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Proton exchange membranes (PEMs) have emerged as very promising membranes for automotive applications because of their notable proton conductivity at low temperatures. These membranes find extensive utilization in fuel cells. Several polymeric materials have been used, but their application is constrained by their expense and intricate synthetic processes. Affordable and efficient synthetic methods for polymeric materials are necessary for the widespread commercial use of PEM technology. The polymeric combination of hexachlorocyclotriphosphazene (HCCP) and 4,4-diamino-2,2-biphenyldisulfonic acid facilitated the synthesis of PP-(PhSO3H)2, a polyphosphazene with built-in -SO3H moieties. Characterization revealed that it was a porous organic polymer with high stability. PP-(PhSO3H)2 exhibited a proton conductivity of up to 8.24 × 10-2 S cm-1 (SD = ±0.031) at 353 K under 98% relative humidity (RH), which was more than two orders of magnitude higher than that of its -SO3H-free analogue, PP-(Ph)2 (2.32 × 10-4 S cm-1) (SD = ±0.019) under identical conditions. Therefore, for application in a PEM fuel cell, PP-(PhSO3H)2-based matrix-mixed membranes (PP-(PhSO3H)2-MMMs) were fabricated by mixing them with polyacrylonitrile (PAN) in various ratios. The proton conductivity could reach up to 6.11 × 10-2 S cm-1 (SD = ±0.0048) at 353 K and 98%RH, when the weight ratio of PP-(PhSO3H)2 : PAN was 3 : 1, the value of which was comparable with those of commercially available electrolytes used in PEM fuel cells. PP-(PhSO3H)2-MMM (3 : 1) had an extended lifetime of reusability. Using phosphazene and bisulfonated multiple-amine modules as precursors, we demonstrated that a porous organic polymer with a highly effective proton-conductive matrix-mixed membrane for PEM fuel cells could be produced readily by an intuitive polymeric reaction.
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Background: Traditional right hemicolectomy (TRH) is the standard treatment for patients with nonmetastatic right colon cancer. However, the ileocecum, a vital organ with mechanical and immune functions, is removed in these patients regardless of the tumor location. This study aimed to evaluate the technical and oncological safety of laparoscopic ileocecal-sparing right hemicolectomy (LISH). Method: Patients who underwent LISH at two tertiary medical centers were matched 1:2 with patients who underwent TRH by propensity score matching based on sex, age, body mass index, tumor location, and disease stage. Data on surgical and perioperative outcomes were collected. Oncological safety was evaluated in a specimen-oriented manner. Lymph nodes (LNs) near the ileocolic artery (ICA) were examined independently in the LISH group. Disease outcomes were recorded for patients who completed one year of follow-up. Results: In all, 34 patients in the LISH group and 68 patients in the TRH group were matched. LISH added 8 minutes to the dissection of LNs around the ileocolic vessels (groups 201/201d, 202, and 203 LNs), without affecting the total operation time, blood loss, or perioperative adverse event rate. Compared with TRH, LISH had a comparable lymphadenectomy quality, specimen quality, and safety margin while preserving a more functional bowel. The LISH group had no cases of LN metastasis near the ICA. No difference was detected in the recurrence rate at the 1-year follow-up time point between the two groups. Conclusion: In this dual-center study, LISH presented comparable surgical and oncological safety for patients with hepatic flexure or proximal transverse colon cancer.
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Timely and accurate estimation of cotton seedling emergence rate is of great significance to cotton production. This study explored the feasibility of drone-based remote sensing in monitoring cotton seedling emergence. The visible and multispectral images of cotton seedlings with 2 - 4 leaves in 30 plots were synchronously obtained by drones. The acquired images included cotton seedlings, bare soil, mulching films, and PE drip tapes. After constructing 17 visible VIs and 14 multispectral VIs, three strategies were used to separate cotton seedlings from the images: (1) Otsu's thresholding was performed on each vegetation index (VI); (2) Key VIs were extracted based on results of (1), and the Otsu-intersection method and three machine learning methods were used to classify cotton seedlings, bare soil, mulching films, and PE drip tapes in the images; (3) Machine learning models were constructed using all VIs and validated. Finally, the models constructed based on two modeling strategies [Otsu-intersection (OI) and machine learning (Support Vector Machine (SVM), Random Forest (RF), and K-nearest neighbor (KNN)] showed a higher accuracy. Therefore, these models were selected to estimate cotton seedling emergence rate, and the estimates were compared with the manually measured emergence rate. The results showed that multispectral VIs, especially NDVI, RVI, SAVI, EVI2, OSAVI, and MCARI, had higher crop seedling extraction accuracy than visible VIs. After fusing all VIs or key VIs extracted based on Otsu's thresholding, the binary image purity was greatly improved. Among the fusion methods, the Key VIs-OI and All VIs-KNN methods yielded less noises and small errors, with a RMSE (root mean squared error) as low as 2.69% and a MAE (mean absolute error) as low as 2.15%. Therefore, fusing multiple VIs can increase crop image segmentation accuracy. This study provides a new method for rapidly monitoring crop seedling emergence rate in the field, which is of great significance for the development of modern agriculture.
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Introduction: Heavy metal pollution is a major worldwide environmental problem. Many remediation techniques have been developed, these techniques have different performance in different environments. Methods: In this study, soil sampling was conducted in multiple cotton fields in Xinjiang, China, and found that cadmium (Cd) was the most abundant soil heavy metal. Then, to find the most suitable technique for the remediation of Cd pollution in cotton fields, a two-year study was conducted to explore the effects of cotton straw-derived biochar (BC, 3%) and Bacillus-based biofertilizer (BF, 1.5%) on cotton Cd uptake and transport and soil microbial community structure under Cd exposure conditions (soil Cd contents: 1, 2, and 4 mg·kg-1). Results: The results showed that the bioaccumulation coefficients (Cd content of cotton organs / soil available Cd content) of cotton roots, stems, leaves, and buds/bolls reduced by 15.93%, 14.41%, 23.53%, and 20.68%, respectively after the application of BC, and reduced by 16.83%, 17.15%, 22.21%, and 26.25%, respectively after the application of BF, compared with the control (no BC and BF). Besides, the application of BC and BF reduced the transport of Cd from soil to root system, and enhanced the diversity of soil bacterial communities (dominant species: Alphaproteobacteria and Actinobacteria) and the metabolic functions related to amino acid synthesis. It was worth noting that the differential species for BF group vs BC group including Alphaproteobacteria, Gemmatimonadetes, Bacilli, and Vicinamibacteria were associated with the enrichment and transport of Cd, especially the transport of Cd from cotton roots to stems. Discussion: Therefore, the application of BC and BF changed the soil bacterial diversity in Cd-polluted cotton field, and then promoted the transport of Cd in cotton, ultimately improving soil quality. This study will provide a reference for the selection of soil heavy metal pollution remediation techniques in Xinjiang, China.
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AIM: A bridging study of INTRIGUE study to assess the efficacy and safety of ripretinib versus sunitinib as second-line treatment in Chinese GIST patients. METHODS: This was a phase 2, multicenter, randomized, open-label study in China. GIST patients previously treated with imatinib were randomized (1:1) to receive ripretinib 150 mg once daily (QD) by continuous dosing in 42-day cycles or sunitinib 50 mg QD in 42-day cycles (four weeks on/two weeks off). Primary endpoint was progression-free survival (PFS) by independent radiological review (IRR). RESULTS: Between 6 December 2020 and 15 September 2021, 108 patients were randomized to receive ripretinib (n = 54) or sunitinib (n = 54) (all-patient [AP] intention-to-treat [ITT] population). Seventy patients had primary KIT exon 11 mutations (ripretinib, n = 35; sunitinib, n = 35; Ex11 ITT population). By data cut-off (20 July 2022), in AP ITT population, PFS by IRR was comparable between ripretinib and sunitinib arms (HR 0·99, 95 % CI 0·57, 1·69; nominal p = 0·92; median PFS [mPFS] 10·3 vs 8·3 months). In Ex11 ITT population, PFS by IRR was longer for ripretinib than sunitinib (HR 0·46, 95 % CI 0·23, 0·92; nominal p = 0·03; mPFS not reached in ripretinib arm and 4·9 months in sunitinib arm). Fewer patients experienced grade 3/4 treatment-related treatment-emergent adverse events with ripretinib (17%) versus sunitinib (56%). CONCLUSIONS: Ripretinib demonstrated similar efficacy and a favorable safety profile versus sunitinib as second-line treatment in Chinese GIST patients. Furthermore, ripretinib provided greater clinically meaningful benefit versus sunitinib in patients with KIT exon 11 mutation.
Subject(s)
Antineoplastic Agents , Gastrointestinal Stromal Tumors , Sunitinib , Humans , Antineoplastic Agents/adverse effects , Gastrointestinal Stromal Tumors/drug therapy , Gastrointestinal Stromal Tumors/pathology , Imatinib Mesylate/therapeutic use , Sunitinib/adverse effectsABSTRACT
Soil salinization greatly restricts crop production in arid areas for salinity stress can inhibit crop photosynthesis and growth. Chlorophyll fluorescence and photosynthetic gas exchange (CFPGE) parameters are important indicators of crop photosynthesis and have been widely used to evaluate the impacts of salinity stress on crop photosynthesis and growth. Remote sensing technology can quickly and non-destructively obtain crop information under salinity stress, however, at present, the distribution of spectral features of CFPGE parameters in different regions is still unclear. In this study (2019-2020), under salinity stress conditions, the spectral data of rapeseed leaves were acquired and the CFPGE parameters were simultaneously determined. Then, continuous wavelet transformation (CWT) and standard normal variate (SNV) transformation were utilized to preprocess the raw spectral data. After that, a CFPGE parameter estimation model was constructed by using the partial least squares regression (PLSR) algorithm and the support vector machines (SVM) algorithm based on the spectral features in the red region (600-800 nm) and those in the red, blue-green (350-600 nm), and near-infrared (800-2500 nm) regions. The results showed that the spectral features of CFPGE parameters could be extracted by successive projections algorithm (SPA) based on the CWT preprocessing. The CFPGE parameter estimation model constructed based on the spectral features in the red region (675 nm, 680 nm, 688 nm, 749 nm, and 782 nm) had the highest Fv/Fm estimation accuracy on day 30, with R2c, R2p, and RPD of 0.723, 0.585, and 1.68, respectively. Based on this, the spectral features (578 nm, 976 nm, 1088 nm, 1476 nm, and 2250 nm) in the blue-green and near-infrared regions were added in the variables for modeling, which significantly improved the accuracy and stability of the model, with R2c, R2p, and RPD of 0.886, 0.815, and 2.58, respectively. Therefore, the fusion of the spectral features in the red, blue-green, and near-infrared regions could improve the estimation accuracy of rapeseed leaf CFPGE parameters. This study will provide technical reference for rapid estimation of photosynthetic performance of crops under salinity stress in arid and semi-arid areas.
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To screen environmentally friendly and efficient Cd pollution remediation material, the effects of BC and BF on soil Cd bio-availability and cotton Cd absorption were analyzed under Cd exposure. Besides, the differences in metabolic mechanisms by which biochar (BC) and biofertilizer (BF) affect Cd-contaminated soil and cotton were also analyzed. The results showed that the application of BC and BF increased cotton dry matter accumulation, boll number, and single boll weight, and reduced the Cd content in cotton roots, stems, leaves, and bolls. At harvest, the Cd content in cotton roots in the BC and BF groups reduced by 15.23% and 16.33%, respectively, compared with that in the control. This was attributed to the conversion of carbonate-bound Cd (carbon-Cd) and exchangeable Cd (EX-Cd) by BC and BF into residual Cd (Res-Cd). It should be noted that the soil available Cd (Ava-Cd) content in the BF group was lower than that in the BC group. The metabolomic analysis results showed that for BC vs BF, the relative abundance of differential metabolites Caffeic acid, Xanthurenic acid, and Shikimic acid in soil and cotton roots were up-regulated. Mantel test found that cotton root exudate l-Histinine was correlated with the enrichment of Cd in various organs of cotton. Therefore, the application of BC and BF can alleviate Cd stress by reducing soil Ava-Cd content and cotton's Cd uptake, and BF is superior to BC in reducing Cd content in soil and cotton organs. This study will provide a reference for the development of efficient techniques for the remediation of Cd-polluted alkaline soil, and provide a basis for subsequent metagenomics analysis.
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Cadmium , Gossypium , Environmental Pollution , SoilABSTRACT
Alloy engineering has been utilized as a potent strategy to modulate the oxygen reduction reaction ï¼ORRï¼ activity. However, the regulatory mechanism underpinning the ORR kinetics by means of alloy engineering is still shrouded in ambiguity. This work places emphasis on the kinetics of the ORR concerning Pt3M (M = Cr, Co, Cu, Pd, Sn, and Ir) catalysts, and integrates theoretical prognostication and experimental validation to illuminate the fundamental principles of alloy engineering. The ORR kinetic activity, as prognosticated by theory, shows significant agreement with experimental results, provided that the rate-determining step (RDS) accounts for a dominant role in the potential-independent kinetic mechanism. In essence, alloy engineering manipulates electronic properties through electron transfer to modulate intermediate adsorption and adjusts the interface electric field (Efield) to regulate hydrogen atom transport, ultimately influencing kinetics. The Efield holds greater significance in ORR kinetics compared to the intermediate adsorption (EadsO), the corresponding degrees of correlation with free energy barriers (Ea) of RDS are -0.89, and 0.75, respectively. This work highlights the nature of alloy engineering for ORR kinetics modulation and assists in the design of efficient catalysts.
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In recent years, the improvement of soil cadmium (Cd) contamination remediation effect of biochar by modification has received wide attention. However, the effect of combined modification on biochar performance in soil Cd contamination remediation and the mechanism are still unclear. In this study, cotton straw biochar and maize straw biochar were co-modified by KOH (0, 3, 5 mol L-1), K3PO4, and urea. Then, two modified biochars with high Cd adsorption capacity were selected to test the soil Cd contamination remediation effect through a pot experiment. The results showed that the combined modification by using KOH, K3PO4, and urea significantly increased the specific surface area and nitrogen (N) and phosphorus (P) contents of biochar, providing more adsorption sites for Cd. Among the modified biochar, the cotton straw biochar modified with KOH (3 mol L-1), K3PO4, and urea (m3-CSB) had the highest adsorption capacity (111.25 mg g-1), which was 7.86 times that of cotton straw biochar (CSB). The m3-CSB for adsorption isotherm and kinetics of Cd conformed to the Langmuir model and Pseudo-second-order kinetic equation, respectively. In the pot experiment, under different exogenous Cd levels (0 (Cd0), 4 (Cd4), and 8 (Cd8) mg kg-1), m3-CSB treatment decreased soil available Cd content the most (51.68%-63.4%) compared with other biochar treatments. Besides, m3-CSB treatment significantly promoted the transformation of acid-soluble Cd to reducible, oxidizable, and residual Cd, reducing the bioavailability of Cd. At the Cd4 level, the application of m3-CSB significantly reduced cotton Cd uptake compared to CK, and the maximum reduction of Cd content in cotton fibers was as high as 81.95%. Therefore, cotton straw biochar modified with KOH (3 mol L-1), K3PO4, and urea has great potential in the remediation of soil Cd contamination.
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Soil salinization is one of the main causes of land degradation in arid and semi-arid areas. Timely and accurate monitoring of soil salinity in different areas is a prerequisite for amelioration. Hyperspectral technology has been widely used in soil salinity monitoring due to its high efficiency and rapidity. However, vegetation cover is an inevitable interference in the direct acquisition of soil spectra during crop growth period, which greatly limits the monitoring of soil salinity by remote sensing. Due to high soil salinity could lead to difficulty in plants' water absorption, and inhibit plant dry matter accumulation, a method for monitoring root zone soil salinity by combining vegetation canopy spectral information and crop aboveground growth parameters was proposed in this study. The canopy spectral information was acquired by a spectroradiometer, and then variable importance in projection (VIP), competitive adaptive reweighted sampling (CARS), and random frog algorithm (RFA) were used to extract the salinity spectral features in cotton canopy spectrum. The extracted features were then used to estimate root zone soil salinity in cotton field by combining with cotton plant height, aboveground biomass, and shoot water content. The results showed that there was a negative correlation between plant height/aboveground biomass/shoot water content and soil salinity in 0-20, 0-40, and 0-60 cm soil layers at different growth stages of cotton. Spectral feature selection by the three methods all improved the prediction accuracy of soil salinity, especially CARS. The prediction accuracy based on the combination of spectral features and cotton growth parameters was significantly higher than that based on only spectral features, with R2 increasing by 10.01%, 18.35%, and 29.90% for the 0-20, 0-40, and 0-60 cm soil layer, respectively. The model constructed based on the first derivative spectral preprocessing, spectral feature selection by CARS, cotton plant height, and shoot water content had the highest accuracy for each soil layer, with R2 of 0.715,0.769, and 0.742 for the 0-20, 0-40, 0-60 cm soil layer, respectively. Therefore, the method by combining cotton canopy hyperspectral data and plant growth parameters could significantly improve the prediction accuracy of root zone soil salinity under vegetation cover conditions. This is of great significance for the amelioration of saline soil in salinized farmlands arid areas.
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Purpose: Silent mating type information regulator 2 homolog 1 (SIRT1) and autophagy have a two-way action (promoting cell death or survival) on the progression and treatment of gastric cancer (GC) under different conditions or environments. This study aimed to investigate the effects and underlying mechanism of SIRT1 on autophagy and the malignant biological behavior of GC cells under conditions of glucose deprivation (GD). Materials and methods: Human immortalized gastric mucosal cell GES-1 and GC cell lines SGC-7901, BGC-823, MKN-45 and MKN-28 were utilized. A sugar-free or low-sugar (glucose concentration, 2.5 mmol/L) DMEM medium was used to simulate GD. Additionally, CCK8, colony formation, scratches, transwell, siRNA interference, mRFP-GFP-LC3 adenovirus infection, flow cytometry and western blot assays were performed to investigate the role of SIRT1 in autophagy and malignant biological behaviors (proliferation, migration, invasion, apoptosis and cell cycle) of GC under GD and the underlying mechanism. Results: SGC-7901 cells had the longest tolerance time to GD culture conditions, which had the highest expression of SIRT1 protein and the level of basal autophagy. With the extension of GD time, the autophagy activity in SGC-7901 cells also increased. Under GD conditions, we found a close relationship between SIRT1, FoxO1 and Rab7 in SGC-7901 cells. SIRT1 regulated the activity of FoxO1 and upregulated the expression of Rab7 through deacetylation, which ultimately affected autophagy in GC cells. In addition, changing the expression of FoxO1 provided feedback on the expression of SIRT1 in the cell. Reducing SIRT1, FoxO1 or Rab7 expression significantly inhibited the autophagy levels of GC cells under GD conditions, decreased the tolerance of GC cells to GD, enhanced the inhibition of GD in GC cell proliferation, migration and invasion and increased apoptosis induced by GD. Conclusion: The SIRT1-FoxO1-Rab7 pathway is crucial for the autophagy and malignant biological behaviors of GC cells under GD conditions, which could be a new target for the treatment of GC.
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OBJECTIVE: To examine the effectiveness of decortication to treat chronic tuberculous empyema (TE) using uniport video-assisted thoracoscopic surgery (VATS) versus conventional triport VATS. METHODS: Data from consecutive patients with stage II or III TE who underwent decortication with either uniport VATS (uniportal group) between July and December 2017, or triport VATS between January and July 2018 (triportal group), were retrospectively analysed. VATS procedures were performed under general anaesthesia with double lumen endotracheal intubation and clinical outcomes were compared between the two groups. RESULTS: Clinical data were comparable between the groups (20 patients in each) regarding demographic and baseline characteristics, operative and postoperative characteristics, surgical procedure-related complications, and postoperative adverse events. No surgical procedure-related complications occurred during the perioperative period in either group. Threshold values for mechanical pain at 8 h postoperatively were significantly higher in the triportal group versus the uniportal group. Furthermore, the incidence of nausea and vomiting was significantly lower in the uniportal versus triportal group. In the triportal group, one patient required readmission and further intervention due to recurrence. CONCLUSIONS: Uniport VATS decortication for stages II and III TE may be a feasible and safe procedure in selected patients. Moreover, uniport VATS may be less painful than triport VATS.
Subject(s)
Empyema, Tuberculous , Thoracic Surgery, Video-Assisted , Humans , Thoracic Surgery, Video-Assisted/adverse effects , Thoracic Surgery, Video-Assisted/methods , Empyema, Tuberculous/etiology , Retrospective Studies , Pneumonectomy/methods , Pain/etiologyABSTRACT
Convolutional neural networks (CNNs) have been successfully applied to various fields. However, CNNs' overparameterization requires more memory and training time, making it unsuitable for some resource-constrained devices. To address this issue, filter pruning as one of the most efficient ways was proposed. In this article, we propose a feature-discrimination-based filter importance criterion, uniform response criterion (URC), as a key component of filter pruning. It converts the maximum activation responses into probabilities and then measures the importance of the filter through the distribution of these probabilities over classes. However, applying URC directly to global threshold pruning may cause some problems. The first problem is that some layers will be completely pruned under global pruning settings. The second problem is that global threshold pruning neglects that filters in different layers have different importance. To address these issues, we propose hierarchical threshold pruning (HTP) with URC. It performs a pruning step limited in a relatively redundant layer rather than comparing the filters' importance across all layers, which can avoid some important filters being pruned. The effectiveness of our method benefits from three techniques: 1) measuring filter importance by URC; 2) normalizing filter scores; and 3) conducting prune in relatively redundant layers. Extensive experiments on CIFAR-10/100 and ImageNet show that our method achieves the state-of-the-art performance on multiple benchmarks.
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Manganese-based Na superionic conductors (NASICONs) Na4 MnCr(PO4 )3 with three-electron reaction are attractive cathode materials for sodium-ion batteries. However, the irreversible distortion of Mn local structure leads to sluggish electrode kinetics, voltage hysteresis, and poor cycling stability. Here, SiO4 is introduced to substitute PO4 to modulate the local environment of Mn to activate the redox activity and stabilize the reversibility of Na4 MnCr(PO4 )2.9 (SiO4 )0.1 (NMCP-Si). A combined experimental and theoretical investigation have been undertaken to reveal the evolution of electronic structures and Na storage properties associated with SiO4 substitution. The NMCP-Si exhibits much-enhanced rate capability and cycling stability, being attributed to the unique Jahn-Teller distortion (Mn3+ ) that facilitates sodium de/insertion kinetics by optimizing the Na ion diffusion channels. This work addresses the challenge of stabilizing the structure of Mn-based NASICONs and represents a breakthrough in understanding how to improve the Na+ conductivity by regulating local structure.
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Increased use and implementation of automation, accelerated by the COVID-19 pandemic, gives rise to a new phenomenon: occupation insecurity. In this paper, we conceptualize and define occupation insecurity, as well as develop an Occupation Insecurity Scale (OCIS) to measure it. From focus groups, subject-matter expert interviews, and a quantitative pilot study, two dimensions emerged: global occupation insecurity, which refers to employees' fear that their occupations might disappear, and content occupation insecurity, which addresses employees' concern that (the tasks of) their occupations might significantly change due to automation. In a survey-study sampling 1373 UK employees, psychometric properties of OCIS were examined in terms of reliability, construct validity, measurement invariance (across gender, age, and occupational position), convergent and divergent validity (with job and career insecurity), external discriminant validity (with organizational future time perspective), external validity (by comparing theoretically secure vs. insecure groups), and external and incremental validity (by examining burnout and work engagement as potential outcomes of occupation insecurity). Overall, OCIS shows good results in terms of reliability and validity. Therefore, OCIS offers an avenue to measure and address occupation insecurity before it can impact employee wellbeing and organizational performance.
Subject(s)
COVID-19 , Employment , Humans , Concept Formation , Pandemics , Pilot Projects , Reproducibility of Results , COVID-19/epidemiology , Occupations , AutomationABSTRACT
All tissue development and replenishment relies upon the breaking of symmetries leading to the morphological and operational differentiation of progenitor cells into more specialized cells. One of the main engines driving this process is the Notch signal transduction pathway, a ubiquitous signalling system found in the vast majority of metazoan cell types characterized to date. Broadly speaking, Notch receptor activity is governed by a balance between two processes: 1) intercellular Notch transactivation triggered via interactions between receptors and ligands expressed in neighbouring cells; 2) intracellular cis inhibition caused by ligands binding to receptors within the same cell. Additionally, recent reports have also unveiled evidence of cis activation. Whilst context-dependent Notch receptor clustering has been hypothesized, to date, Notch signalling has been assumed to involve an interplay between receptor and ligand monomers. In this study, we demonstrate biochemically, through a mutational analysis of DLL4, both in vitro and in tissue culture cells, that Notch ligands can efficiently self-associate. We found that the membrane proximal EGF-like repeat of DLL4 was necessary and sufficient to promote oligomerization/dimerization. Mechanistically, our experimental evidence supports the view that DLL4 ligand dimerization is specifically required for cis-inhibition of Notch receptor activity. To further substantiate these findings, we have adapted and extended existing ordinary differential equation-based models of Notch signalling to take account of the ligand dimerization-dependent cis-inhibition reported here. Our new model faithfully recapitulates our experimental data and improves predictions based upon published data. Collectively, our work favours a model in which net output following Notch receptor/ligand binding results from ligand monomer-driven Notch receptor transactivation (and cis activation) counterposed by ligand dimer-mediated cis-inhibition.
Subject(s)
Intercellular Signaling Peptides and Proteins , Receptors, Notch , Animals , Calcium-Binding Proteins/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Intercellular Signaling Peptides and Proteins/metabolism , Ligands , Receptor, Notch1/metabolism , Receptors, Notch/metabolism , Signal Transduction , Protein MultimerizationABSTRACT
Voltage reversal is a severe issue in proton exchange membrane fuel cells (PEMFCs), which can be overcome by adding oxygen evolution electrocatalysts (OER) based on iridium oxide (IrOX) to the anode catalyst layer. However, the crystal structure and antireversal properties of such anode materials have been rarely investigated. Herein, we report amorphous IrOX and explore the transformation of crystal structure under heat treatment to examine their antireversal performance in PEMFCs. It is found that heat treatment results in larger catalyst particles which consequences lower OER activity; however, it shows better voltage reverse tolerance (132.2 min). These investigations demonstrate that a balance is crucial between activity and durability in antireversal properties for PEMFCs. Physical characterizations reveal that improved stability and reversal tolerance is attributed to crystallinity and preferred orientation of IrOX crystals as well as existence of amorphous and crystalline IrOX. This work proposes a attempt to use the mixed phase IrOX in the antireversal anode catalyst and highlights the role of corresponding particle size and durability characteristics for the long-term durability of PEMFCs.
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Background: Natural orifice specimen extraction surgery (NOSES) has been widely applied to the treatment of colorectal cancer. This study aim to investigate the short-term and survival outcomes of transrectal specimen extraction after laparoscopic right hemicolectomy. Methods: From January 2016 to December 2021, a total of 166 consecutive patients with right colon cancer who underwent laparoscopic right hemicolectomy in Cancer Hospital of Chinese Academy of Medical Sciences and Beijing Hospital were identified. Baseline data, perioperative parameters, anal function, inflammatory indicators and survival outcomes were collected and compared. Results: Totally, 24 patients who underwent transrectal NOSE were matched with 24 patients who received conventional laparoscopic surgery (LAP). Patients in NOSES group had a significantly lower incidence of incision infection (0 vs 20.8%, P=0.048), faster recovery of gastrointestinal function (2.1 vs 3,1 days, P=0.032) compared with those in LAP group. In addition, patients in the NOSE group experienced significantly less postoperative pain on POD1 (2.3 vs 4.4, P<0.001), POD3 (2.1 vs 3.9, P<0.001), and POD5 (1.7 vs 2.8, P=0.011). Regarding to anal function 6 months after surgery, no significant difference was observed in Wexner incontinence scale (9.8 vs 9.5, P=0.559) between the two groups. In terms of indicators of the inflammatory response, there were no significant differences in body temperature, neutrophils, and PCT levels between the two groups. However, CRP levels in the NOSES group on POD 3 (6.9 vs 5.1 mg/L, P=0.016) and POD 5 (3.8 vs 2.6 mg/L, P=0.027) were significantly higher than in the LAP group. With regarded to survival outcomes, patients in the NOSES group were similar to those in the LAP group for 3-year OS (100% vs 91.2%, P=0.949), 3-year DFS (86.2% vs 84.8%, P=0.949), and 3-year LRFS (94.2% vs 88.7%, P=0.549). Conclusion: For total laparoscopic right hemicolectomy, transrectal NOSE is effective and safe, and associated with lower incidence of wound infection, less pain, faster recovery, and similar survival outcomes compared to conventional laparoscopic surgery.