On-Chip Mirror Enhanced Multiphoton Upconversion Super-Resolution Microscopy.

Multiphoton upconversion super-resolution microscopy (MPUM) is a promising imaging modality, which can provide increased resolution and penetration depth by using nonlinear near-infrared emission light through the so-called transparent biological window. However, a high excitation power is needed to achieve emission saturation, which increases phototoxicity. Here, we present an approach to realize the nonlinear saturation emission under a low excitation power by a simply designed on-chip mirror. The interference of the local electromagnetic field can easily confine the point spread function to a specific area to increase the excitation efficiency, which enables emission saturation under a lower excitation power. With no additional complexity, the mirror assists to decrease the excitation power by 10-fold and facilities the achievement of a lateral resolution around 35 nm, 1/28th of the excitation wavelength, in imaging of a single nanoparticle on-chip. This method offers a simple solution for super-resolution enhancement by a predesigned on-chip device.

Metabolome profiling of plasma reveals different metabolic responses to acute cold challenge between Inner-Mongolia Sanhe and Holstein cattle.

Low-temperature conditions influence cattle productivity and survivability. Understanding the metabolic regulations of specific cattle breeds and identifying potential biomarkers related to cold challenges are important for cattle management and optimization of genetic improvement programs. In this study, 28 Inner-Mongolia Sanhe and 22 Holstein heifers were exposed to -25°C for 1 h to evaluate the differences in metabolic mechanisms of thermoregulation. In response to this acute cold challenge, altered rectal temperature was only observed in Holstein cattle. Further metabolome analyses showed a greater baseline of glycolytic activity and mobilization of AA in Sanhe cattle during normal conditions. Both breeds responded to the acute cold challenge by altering their metabolism of volatile fatty acids and AA for gluconeogenesis, which resulted in increased glucose levels. Furthermore, Sanhe cattle mobilized the citric acid cycle activity, and creatine and creatine phosphate metabolism to supply energy, whereas Holstein cattle used greater AA metabolism for this purpose. Altogether, we found that propionate and methanol are potential biomarkers of acute cold challenge response in cattle. Our findings provide novel insights into the biological mechanisms of acute cold response and climatic resilience, and will be used as the basis when developing breeding tools for genetically selecting for improved cold adaptation in cattle.

S-MAT: Semantic-Driven Masked Attention Transformer for Multi-Label Aerial Image Classification.

Multi-label aerial scene image classification is a long-standing and challenging research problem in the remote sensing field. As land cover objects usually co-exist in an aerial scene image, modeling label dependencies is a compelling approach to improve the performance. Previous methods generally directly model the label dependencies among all the categories in the target dataset. However, most of the semantic features extracted from an image are relevant to the existing objects, making the dependencies among the nonexistant categories unable to be effectively evaluated. These redundant label dependencies may bring noise and further decrease the performance of classification. To solve this problem, we propose S-MAT, a Semantic-driven Masked Attention Transformer for multi-label aerial scene image classification. S-MAT adopts a Masked Attention Transformer (MAT) to capture the correlations among the label embeddings constructed by a Semantic Disentanglement Module (SDM). Moreover, the proposed masked attention in MAT can filter out the redundant dependencies and enhance the robustness of the model. As a result, the proposed method can explicitly and accurately capture the label dependencies. Therefore, our method achieves CF1s of 89.21%, 90.90%, and 88.31% on three multi-label aerial scene image classification benchmark datasets: UC-Merced Multi-label, AID Multi-label, and MLRSNet, respectively. In addition, extensive ablation studies and empirical analysis are provided to demonstrate the effectiveness of the essential components of our method under different factors.

Size-Dependent Nickel-Based Electrocatalysts for Selective CO2 Reduction.

Closing the anthropogenic carbon cycle by converting CO2 into reusable chemicals is an attractive solution to mitigate rising concentrations of CO2 in the atmosphere. Herein, we prepared Ni metal catalysts ranging in size from single atoms to over 100 nm and distributed them across N-doped carbon substrates which were obtained from converted zeolitic imidazolate frameworks (ZIF). The results show variance in CO2 reduction performance with variance in Ni metal size. Ni single atoms demonstrate a superior Faradaic efficiency (FE) for CO selectivity (ca. 97 % at -0.8 V vs. RHE), while results for 4.1 nm Ni nanoparticles are slightly lower (ca. 93 %). Further increase the Ni particle size to 37.2 nm allows the H2 evolution reaction (HER) to compete with the CO2 reduction reaction (CO2 RR). The FE towards CO production decreases to under 30 % and HER efficiency increase to over 70 %. These results show a size-dependent CO2 reduction for various sizes of Ni metal catalysts.

Effect of photobiomodulation on neural differentiation of human umbilical cord mesenchymal stem cells.

Photobiomodulation therapy (PBMT) can enhance the mesenchymal stem cell (MSC) proliferation, differentiation, and tissue repair and can therefore be used in regenerative medicine. The objective of this study is to investigate the effects of photobiomodulation on the directional neural differentiation of human umbilical cord mesenchymal stem cells (hUC-MSCs) and provide a theoretical basis for neurogenesis. hUC-MSCs were divided into control, inducer, laser, and lasers combined with inducer groups. A 635-nm laser and an 808-nm laser delivering energy densities from 0 to 10 J/cm2 were used in the study. Normal cerebrospinal fluid (CSF) and injured cerebrospinal fluid (iCSF) were used as inducers. The groups were continuously induced for 3 days. Cellular proliferation was evaluated using MTT. The marker proteins nestin (marker protein of the neural precursor cells), NeuN (marker protein of neuron), and GFAP (glial fibrillary acidic protein, marker proteins of glial cells) were detected by immunofluorescence and western blot. We found that irradiation with 635-nm laser increased cell proliferation, and that with 808 nm laser by itself and combined with cerebrospinal fluid treatment generated significant neuron-like morphological changes in the cells at 72 h. Nestin showed high positive expression at 24 h in the 808 nm group. The expression of GFAP increased in the 808-nm combined inducer group at 24 h but decreased at 72 h. The expression of neuN protein increased only at 72 h in both the 808-nm combined inducer group and inducer group. We concluded that 808 nm laser irradiation could help CSF to induce neuronal differentiation of hUC-MSCs in early stage and tend to change to neuron rather than glial cells.

The Systemic Activation of Programmed Death 1-PD-L1 Axis Protects Systemic Lupus Erythematosus Model from Nephritis.

BACKGROUND: Systemic lupus erythematosus (SLE) is characterized by abnormal activated T cells, autoreactive B cells, and massive cytokines. The CD4+ T cells determined B-cells differentiation and cytokines production. The programmed death 1 (PD-1) is the checkpoint immunoinhibitory receptor of activated T cells, and its engagement could exhaust T cells. In this study, we investigated the role of PD-1 systemic engagement with PD-L1-Ig in lupus-like nephritis in SLE mice. METHODS: The murine PD-L1-Ig was injected into SLE-prone mice. The proteinuria and survival ratio were monitored. The production of anti-dsDNA autoantibodies and cytokines in serum were measured by enzyme-linked immunosorbent assay. The cytokine-producing T cells (interferon-γ, IFN-γ and IL-17α) in kidney and spleen were detected with flowcytometry. The pathological evaluation of the Ig deposition in the glomeruliand was determined with immunofluorescence. Lymphocytes in 24-h urine were detected with flowcytometry. RESULTS: The systemic administration of PD-L1-Ig activated PD-1-PD-L1 axis of CD4+ T lymphocytes, suppressed Th17 formation in many organs, including the spleen and the kidney, demolished abnormal production of cytokines (IFN-γ, IL-17, and IL-10) and anti-dsDNA autoantibodies in serum, inhibited immunoglobulin G deposition in the glomeruli with the decrease of proteinuria, and activated T cells in urine. Accordingly, the systemic conjugation of PD-L1-PD-1 impaired renal autoimmune injure and prolonged survival time. CONCLUSION: Our research demonstrated that the protective function of systemic activation of PD-1-PD-L1 axis with PD-L1-Ig attenuates the nephritis in SLE-prone mice, which facilitates us to understand the suppressive function of PD-1-PD-L1 axis in the pathogenesis and progress of the lupus nephritis, and to explore a possible effective therapeutic strategy to SLE.

Polymorphisms in epigenetic and meat quality related genes in fourteen cattle breeds and association with beef quality and carcass traits.

Improvement for carcass traits related to beef quality is the key concern in beef production. Recent reports found that epigenetics mediates the interaction of individuals with environment and nutrition. The present study was designed to analyze the genetic effect of single nucleotide polymorphisms (SNPs) in seven epigenetic-related genes (DNMT1, DNMT3a, DNMT3b, DNMT3L, Ago1, Ago2, and HDAC5) and two meat quality candidate genes (CAPN1 and PRKAG3) on fourteen carcass traits related to beef quality in a Snow Dragon beef population, and also to identify SNPs in a total of fourteen cattle populations. Sixteen SNPs were identified and genotyped in 383 individuals sampled from the 14 cattle breeds, which included 147 samples from the Snow Dragon beef population. Data analysis showed significant association of 8 SNPs within 4 genes related to carcass and/or meat quality traits in the beef populations. SNP1 (13154420A>G) in exon 17 of DNMT1 was significantly associated with rib-eye width and lean meat color score (p<0.05). A novel SNP (SNP4, 76198537A>G) of DNMT3a was significantly associated with six beef quality traits. Those individuals with the wild-type genotype AA of DNMT3a showed an increase in carcass weight, chilled carcass weight, flank thicknesses, chuck short rib thickness, chuck short rib score and in chuck flap weight in contrast to the GG genotype. Five out of six SNPs in DNMT3b gene were significantly associated with three beef quality traits. SNP15 (45219258C>T) in CAPN1 was significantly associated with chuck short rib thickness and lean meat color score (p<0.05). The significant effect of SNP15 on lean meat color score individually and in combination with each of other 14 SNPs qualify this SNP to be used as potential marker for improving the trait. In addition, the frequencies of most wild-type alleles were higher than those of the mutant alleles in the native and foreign cattle breeds. Seven SNPs were identified in the epigenetic-related genes. The SNP15 in CAPN1 could be used as a powerful genetic marker in selection programs for beef quality improvement in the Snow Dragon Beef population.

A strategy for the preparation of super-hydrophilic molybdenum disulfide composites applied to remove uranium from wastewater.

Due to the radioactivity of uranium, the discharged nuclear wastewater not only causes certain damage to the ecology, but also causes certain harm to human life and health. Adsorption is considered to be one of the most effective ways to remove uranium. In this paper, a kind of MoS2 adsorbent was prepared by the solid phase synthesis method and functionalized with NiCo-LDH. The raw materials of MoS2 are cheap and easy to obtain, and the preparation conditions are simple, and large quantities can be obtained without limitations. MoS2 functionalized with NiCo-LDH provides more adsorption sites for the adsorbent and at the same time improves the hydrophilicity of the adsorbent, so that the active sites can fully combine with uranyl ions. The maximum adsorption capacity of the Langmuir isothermal adsorption model is 492.83 mg g-1. The selective adsorption capacity of uranium can reach 76.12% in the multi-ion coexistence system. By analyzing the adsorption mechanism with FT-IR and XRD, it is believed that on the one hand, UO22+ forms a covalent bond with Mo in MoS2 and coordinates with S on the surface of MoS2. On the other hand, UO22+ enters the NiCo-LDH layer for ion exchange with NO3- and coordinates with -OH on the surface of NiCo-LDH. The successful preparation of the MoS2/NiCo-LDH composite provides a certain application prospect for the uranium adsorption field.

[Establishment of the detection method for two causative genes of cattle arachnomelia syndrome].

Arachnomelia syndrome (AS) is a recessive inherited disease in cattle. Although the arachnomelia phenotypes are virtually identical in Brown Swiss and Simmental cattle, the causative mutation are different, which are a 1 bp insertion c.363-364insG in the sulfite oxidase (SUOX) gene and a 2 bp deletion c.1224_1225delCA in the molybdenum cofactor syn-thesis step 1 (MOCS1) gene, respectively. In the current study, combining fluorescence PCR with capillary electrophoresis technology, an automatic fluorescence method was established, which could detect the two causative loci rapidly and cor-rectly with a single reaction. Samples from 51 Simmental bulls, 80 cows mated artificially using semen of Simmental bulls and their resulted 106 progeny, together with 55 Xinjiang Brown were collected and used for validation of the newly de-signed methods. Our results have laid a foundation for screening AS disease causing mutations in Chinese cattle.

Using DeepContact with Amira graphical user interface.

DeepContact is a deep learning software for high-throughput quantification of membrane contact site (MCS) in 2D electron microscopy images. This protocol will guide users through incorporating available DeepContact models in Amira's artificial intelligence module, thereby allowing invoking of DeepContact functions in organelle segmentation and quantifying of MCS with a user-friendly graphical user interface of Amira software. For complete details on the use and execution of this protocol, please refer to Liu et al. (2022).1.

Solar engineering of wastewater treatment for full mineralization of organic pollutants.

Full mineralization of organic pollutants is a tough task with existing technologies. Even if all conventional energies and extremes are exhausted, high-temperature wastewater treatment is not worth the loss from the perspective of energy. Solar engineering holds promise for the full mineralization of organic pollutants to tackle the global fossil energy shortage. Here, we report solar engineering for full mineralization and efficient solar utilization. The solar energies and spectrum were fully utilized to initiate the solar heat and solar electricity. Two energies were applied to trigger the thermochemical and electrochemical oxidation of the organic pollutants. Our study bridges the gap between the energy and environment towards efficient solar utilization and effective water treatment. As a proof-of-concept study, this demonstrates a solar engineering of full phenol mineralization in wastewater. A record phenol mineralization rate was achieved to reach an oxidation rate of 98% and COD of 93% under a constant current density of 50mA/cm2 at 150°C. UV and HPLC were used to detect the intermediate products during variable time intervals. The results showed that the intermediate products are composed of maleic acid, hydroquinone and p-benzoquinone. In the extreme high temperature (90°C), the solar oxidation time and pathway are greatly altered. The reaction rate constant at 150°C is about 11 times than that at 90°C. More solar heat significantly reduces the activated energy of the pollutant oxidation and lowers the potential of electrolysis.

Efficient capture of uranium by a hydroxyapatite-modified polyethyleneimine@carbon nanotube composite from radioactive nuclear waste.

The toxicity and radioactivity of uranium (U)-containing wastewater pose a serious threat to the environment of humans, animals, and plants. It is necessary to remove U from contaminated wastewater. With high adsorption capacity and fast adsorption rate, a composite CNT-P/HAP, which comprises carbon nanotubes (CNT) modified with polyethyleneimine (PEI), was functionalized further by hydroxyapatite (HAP) using the hydrothermal method. Adsorption experiments indicated that the optimal performance for CNT-P/HAP was 1330.64 mg g-1 of adsorption capacity and 40 min of adsorption equilibrium at a pH of 3. In addition, the adsorption capacity of CNT-P/HAP was over 2 times that of HAP at a pH of 7. The synergistic effect in both synthesis and adsorption gave CNT-P/HAP an excellent adsorption capacity for U. The XRD and FT-IR analysis indicated that the adsorption mechanism of CNT-P/HAP for U is decided by the pH of the solution. CNT-P/HAP could be used in multiple conditions to remediate U-containing wastewater.

[Plasma D-dimer changes and prognostic implication in severe acute pancreatitis].

OBJECTIVE: To study the role of plasma D-dimer in human severe acute pancreatitis (SAP) and its relationship with disease severity. METHODS: A prospective study was performed. From February 2010 to June 2011, plasma concentration of D-dimer and the results of other routine laboratory tests were measured in 32 SAP inpatients at admission immediately and 24, 48, 72 hours after admission. Ranson scores were also recorded. The relationship between plasma concentration of D-dimer and the results of other routine laboratory tests, Ranson scores were analyzed, and so did the relationship between plasma concentration of D-dimer and severity of patient's condition. RESULTS: (1) There were no obvious changes for plasma concentration of D-dimer and the results of other routine laboratory index in 32 SAP inpatients at each time points after admission. (2) Plasma concentration of D-dimer of SAP was positively related to white blood count (WBC), creatinine (Cr), prothrombin time (PT) and activated partial thromboplastin time (APTT) and negatively related to hematocrit (Hct), albumin and calcium (P<0.05 or P<0.01). Plasma concentration of D-dimer of SAP at 48 hours after admission had positive relationship with Ranson scores (r=0.729, P=0.001). (3) Plasma concentration of D-dimer of SAP inpatients in CT grade D, E stage were significantly higher than that in CT grade B, C stage (1.18±0.02 mg/L, 1.23±0.01 mg/L vs. 0.90±0.02 mg/L, 0.93±0.01 mg/L, all P<0.05). (4) Plasma concentration of D-dimer of SAP in inpatients with multiple organ failure (MOF) at 24 hours and 48 hours were significantly higher than that in inpatients without MOF (24 hours: 1.26±0.02 mg/L vs. 0.93±0.02 mg/L, 48 hours:1.25±0.02 mg/L vs. 0.93±0.02 mg/L, both P<0.05). CONCLUSION: Plasma concentration of the D-dimer is significantly increased in SAP patients, and is related to the severity. The first plasma concentration of D-dimer of SAP after admission can well reflect severity of patient's condition.

microRNA-145-5p attenuates acute lung injury via targeting ETS2.

The protective effect of microRNA (miR)-145-5p in acute lung injury (ALI) has been discovered previously. Thus, in this study, we attempted to further investigate the mechanism of miR-145-5p in ALI through the downstream E26 transformation-specific proto-oncogene 2 (ETS2)/transforming growth factor ß1 (TGF-ß1)/Smad pathway. A lipopolysaccharide (LPS)-induced ALI rat model was established. The expression of miR-145-5p in ALI rat lung tissues was up-regulated. Afterward, pathological damage in the lung tissue, the wet/dry (W/D) ratio, apoptosis, and serum inflammatory factor contents were observed. miR-145-5p, ETS2, TGF-ß1, Smad2/3, and phosphorylated Smad2/3 levels were measured in rats. miR-145-5p expression was down-regulated, ETS2 expression was up-regulated, and the TGF-ß1/Smad pathway was activated in LPS-exposed rats. Overexpression of miR-145-5p inactivated the TGF-ß1/Smad pathway and attenuated ALI, as reflected by relieved pathological damage, a decreased W/D ratio, reduced apoptosis, and suppressed inflammatory response. In contrast, loss of miR-145-5p or elevated ETS2 levels worsened ALI and activated the TGF-ß1/Smad pathway. Moreover, elevation of ETS2 diminished miR-145-5p-mediated protection against ALI. Evidently, miR-145-5p negatively regulates ETS2 expression and inactivates the TGF-ß1/Smad pathway to ameliorate ALI in rats.

Treatment and recycling of acidic fracturing flowback fluid.

Acidic fracturing flowback fluid (AFFF) has the characteristics of low pH value, high chemical oxygen demand (COD), high corrosiveness and complex components. Surface discharge without treatment may contaminate the environment. However, wastewater treatment after centralized transportation has potential safety risks and requires high costs. In this study, we confirmed that calcium and magnesium could affect cross-linking property of fracturing fluid prepared by flowback fluid, and conducted a three-step process, two-stage filtration, chemical precipitation, and flocculation precipitation, on AFFF. After treatment, we made new hydraulic fracturing fluid using the treated acidic flowback fluid as base fluid and compared the quality of the new hydraulic fracturing fluid to the ones used freshwater as base fluid. The results showed when concentration of sodium carbonate, polyaluminium chloride (PAC), polyacrylamide (PAM) were 145, 1000, and 20 mg/L respectively, the treatment result was optimal. After treatment, the oil content of AFFF decreased from 7400 to 26.53 mg/L and suspended solids (SS) from 650 to 18.24 mg/L, and the removal rate of high-valence metal ions was more than 99%. The rheological properties and viscoelasticity of new fracturing fluid prepared by the treated AFFF were similar to the ones prepared by freshwater, which met the requirements of high temperature and shear resistance for ultra-deep wells.

Solar Boosting Pollutant Removal plus Hydrogen Production by Lifting-Heat and Lowering-Potential Chemical Synergy.

Solar-boosted oxidation plus hydrogen production for pollutant removal in wastewater, driven by a high thermal and low-potential electrochemical combination, is facilitated and demonstrated from theory to experiments. One sun fully offers both thermal and electrical energy powered thermo- and electrochemistry for pollutant oxidation. Solar thermal action provides high temperatures for the activation of the pollutant molecules to gear up for solar-driven electrochemical oxidation. Taking wastewater containing phenol as an example, the cyclic voltammetry (CV) curves display two redox processes at less than 100 °C, while only one redox process of single oxidation of phenol appears at more than 100 °C. The oxidation of phenol is accompanied by an efficient evolution of hydrogen, in which the yield of 0.627 mL at 30 °C is increased to 2.294 mL at 210 °C. The phenol removal is enhanced to 80.50% at 210 °C. Tracking the reaction progress shows that small molecular organic acids are detected as the only intermediate at the high temperatures, which suggests the easy realization of full mineralization. The kinetic reaction of the phenol oxidation is fitted to the first order with an increase of the rate constant of 10 times compared with that at low temperatures. Solar engineering of oxidation of organic pollutants not only solves the issue of energy demand for the tough wastewater treatment but also realizes fast and efficient oxidation of organic pollutants. This study opens up new avenues to achieve solar wastewater treatment and simultaneous hydrogen production.

Development and application of arachnomelia syndrome genetic detection in four Chinese dual-purpose cattle populations.

Arachnomelia syndrome (AS) is an autosomal recessive hereditary disorder in cattle, and affected calves are usually stillborn and characterized by complex anomalies. Therefore, identification of the carrier animals based on genetic tests is important for the control and elimination of this defect. The aim of this study was to build an effective workflow to routinely screen the AS mutations in bovine MOSC1 and SUOX genes and determine individuals carrying the AS mutations in four Chinese cattle populations. By combining the fluorescence-labeled PCR and capillary electrophoresis, we established a convenient and cost-effective workflow to detect two AS casual mutations simultaneously. Sanger sequencing was further used as a validation criterion and showed that 100% of the tests (37/37) had consistent results with genotype calls determined by our established workflow. Then, 582 bulls and 1-926 cows from Chinese dual-purpose cattle populations of Simmental, Sanhe, Shuxuan, and Xinjiang Brown were subjected to AS detection. The results showed that four bulls and 11 cows in the Simmental population, and six bulls and six cows in the Sanhe population were identified as AS carriers with the MOCS1 mutation c.1224_1225delCA. However, no animal was found to carry the c.363_364insG mutation in the SUOX gene. The frequencies of AS carriers were 1.08% and 1.65% in the Simmental and Sanhe populations, respectively, with a frequency of 1.076% in four populations. The pedigree analysis found that all carriers could be traced back to a common ancestor, the German Simmental sire ROMEL. Those findings suggested that this genetic defect spread into China mainly through the wide use of ROMEL. In conclusion, the occurrence of AS has not had a wide impact on the Chinese cattle industry; however, a screening system and mating strategy should be employed to gradually eliminate this recessive gene from the Chinese dual-purpose cattle population.

Investigating the Short-Term Effects of Cold Stress on Metabolite Responses and Metabolic Pathways in Inner-Mongolia Sanhe Cattle.

Inner-Mongolia Sanhe cattle are well-adapted to low-temperature conditions, but the metabolic mechanisms underlying their climatic resilience are still unknown. Based on the 1H Nuclear Magnetic Resonance platform, 41 metabolites were identified and quantified in the serum of 10 heifers under thermal neutrality (5 °C), and subsequent exposure to hyper-cold temperature (-32 °C) for 3 h. Subsequently, 28 metabolites were pre-filtrated, and they provided better performance in multivariate analysis than that of using 41 metabolites. This indicated the need for pre-filtering of the metabolome data in a paired experimental design. In response to the cold exposure challenge, 19 metabolites associated with cold stress response were identified, mainly enriched in "aminoacyl-tRNA biosynthesis" and "valine, leucine, and isoleucine degradation". A further integration of metabolome and gene expression highlighted the functional roles of the DLD (dihydrolipoamide dehydrogenase), WARS (tryptophanyl-tRNA synthetase), and RARS (arginyl-tRNA synthetase) genes in metabolic pathways of valine and leucine. Furthermore, the essential regulations of SLC30A6 (solute carrier family 30 (zinc transporter), member 6) in metabolic transportation for propionate, acetate, valine, and leucine under severe cold exposure were observed. Our findings presented a comprehensive characterization of the serum metabolome of Inner-Mongolia Sanhe cattle, and contributed to a better understanding of the crucial roles of regulations in metabolites and metabolic pathways during cold stress events in cattle.

Electrochemical preparation and properties of a Mg-Li-Y alloy via co-reduction of Mg(ii) and Y(iii) in chloride melts.

Mg-Li based alloys have been widely used in various fields. However, the widespread use of Mg-Li based alloys were restricted by their poor properties. The addition of rare earth element in Mg-Li can significantly improve the properties of alloys. In the present work, different electrochemical methods were used to investigate the electrochemical behavior of Y(iii) on the W electrode in LiCl-KCl melts and LiCl-KCl-MgCl2 melts. In LiCl-KCl melts, typical cyclic voltammetry was used to study the electrochemical mechanism and thermodynamic parameters for the reduction of Y(iii) to metallic Y. In LiCl-KCl-MgCl2 melts, the formation mechanism of Mg-Y intermetallic compounds was investigated, and the results showed that only one kind of Mg-Y intermetallic compound was formed under our experimental conditions. Mg-Li-Y alloys were prepared via galvanostatic electrolysis, and XRD and SEM equipped with EDS analysis were used to analyze the samples. Because of the restrictions of EDS analysis, ICP-AES was used to analyze the Li content in Mg-Li-Y alloys. The microhardness and Young's modulus of the Mg-Li-Y alloys were then evaluated.

Comparison of actual and simulated tumoricidal effects induced by photodynamic therapy.

OBJECTIVES: Numerous studies employ mathematical methods, such as Monte Carlo simulation, to predict the tumor killing effects of photodynamic therapy (PDT) by simulating optical propagation, photosensitizer distribution, and oxygen distribution. Whether these models faithfully reflect tumor killing is unknown, and model validation using tumor cross sections in these studies is usually insufficient to answer this question. To fill this gap in our knowledge, we employed a mouse model of breast cancer to determine the spatiotemporal effects of PDT using direct histopathological and biochemical analyses of whole tumors. METHODS: We prepared approximately 700 5-µm-thick serial sections of breast tumors of syngeneic mice treated with PDT employing the photosensitizer photocarcinorin (PsD-007, a second-generation photosensitizer developed in China). Three adjoining sections were subjected to hematoxylin and eosin staining to assess necrosis, the TUNEL assay to evaluate apoptosis, and CD31 staining to detect angiogenesis, respectively. We then generated a three-dimensional (3D) reconstruction of the tumor to evaluate these processes. We simultaneously used the Monte Carlo method to develop a model of light distribution throughout the tumor to evaluate the actual and simulated tumor killing effects induced by PDT. RESULTS: Tumor necrosis decreased exponentially as a function of distance from the source of illumination, while the distributions of apoptosis and neovascularization were independent of light distribution. Most apoptosis occurred in the lower layers (3000-4000 µm) of the tumor where the light intensity was too low to excite the photosensitizer. Neovascularization occurred at depths ranging from 2500 to 3500 µm. These analyses provided a 3D view of how a tumor is destroyed using PDT. CONCLUSIONS: Although the optical distribution model predicted tumor necrosis caused by PDT, it was ineffective in predicting the sites of apoptosis and vascular destruction. Mathematical modeling is limited in its capabilities required to gain a comprehensive understanding of the spatiotemporal events associated with PDT. The mouse model developed here will serve as a platform for detailed direct histopathological, biochemical, and molecular genetic analyses of the effects of PDT, which will facilitate the development of optimized treatment strategies.