60 research outputs found

    Melt flow singularity in linear polyethylene: influence of molar mass, molar mass distribution and carbon-based fillers

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    In the recent past it has been found that a considerable pressure drop occurred during the extrusion of linear polyethylene in the course of capillary flow. The pressure drop resides within a narrow temperature window of one to two degrees Celsius. In this research the hydrodynamic condition and molecular origin of the extrusion window of linear polymer were investigated further. The advantage of the extrusion window, viz. smooth extrudate with less die swell ratio attained at low extrusion pressure and temperature, has potential in industrial applications. However, the extrusion window, corresponding to linear polyethylene (PE) with relatively low polydispersity (<7), has a narrow window temperature interval, circa 1~2°C, thus it could not be applied to industrial scale processing at the industrial scale. To have a fundamental insight and make the process industrially viable, research in this thesis was devoted to broaden the extrusion window to tolerate the thermal fluctuations in conventional processing. To achieve this goal molecular weight dependence of window temperature and flow criticalities is revealed. The hydrodynamic conditions of the extrusion window observed in a rate-controlled rheometer and stick-slip flow studied in a stress-controlled rheometer could be traced back to the same origin, viz. slip flow arises due to the disentanglement of adsorbed chains on capillary wall from free chains in the bulk. Secondly, a dual window effect was uncovered in the course of capillary flow of a bimodal PE, which is consistent with the window temperature dependence on molecular weight. Moreover, it was found that flow induced orientation within the window effect is even less than that observed in steady state flow at a relatively low shear rate. This implies that in the window region only relaxed free chains are extruded through the capillary die and most of the adsorbed chains, which could be disengaged from the entangled melt, remain sticking to the inner capillary wall. This observation is consistent with the hydrodynamic origin of high-surface-energy-die slip flow. Finally, a unimodal linear PE with extremely broad molecular weight distribution, i.e. polydispersity (PDI) is 27, showed a broad window effect, circa 8°C, at an appropriate apparent shear rate. The molecular origin of such a broad window effect is due to its broad molecular weight distribution. These results have further implications for energy efficient processing

    580 species in the 163 plots

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    This file lists the 580 species in the 163 plots used in this paper

    NiCoFe Layered Triple Hydroxides with Porous Structures as High-Performance Electrocatalysts for Overall Water Splitting

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    We report a type of NiCoFe layered triple hydroxides (LTHs) supported on carbon fiber cloth (CFC) (NiCoFe LTHs/CFC) as high-performance electrocatalysts for overall water splitting in alkaline media. The NiCoFe LTHs/CFC as an oxygen evolution reaction (OER) electrocatalyst shows excellent catalytic activity and durability, such as low overpotential of ∼239 mV at 10 mA cm<sup>–2</sup>, small Tafel slope of ∼32 mV dec<sup>–1</sup> and conservation rate of catalytic activity (∼99%) after 12 h of continuous electrolysis at 20 mA cm<sup>–2</sup>. As a hydrogen evolution reaction (HER) electrocatalyst, NiCoFe LTHs/CFC also shows low onset potential, small Tafel slope, and superior durability. The NiCoFe LTHs/CFC-based overall water splitting exhibits a low onset potential (∼1.51 V), a low splitting potential (∼1.55 V) at 10 mA cm<sup>–2</sup>, and excellent durability, and the performance is comparable to that of IrO<sub>2</sub>/Pt-based overall water splitting. This work will open a new avenue toward the development of high-performance and inexpensive layered triple hydroxides electrocatalysts

    DataSheet_1_Assessing the functional vulnerability of woody plant communities within a large scale tropical rainforest dynamics plot.docx

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    IntroductionTropical forests are characterized by intricate mosaics of species-rich and structurally complex forest communities. Evaluating the functional vulnerability of distinct community patches is of significant importance in establishing conservation priorities within tropical forests. However, previous assessments of functional vulnerability in tropical forests have often focused solely on isolated factors or individual disturbance events, with limited consideration for a broad spectrum of disturbances and the responses of diverse species.MethodsWe assessed the functional vulnerability of woody plant communities in a 60-ha dynamic plot within a tropical montane rainforest by conducting in silico simulations of a wide range disturbances. These simulations combined plant functional traits and community properties, including the distribution of functional redundancy across the entire trait space, the distribution of abundance across species, and the relationship between species trait distinctiveness and species abundance. We also investigated the spatial distribution patterns of functional vulnerability and their scale effects, and employed a spatial autoregressive model to examine the relationships between both biotic and abiotic factors and functional vulnerability at different scales.ResultsThe functional vulnerability of tropical montane rainforest woody plant communities was generally high (the functional vulnerability of observed communities was very close to that of the most vulnerable virtual community, with a value of 72.41% on average at the 20m×20m quadrat scale), and they exhibited significant spatial heterogeneity. Functional vulnerability decreased with increasing spatial scale and the influence of both biotic and abiotic factors on functional vulnerability was regulated by spatial scale, with soil properties playing a dominant role.DiscussionOur study provides new specific insights into the comprehensive assessment of functional vulnerability in the tropical rainforest. We highlighted that functional vulnerabilities of woody plant communities and their sensitivity to environmental factors varied significantly within and across spatial scales in the tropical rainforest landscape. Preserving and maintaining the functionality of tropical ecosystems should take into consideration the variations in functional vulnerability among different plant communities and their sensitivity to environmental factors.</p

    The GFP-tagged PCV2 ORF5 up-regulates IL-6, IL-8 and COX-2 expression in PAMs.

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    <p>PAMs were transfected with pEGFP-C1 or pEGFP-ORF5 plasmids and harvested at 48 h post-transfection. (A to C) The effect of PCV2 ORF5 expression on porcine IL-6, IL-8 and COX-2 transcription in cultured PAMs. Total RNA was extracted from cells expressing either GFP alone, GFP-ORF5 fusion, or untransfected cells. Realtime RT-PCR analysis of IL-6, IL-8 and COX-2 mRNA levels were normalized to the corresponding CT value for porcine β-actin mRNA. The results are mean ± SD and representative of three independent experiments. (D to F) The concentrations of IL-6, IL-8 and COX-2 in GFP-ORF5 expressing PAMs or control cells culture supernatants were measured by ELISA. Data are mean ± SD and representative of three independent experiments. *<i>p</i> < 0.05 and **<i>P<</i>0.01 versus the control group.</p

    Identification of Putative ORF5 Protein of Porcine Circovirus Type 2 and Functional Analysis of GFP-Fused ORF5 Protein

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    <div><p>Porcine circovirus type 2 (PCV2) is the essential infectious agent responsible for causing porcine circovirus-associated diseases in pigs. To date, eleven RNAs and five viral proteins of PCV2 have been detected. Here, we identified a novel viral gene within the PCV2 genome, termed ORF5, that exists at both the transcriptional and translational level during productive infection of PCV2 in porcine alveolar macrophages 3D4/2 (PAMs). Northern blot analysis was used to demonstrate that the ORF5 gene measures 180 bp in length and overlaps completely with ORF1 when read in the same direction. Site-directed mutagenesis was used to show that the ORF5 protein is not essential for PCV2 replication. To investigate the biological functions of the novel protein, we constructed a recombinant eukaryotic expression plasmid capable of expressing PCV2 ORF5. The results show that the GFP-tagged PCV2 ORF5 protein localizes to the endoplasmic reticulum (ER), is degraded via the proteasome, inhibits PAM growth and prolongs the S-phase of the cell cycle. Further studies show that the GFP-tagged PCV2 ORF5 protein induces ER stress and activates NF-κB, which was further confirmed by a significant upregulation in IL-6, IL-8 and COX-2 expression. In addition, five cellular proteins (GPNMB, CYP1A1, YWHAB, ZNF511 and SRSF3) were found to interact with ORF5 via yeast two-hybrid assay. These findings provide novel information on the identification and functional analysis of the PCV2 ORF5 protein and are likely to be of benefit in elucidating the molecular mechanisms of PCV2 pathogenicity. However, additional experiments are needed to validate the expression and function of the ORF5 protein during PCV2 infection in vitro before any definitive conclusion can be drawn.</p></div

    Image_1_Clinical efficacy and safety of combined anti-BCMA and anti-CD19 CAR-T cell therapy for relapsed/refractory multiple myeloma: a systematic review and meta-analysis.tif

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    BackgroundThe low rates of durable response against relapsed/refractory multiple myeloma (RRMM) in recent studies prompt that chimeric antigen receptor (CAR)-T cell therapies are yet to be optimized. The combined anti-BCMA and anti-CD19 CAR-T cell therapy showed high clinical efficacy in several clinical trials for RRMM. We here conducted a meta-analysis to confirm its efficacy and safety.MethodsWe collected data from Embase, Web of Science, PubMed, CNKI, Wanfang and Cochrane databases up to April 2023. We extracted and evaluated data related to the efficacy and safety of combined anti-BCMA and anti-CD19 CAR-T cell therapies in RRMM patients. The data was then analyzed using RevMan5.4 and StataSE-64 software. PROSPERO number was CRD42023455002.ResultsOur meta-analysis included 12 relevant clinical trials involving 347 RRMM patients who were treated with combined anti-BCMA and anti-CD19 CAR-T cell therapies. For efficacy assessment, the pooled overall response rate (ORR) was 94% (95% CI: 91%-98%), the complete response rate (CRR) was 50% (95% CI: 29%-71%), and the minimal residual disease (MRD) negativity rate within responders was 73% (95% CI: 66%-80%). In terms of safety, the pooled all-grade cytokine release syndrome (CRS) rate was 98% (95% CI: 97%-100%), grade≥3 CRS rate was 9% (95% CI: 4%-14%), and the incidence of neurotoxicity was 8% (95% CI: 4%-11%). Of hematologic toxicity, neutropenia was 82% (95% CI: 75%-89%), anemia was 71% (95% CI: 53%-90%), thrombocytopenia was 67% (95% CI: 40%-93%) and infection was 42% (95% CI: 9%-76%). The median progression-free survival (PFS) was 12.97 months (95% CI: 6.02-19.91), and the median overall survival (OS) was 26.63 months (95% CI: 8.14-45.11).ConclusionsAs a novel immunotherapy strategy with great potential, the combined anti-BCMA and anti-CD19 CAR-T cell therapy showed high efficacy in RRMM, but its safety needs further improvement. This meta-analysis suggests possible optimization of combined CAR-T therapy.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023455002.</p

    Image_2_Clinical efficacy and safety of combined anti-BCMA and anti-CD19 CAR-T cell therapy for relapsed/refractory multiple myeloma: a systematic review and meta-analysis.tif

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    BackgroundThe low rates of durable response against relapsed/refractory multiple myeloma (RRMM) in recent studies prompt that chimeric antigen receptor (CAR)-T cell therapies are yet to be optimized. The combined anti-BCMA and anti-CD19 CAR-T cell therapy showed high clinical efficacy in several clinical trials for RRMM. We here conducted a meta-analysis to confirm its efficacy and safety.MethodsWe collected data from Embase, Web of Science, PubMed, CNKI, Wanfang and Cochrane databases up to April 2023. We extracted and evaluated data related to the efficacy and safety of combined anti-BCMA and anti-CD19 CAR-T cell therapies in RRMM patients. The data was then analyzed using RevMan5.4 and StataSE-64 software. PROSPERO number was CRD42023455002.ResultsOur meta-analysis included 12 relevant clinical trials involving 347 RRMM patients who were treated with combined anti-BCMA and anti-CD19 CAR-T cell therapies. For efficacy assessment, the pooled overall response rate (ORR) was 94% (95% CI: 91%-98%), the complete response rate (CRR) was 50% (95% CI: 29%-71%), and the minimal residual disease (MRD) negativity rate within responders was 73% (95% CI: 66%-80%). In terms of safety, the pooled all-grade cytokine release syndrome (CRS) rate was 98% (95% CI: 97%-100%), grade≥3 CRS rate was 9% (95% CI: 4%-14%), and the incidence of neurotoxicity was 8% (95% CI: 4%-11%). Of hematologic toxicity, neutropenia was 82% (95% CI: 75%-89%), anemia was 71% (95% CI: 53%-90%), thrombocytopenia was 67% (95% CI: 40%-93%) and infection was 42% (95% CI: 9%-76%). The median progression-free survival (PFS) was 12.97 months (95% CI: 6.02-19.91), and the median overall survival (OS) was 26.63 months (95% CI: 8.14-45.11).ConclusionsAs a novel immunotherapy strategy with great potential, the combined anti-BCMA and anti-CD19 CAR-T cell therapy showed high efficacy in RRMM, but its safety needs further improvement. This meta-analysis suggests possible optimization of combined CAR-T therapy.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023455002.</p

    Sequences of primer pairs used for qRT-PCR.

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    <p>Sequences of primer pairs used for qRT-PCR.</p

    mRNA expression curves.

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    <p>PAMs were infected with wild-type PCV2 (wPCV2), recombinant PCV2 (rPCV2), or a start codon mutant PCV2 (PCV2Δ) at an MOI of 1.0. Cellular total mRNA was harvested at six time points from 12 to 96 h post infection, treated with gDNA eraser and tested by real-time quantitative RT-PCR. (A) Expression of ORF5 mRNAs. (B) Expression of ORF1 mRNAs. (C) Expression of ORF2 mRNAs. (D) Expression of ORF3 mRNAs. (E) Expression of ORF4 mRNAs. Results are presented as group mean cDNA numbers ± SD (n = 3).</p
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