Energy Consumption Modeling of Stereolithography-Based Additive Manufacturing Toward Environmental Sustainability

Additive manufacturing (AM), also referred as three-dimensional printing or rapid prototyping, has been implemented in various areas as one of the most promising new manufacturing technologies in the past three decades. In addition to the growing public interest in developing AM into a potential mainstream manufacturing approach, increasing concerns on environmental sustainability, especially on energy consumption, have been presented. To date, research efforts have been dedicated to quantitatively measuring and analyzing the energy consumption of AM processes. Such efforts only covered partial types of AM processes and explored inadequate factors that might influence the energy consumption. In addition, energy consumption modeling for AM processes has not been comprehensively studied. To fill the research gap, this article presents a mathematical model for the energy consumption of stereolithography (SLA)-based processes. To validate the mathematical model, experiments are conducted to measure the real energy consumption from an SLA-based AM machine. The design of experiments method is adopted to examine the impacts of different parameters and their potential interactions on the overall energy consumption. For the purpose of minimization of the total energy consumption, a response optimization method is used to identify the optimal combination of parameters. The surface quality of the product built using a set of optimal parameters is obtained and compared with parts built with different parameter combinations. The comparison results show that the overall energy consumption from SLA-based AM processes can be significantly reduced through optimal parameter setting, without observable product quality decay

Tanshinone IIA reduces SW837 colorectal cancer cell viability via the promotion of mitochondrial fission by activating JNK-Mff signaling pathways

Abstract Background Mitochondrial homeostasis has been increasingly viewed as a potential target of cancer therapy, and mitochondrial fission is a novel regulator of mitochondrial function and apoptosis. The aim of our study was to determine the detailed role of mitochondrial fission in SW837 colorectal cancer cell viability, mobility and proliferation. In addition, the current study also investigated the therapeutic impact of Tanshinone IIA (Tan IIA), a type of anticancer adjuvant drug, on cancer mitochondrial homeostasis. Results The results of our data illustrated that Tan IIA promoted SW837 cell death, impaired cell migration and mediated cancer proliferation arrest in a dose-dependent manner. Functional investigation exhibited that Tan IIA treatment evoked mitochondrial injury, as witnessed by mitochondrial ROS overproduction, mitochondrial potential collapse, antioxidant factor downregulation, mitochondrial pro-apoptotic protein upregulation, and caspase-9-dependent apoptotic pathway activation. Furthermore, we confirmed that Tan IIA mediated mitochondrial damage by activating mitochondrial fission, and the inhibition of mitochondrial fission abrogated the proapoptotic effects of Tan IIA on SW837 cells. To this end, our results demonstrated that Tan IIA modulated mitochondrial fission via the JNK-Mff pathways. The blockade of the JNK-Mff axis inhibited Tan IIA-mediated mitochondrial fission and promoted the survival of SW837 cells. Conclusions Altogether, our results identified mitochondrial fission as a new potential target to control cancer viability, mobility and proliferation. Furthermore, our findings demonstrate that Tan IIA is an effective drug to treat colorectal cancer by activating JNK-Mff-mitochondrial fission pathways

Total Synthesis and Structural Determination of the Dimeric Tetrahydroxanthone Ascherxanthone A

The first total synthesis of the dimeric tetrahydroxanthone ascherxanthone A has been accomplished. This synthetic strategy features (1) enantioselective intramolecular allylic C–H oxidation to construct a core chiral chromane, (2) intramolecular aldol reaction/dehydration to form the enone group, and (3) intermolecular Suzuki–Miyaura coupling to connect two monomeric tetrahydroxanthones. This synthetic work allowed us to determine the axial chirality of the 2,2′-biaryl C–C bond and the absolute configuration of the ascherxanthone A. This approach should facilitate the preparation of derivatives and structurally related natural products for medicinal studies

Eurothiocin A and B, Sulfur-Containing Benzofurans from a Soft Coral-Derived Fungus Eurotium rubrum SH-823

Two new sulfur-containing benzofuran derivatives, eurothiocin A and B (1 and 2), along with five known compounds, zinniol (3), butyrolactone I (4), aspernolide D (5), vermistatin (6), and methoxyvermistatin (7), were isolated from the cultures of Eurotium rubrum SH-823, a fungus obtained from a Sarcophyton sp. soft coral collected from the South China Sea. The new compounds (1 and 2) share a methyl thiolester moiety, which is quite rare among natural secondary metabolites. The structures of these metabolites were assigned on the basis of detailed spectroscopic analysis. The absolute configurations of 1 and 2 were determined by comparison of the experimental and calculated electronic circular dichroism (ECD) data. Compounds 1 and 2 exhibited more potent inhibitory effects against α-glucosidase activity than the clinical α-glucosidase inhibitor acarbose. Further mechanistic analysis showed that both of them exhibited competitive inhibition characteristics

Analysis of Conservation Gaps and Landscape Connectivity for Snow Leopard in Qilian Mountains of China

Human modification and habitat fragmentation have a substantial influence on large carnivores, which need extensive, contiguous habitats to survive in a landscape. The establishment of protected areas is an effective way to offer protection for carnivore populations by buffering them from anthropogenic impacts. In this study, we used MaxEnt to model habitat suitability and to identify conservation gaps for snow leopard (Panthera uncia) in the Qilian Mountains of China, and then assessed the impact of highways/railways and their corridors on habitat connectivity using a graph-based landscape connectivity model. Our results indicated that the study area had 51,137 km2 of potentially suitable habitat for snow leopards and that there were four protection gaps outside of Qilian Mountain National Park. The findings revealed that the investigated highway and railway resulted in a decrease in connectivity at a regional scale, and that corridor development might enhance regional connectivity, which strengthens the capacity of central habitat patches to act as stepping stones and improve connections between western and eastern habitat patches. This study emphasized the need for assessing the impact of highways and railways, as well as their role in corridor development, on species’ connectivity. Based on our results, we provide some detailed recommendations for designing protection action plans for effectively protecting snow leopard habitat and increasing habitat connectivity

Structural and biochemical characterization of MCAT from photosynthetic microorganism Synechocystis sp PCC 6803 reveal its stepwise catalytic mechanism

Malonyl-coenzyme A: acyl-carrier protein transacylase (MCAT) catalyzes the transfer of malonyl group from malonyl-CoA to the holo-acyl carrier protein (Holo-ACP), yielding malonyl-ACR The overall reaction has been extensively studied in heterotrophic microorganisms, while its mechanism in photosynthetic autotrophs as well as the stepwise reaction information remains unclear. Here the 2.42 angstrom crystal structure of MCAT from photosynthetic microorganism Synechocystis sp. PCC 6803 is presented. It demonstrates that Arg113, Ser88 and His188 constitute catalytic triad. The second step involved ACPMCAT-malonyl intermediate is speed-limited instead of the malonyl-CoA-MCAT intermediate in the first step. Therefore His87, Arg113 and Ser88 render different contributions for the two intermediates. Additionally, S88T mutant initializes the reaction by H87 deprotonating S88T which is different from the wild type. (C) 2015 Elsevier Inc. All rights reserved

Efficacy and Safety of the Combination Treatment of Rituximab and Dexamethasone for Adults with Primary Immune Thrombocytopenia (ITP): A Meta-Analysis

Objective. To conduct a meta-analysis, assessing the efficacy and safety of the combination treatment of dexamethasone and rituximab for adults with ITP (primary immune thrombocytopenia). Methods. Randomized controlled trials that compared rituximab and dexamethasone combination treatment to dexamethasone monotherapy in the treatment of adults with ITP were collected by searching Pubmed, Embase, Cochrane, China National Knowledge (CNKI), Wanfang database, and Sino Med. We conducted pooled analyses on OR (overall response) rate, CR (complete response) rate, PR (partial response) rate, SR (sustained response) rate, R (relapse) rate, change in Treg cell count (mean [SD]), and AE (adverse event). GRADE pro scale was used to assess the quality of the evidence. Publication bias was assessed with Egger’s test method. Results. A total of 11 randomized controlled trials were eligible for inclusion. The overall efficacy estimates favored combination arm in terms of OR rate at month 3, CR rate at week 4 and month 3, SR rate, and Treg cell count at week 2. Subgroup analysis showed that females obtained a higher OR rate than males did at week 4. No significant difference was found in pooled analysis of relapse rate between combination arm and monotherapy arm. The comparison of serious AE and other AEs showed no significant difference either. A total of 19 outcomes were assessed by GRADE pro software, of which 79% (15/19) was scaled as moderate-to-high level. Publication bias existed in studies on OR at week 4 (P=0.025), CR at week 4 (P=0.017), infection (P=0.006), and rash (P=0.028) of the AEs. Conclusion. Dexamethasone combined with rituximab can provide a better long-term response in the treatment of adults with ITP and will not increase the risk of adverse effects

Investigation of hemostatic effect of Spleen-invigorating, Qi-replenishing and Blood-arresting Formula on simvastatin-induced zebrafish hemorrhage model

Objective: To observe the hemostatic effect of the Spleen-invigorating, Qi-replenishing and Blood-arresting Formula on simvastatin-induced zebrafish hemorrhage model compared with that of the Heat-clearing and Blood-cooling Formula. Methods: AB strain wild type zebrafish were treated with 0.5 μM simvastatin for 24 hours to establish the zebrafish hemorrhage model. Under strictly blind experimental conditions, the zebrafish were then treated with experimental agents in different concentration within the maximum non-lethal dose. The intervention effect of the Spleen-invigorating, Qi-replenishing and Blood-arresting Formula was comprehensively assessed by examining the main observational parameters such as the bleeding reduction rate and hemostatic rate while referring to the additional parameters such as blood flow, improvement rate of blood flow, velocity of movement, improvement rate of motion under spleen-qi deficiency. Results: Hemostatic effect: The bleeding rate and hemostatic rate in the zebrafish were respectively, 30%, 15%, 45%, 40% and 60%, 80%, 40%, 47% when equal concentration of 500 μg/mL, 1000 μg/mL were used. This showed that the experimental herbs B1 was superior to B2 in decreasing the bleeding rate and improving hemostatic effect in the zebrafish. Improvement of blood flow: With equal concentration, the experimental herb B1 was superior to B2 in increasing the blood flow and improvement rate of blood flow in hemorrhagic zebrafish. Promotion of the improvement of motion: With equal concentration of 500 μg/mL and 1000 μg/mL, the experimental herb B1 was superior to B2 in promoting the velocity of motion in the zebrafish and promoting the improvement rate of motion. Conclusion: The manifestations of simvastatin-induced zebrafish hemorrhage are basically similar to that of failure of the spleen to control blood in human beings. The Spleen-invigorating, Qi-replenishing and Blood-arresting Formula has good hemostatic effect on simvastatin-induced hemorrhage in the zebrafish. It also boasts the functions of improving blood flow and velocity of motion in the hemorrhagic zebrafish. Such a conclusion provides the experimental basis for the treatment of the syndrome of failure of the spleen to control blood by this formula

Complete Genome Sequence of Enterobacter cloacae subsp. cloacae Type Strain ATCC 13047 ▿

Enterobacter cloacae is an important nosocomial pathogen. Here, we report the completion of the genome sequence of E. cloacae ATCC 13047, the type strain of E. cloacae subsp. cloacae. Multiple sets of virulence determinant and heavy-metal resistance genes have been found in the genome. To the best of our knowledge, this is the first complete genome sequence of the E. cloacae species

Use of a Serotype-Specific DNA Microarray for Identification of Group B Streptococcus (Streptococcus agalactiae)

Group B Streptococcus (GBS; Streptococcus agalactiae) is an important cause of sepsis and meningitis. Nine GBS serotypes, based on capsular polysaccharide (CPS) antigens, have been described. Their distribution varies worldwide and needs to be monitored to understand the epidemiology of GBS disease and inform the development of vaccines. In this study, we sequenced cpsH of GBS serotype II (cpsHII) and compared it with that of the other eight serotypes to identify serotype-specific regions. We then developed a DNA microarray based on the cpsH gene and used it to test 88 GBS isolates—9 serotype reference strains and 79 clinical isolates—and 7 other bacterial and fungal species which are commonly present in the vagina flora. The microarray was shown to be specific and reproducible. This is the first report of a microarray which can identify the nine GBS serotypes. The use of a microarray has advantages over traditional serotyping methods and will be of practical value in both reference and diagnostic laboratories