin28 protein detected by immunohistochemistry in the repaired transplanted tissue of the PJAC group were stronger than those of adult cartilage. The proliferation of PJAC within 3 months of transplantation was stronger than that of adult cartilage. The enhanced expression of Lin28 may be one of the mechanisms by which PJAC achieved stronger proliferation ability than adult cartilage. PJAC technology has shown good application prospects for repairing cartilage defects.

The high color rendering index (CRI) and doping-free four-emitting-layer (EML) white orangic light-emitting diode (WOLED) with bipolar spacer layer was researched by different emitter sequence arrangements (positive emitter sequence: B-G-O-R, reverse emitter sequence: R-O-G-B). The resulting four-emitting-layer WOLEDs with different sequences show opposite CRI trends when voltage increases, which includes the decreased trend in B-G-O-R sequence and increased trend in R-O-G-B sequence. That leads to WOLEDs with different sequences exhibit the highest CRI at obviously distinguishing luminance, which are CRI of 86 @ 531 cd m−2 in B-G-O-R sequence and CRI of 87 @ 13,340 cd m−2 in R-O-G-B sequence, respectively. Meanwhile, the B-G-O-R and R-O-G-B sequences devices also exhibit a difference in the power efficiency. The different manifestations of CRI and effeciency characteristics are meticulously analyzed by a combined operation of energy transfer mechanism, carrier trap effect and the movement of carrier recombination zone in EML, resulting in a meaningful concept to design high CRI WOLEDs in different application scene.

Co-combustion biomass and coal can effectively reduce the emission of CO2. O2/H2O combustion is regarded as the next generation of oxy-fuel combustion technology. By co-combustion biomass and coal under oxy-fuel condition, the emission of CO2 can be minimized. This work investigates the co-combustion characteristics of single particles from pine sawdust (PS) and bituminous coal (BC) in O2/N2, O2/CO2 and O2/H2O atmospheres at different O2 mole fractions (21%, 30% and 40%). The experiments were carried out in a drop tube furnace (DTF), and a high speed camera was used to record the combustion process of fuel particles. The combustion temperature was measured by a two-color method. The experiments in O2/N2 atmosphere indicate that the particles from pine sawdust and bituminous coal all ignite homogeneously. After replacing H2O for N2, the combustion temperature of volatiles of blended fuel particles decreases, while the combustion temperature of char increases. The ignition delay time in O2/H2O atmosphere is shorter than that in O2/N2 or O2/CO2 atmosphere. The combustion temperature of volatiles of blended fuel particles increases as the mass fraction of bituminous coal increases, while the combustion temperature of char of blended fuel particles is higher than that of biomass or bituminous coal. The ignition delay time of blended fuel particles increases with the increasing mass fraction of bituminous coal, and the experimental ignition delay time of blend fuel particles is shorter than the theoretical one. These reveal a synergy during co-combustion process of pine sawdust and bituminous coal.

Radiotherapy is emerging as an important modality for the local control of pancreatic cancer, but pancreatic cancer cell radioresistance remains a serious concern. Peroxisome proliferator-activated receptor α (PPARα) is a member of the PPAR nuclear hormone receptor superfamily, which can be activated by fibrate ligands. The clinical relevance of PPARα and its biological function in pancreatic cancer radiosensitivity have not been previously described. In this study, we examined PPARα expression in tissue samples of pancreatic cancer patients. We found significantly higher expression of PPARα in pancreatic cancer tissues than in tumor-adjacent tissues and that the PPARα expression level is inversely associated with higher overall patient survival rate. We further observed that PPARα activation by its agonist clofibrate sensitizes pancreatic cancer cells to radiation by modulating cell cycle progression and apoptosis in several pancreatic cancer cell lines. Small interfering RNA-mediated PPARα silencing and PPARα blockade by the antagonist GW6471 abolish the effect of clofibrate on radiosensitization. An in vivo study showed that PANC1 xenografts treated with clofibrate are more sensitive to radiation than untreated xenografts. mRNA profiling by microarray analysis revealed that the expression of PTPRZ1 and Wnt8a, two core components of the β-catenin pathway, is downregulated by clofibrate. Chromatin immunoprecipitation analysis confirmed that clofibrate abrogates the binding of nuclear factor-κB to the PTPRZ1 and Wnt8a promoters, ultimately decreasing Wnt/β-catenin signaling activity, which is associated with radiosensitivity. Overall, we demonstrate that PPARα is overexpressed in pancreatic cancer tissues and clofibrate-mediated PPARα activation sensitizes pancreatic cancer cells to radiation through the Wnt/β-catenin pathway.

A domain name system (DNS) with a hierarchical domain name resolution scheme plays an important role in today's Internet surfing. To protect DNS against cache poisoning attacks is a key issue to achieve Internet security. A lot of defense schemes have been proposed to prevent DNS cache poisoning attacks in recent years. However, most of those schemes cannot get the balance between the security functionality and the performance of the networks. In this paper, in order to improve the performance of the existing security schemes against cache poisoning attacks, we propose a Selective Re-Query Case Sensitive Encoding scheme to efficiently prevent DNS cache poisoning attacks. Our scheme can be easily implemented and deployed only with little modification at the DNS server and can achieve the balance between the security and efficiency. The analysis shows that our scheme can provide strong security functionality with desirable efficiency.

Geological structures often exhibit smooth characteristics away from sharp discontinuities. One aim of geophysical inversion is to recover information about the smooth structures as well as about the sharp discontinuities. Because no specific operator can provide a perfect sparse representation of complicated geological models, hyper-parameter regularization inversion based on the iterative split Bregman method was used to recover the features of both smooth and sharp geological structures. A novel preconditioned matrix was proposed, which counteracted the natural decay of the sensitivity matrix and its inverse matrix was calculated easily. Application of the algorithm to synthetic data produces density models that are good representations of the designed models. The results show that the algorithm proposed is feasible and effective.

The adsorption behaviors of five typical volatile organic compounds (VOCs) onto one commercial activated carbon (CAC) in a fixed bed were investigated in this study. The selected CAC as a model adsorbent has a high surface area of 1099.74 m2 g−1. Moreover, five kinds of typical VOCs, including acetone, ethyl acetate, propyl acetate, butyl acetate, and isopropanol, were chosen as the target pollutants. The adsorption capacities of the above VOCs were 289.8, 389.4, 443.7, 467.4, and 474.3 mg g−1, respectively. The adsorption data were fitted by using two dynamic adsorption models (Boltzmann and Yoon-Nelson) and four kinetic models (pseudo-first-order, pseudo-second-order, Elovich and Banham adsorption rate equation). Compared to other models, the Boltzmann model and the Banham adsorption rate equation could well fit the data of the selected sorption periods. These observations indicated that the fixed bed has a small effect of the mass transfer resistance and a high utilization for the adsorbent. Meanwhile, the Banham adsorption rate equation also could well predict the real condition and the maximum adsorption capacity of the adsorbent. Therefore, the present study clarified the adsorption dynamic behaviors of the selected VOCs onto the CAC in a fixed bed. We believe that the finding of this work is helpful to optimize the design of dynamic adsorption system for the removal of VOCs.

Porphyran is a sulfated polysaccharide extracted from Pyropia, a genus of marine red algae. In this study, the biological activity of porphyran from Pyropia yezoensis as an oral hypolipidemic agent in Institute of Cancer Research (ICR) mice was investigated. Porphyran lowered serum triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol/high-density lipoprotein cholesterol (LDL-C/HDL-C) ratio 28 days after administration. Porphyran at a dose of 200 mg kg−1 d−1 can decrease the percentage of body weight gain (BWG) and serum lipid profiles of mice significantly, similar to Zhibituo (a hypolipidemic drug approved by the China Food and Drug Administration in 2009). The mice that have taken porphyran showed an obvious increase in the fecal TC and TG compared with the blank control group. The liver weight, lipid composition (TG and TC), liver damage index (serum alanine aminotransferase, ALT; aspartate aminotransaminase, AST; and alkaline phosphatase, ALP), and hepatocyte morphology results in mice on a high-fat diet imply that dietary administration of porphyran can alleviate liver damage induced by the diet. Therefore, porphyran may be useful as a functional food additive, hypolipidemic, and liver-protective agent.

Mumps presents a serious threat to public health in China. We conducted a descriptive analysis to identify the epidemiological characteristics of mumps in Shandong Province. Spatial autocorrelation and space-time scan analyses were utilized to detect spatial-temporal clusters. From 2005 to 2014, 115745 mumps cases were reported in Shandong, with an average male-to-female ratio of 1.94. Mumps occurred mostly in spring (32.17% of all reported cases) and in children aged 5 to 9 (40.79% of all reported cases). The Moran’s I test was significant and local indicators of spatial autocorrelation (LISA) analysis revealed significant spatial clusters with high incidence. The results showed that the mid-west of Shandong Province and some coastal regions (Qingdao City and Weihai City) were high-risk areas, particularly in the center of the Jining City and the junction of Dongying City, Binzhou City and Zibo City. The results could assist local and national public health agencies in formulating better public health strategic planning and resource allocation.

Target dimension is important information in underwater target classification. An intrinsic mode characteristic extraction method in underwater cylindrical shell acoustic radiation was studied in this paper based on the mechanism of shell vibration to gain the information about its dimension instead of accurate inversion processing. The underwater cylindrical shell vibration and acoustic radiation were first analyzed using mode decomposition to solve the wave equation. The characteristic of acoustic radiation was studied with different cylindrical shell lengths, radii, thickness, excitation points and fine structures. Simulation results show that the intrinsic mode in acoustic radiation spectrum correlates closely with the geometry dimensions of cylindrical shells. Through multifaceted analysis, the strongest intrinsic mode characteristic extracted from underwater shell acoustic radiated signal was most likely relevant to the radiated source radius. Then, partial information about unknown source dimension could be gained from intrinsic mode characteristic in passive sonar applications for underwater target classification. Experimental data processing results verified the effectiveness of the method in this paper.

Proteolysis of grass carp sarcoplasmic, myofibrillar, and stromal proteins by 5 commercial proteases were studied. Sarcoplasmic and myofibrillar protein could be well hydrolyzed by Alcalase 2.4 L to reach high protein recoveries (PR) (71.86±2.46 and 80.77±3.05%, respectively), while the maximum PR for stromal protein was only 42.83±2.84%. However, stromal hydrolysates, containing mostly 6–10 kDa fraction, exhibited higher ·OH scavenging activities due to its high content of antioxidant-assisting amino acids. Alcalase 2.4 L and pancreatin 6.0, which produced hydrolysates with relative high degree of hydrolysis (DH), were used for further hydrolysis of whole grass carp protein with the assistance of response surface methodology (RSM). The results showed that serine proteases (Alcalase 2.4 L and pancreatin 6.0) could produce sarcoplasmic, myofibrillar, or stromal hydrolysates with relatively high PR, DH, and strong ·OH scavenging activity, which may be used to prepare antioxidant hydrolysates from grass carp.

Lead is a known nephrotoxic element. In this study, primary cultures of rat proximal tubular (rPT) cells were treated with different concentrations of lead acetate (0.25, 0.5 and 1 microM) to investigate its cytotoxic mechanism. A progressive loss in cell viability together with a significant increase in the number of apoptotic and necrotic cells and lactate dehydrogenase release were seen in the experiment. Simultaneously, elevation of reactive oxygen species levels and intracellular [Ca(2+)]i, depletion of mitochondrial membrane potential and intracellular glutathione were revealed during the lead exposure. In addition, apoptotic morphological changes induced by lead exposure in rPT cells were demonstrated by Hoechst 33258 staining. The apoptosis was markedly prevented by N-acetyl-L-cysteine, while the necrosis was not affected. Moreover, catalase and superoxide dismutase activities in the living cells rose significantly. In conclusion, exposure of rPT cells to low-concentration lead led to cell death, mediated by an apoptotic and a necrotic mechanism. The apoptotic death induced by oxidative stress was the chief mechanism. Meanwhile, a group of cells survived lead action, mediated by their ability to activate antioxidant defense systems.

Cadmium (Cd) is a known nephrotoxic element. In this study, the primary cultures of rat proximal tubular (rPT) cells were treated with low doses of cadmium acetate (2.5 and 5 microM) to investigate its cytotoxic mechanism. A progressive loss in cell viability, together with a significant increase in the number of apoptotic and necrotic cells, were seen in the experiment. Simultaneously, elevation of intracellular [Ca(2+)]i and reactive oxygen species (ROS) levels, significant depletion of mitochondrial membrane potential(Delta Psi) and cellular glutathione (GSH), intracellular acidification, and inhibition of Na(+), K(+)-ATPase and Ca(2+)-ATPase activities were revealed in a dose-dependent manner during the exposure, while the cellular death and the apoptosis could be markedly reversed by N-acetyl-L-cysteine (NAC). Also, the calcium overload and GSH depletion were significantly affected by NAC. In conclusion, exposure of rPT cells to low-dose cadmium led to cellular death, mediated by an apoptotic and a necrotic mechanism. The apoptotic death might be the chief mechanism, which may be mediated by oxidative stress. Also, a disorder of intracellular homeostasis induced by oxidative stress and mitochondrial dysfunction is a trigger of apoptosis in rPT cells.

In this study, we explored the operation options for middle cranial fossa arachnoid cysts (MCFAC). One hundred and forty-nine patients who were operated for a symptomatic MCFAC between 1993 and 2006 in our hosptial were analyzed. Follow-up time ranged from 1 y to 14 y (mean=5.4 y). All these patients were divided into three subgroups according to Galassi classification. Long-term outcome and complications were studied respectively. Fenestration (F) resulted in a more favorable long-term outcome and less complication for cysts of types I and II, whereas a favorable outcome was noted in type III patients who underwent cysto-peritoneal shunting (S). We are led to conclude that Fenestration is suitable for cysts of types I and II (Galassi classification), cysto-peritoneal shunting is better for cysts of type III.

In this paper, we proposed a detection-based orthogonal match pursuit (DOMP) algorithm for compressive sensing. Unlike the conventional greedy algorithm, our proposed algorithm does not rely on the priori knowledge of the signal sparsity, which may not be known for some application, e.g., sparse multipath channel estimation. The DOMP runs binary hypothesis on the residual vector of OMP at each iteration, and it stops iteration when there is no signal component in the residual vector. Numerical experiments show the effectiveness of the estimation of signal sparsity as well as the signal recovery of our proposed algorithm.

A capacitively coupled low pressure plasma is used to produce particles by plasma polymerization of various organic precursors. The particles produced by this method are spherical, submicron in diameter, and contain a hollow center. Sixteen organic molecules were tested for the ability to produce hollow particles. Of these, 12 were found to reproducibly result in the formation of hollow particles while the other 4 either produced non-hollow particles or no particles at all under the conditions investigated here. Cyclohexane derivatives and the presence of an aromatic ring correlate strongly with a tendency to form hollow centers. The particle sizes vary from 70 nm to nearly 1 μm and the core diameter is on the average 18 of the particle diameter. The corresponding shell thickness ranges from 24 nm for styrene to about 360 nm for cyclohexane. To explain the formation of hollow centers a mechanism is proposed based on the hypothesis that the solid phase is formed via crosslinking and solidification of viscous drop. This mechanism explains the observed linear relationship between core size and particle size.

An in vivo model of glutamate excitotoxicity in which glutamate is applied to the cortex of rats through a microdialysis probe has been used to investigate the neuroprotective processes initiated by 17 beta-estradiol. Rats were pre-treated with 17 beta-estradiol i.v. before local application of glutamate. The experimental results showed that pre-treatment with 17 beta-estradiol significantly reduced the size of the glutamate-induced lesion. In the microdialysates, the peak of lactate observed immediately after glutamate application was significantly higher and longer lasting after 17 beta-estradiol pre-treatment. The level of extracellular glucose was markedly decreased concomitantly to the increase in lactate, but no difference could be observed with and without 17 beta-estradiol pre-treatment. These suggest a new neuroprotective mechanism of 17 beta-estradiol by activating glutamate-induced lactate production. This effect on lactate production and lesion reduction is estrogen receptor dependent and is abolished totally by estrogen antagonist tamoxifen. It was also demonstrated here that high lactate subserves estrogen neuroprotection during glutamate toxicity.