Synthesis of Branched Polyethylene via Bulky α-Diimine Nickel(II)-Catalyzed Ethylene Chain-Walking Polymerization

The catalysis of olefin polymerization through the chain-walking process is a subject of great interest. In this contribution, the successful synthesis of a Brookhart-type unsymmetrical α-diimine nickel catalyst Ni, which contains both dibenzhydryl and phenyl groups, was determined by X-ray crystallography. The compound has a pseudo-tetrahedral geometry at the Ni center, showing pseudo-C2-symmetry. Upon activation with modified methylaluminoxane (MMAO), Ni1 exhibits high catalytic activity up to 1.02 × 107 g PE (mol Ni h)−1 toward ethylene polymerization, enabling the synthesis of high molecular weight branched polyethylene. The molecular weights and branching densities could be tuned over a very wide range. The polymerization results indicated the possibility of precise microstructure control, depending on the polymerization temperature. The branching densities were decreased with increasing the polymerization temperature.

Branched fibrous amidoxime adsorbent with ultrafast adsorption rate and high amidoxime utilization for uranium extraction from seawater

Direct collection of uranium from low uranium systems via adsorption remains challenging.Fibrous sorbent materials with amidoxime(AO)groups are promising adsorbents for uranium extraction from seawater.However,low AO adsorption group utilization remains an issue.We herein fabricated a branched structure containing AO groups on polypropylene/polyethylene spun-laced nonwoven(PP/PE SNW)fibers using grafting polymerization induced by radiation(RIGP)to improve AO utilization.The chemical structures,thermal properties,and surface morphologies of the raw and treated PP/PE SNW fibers were studied.The results show that an adsorptive functional layer with a branching structure was successfully anchored to the fiber surface.The adsorption properties were investigated using batch adsorption experiments in simulated seawater with an initial uranium concentration of 500μg·L^(−1)(pH 4,25℃).The maximum adsorption capacity of the adsorbent material was 137.3 mg·g^(−1)within 24 h;moreover,the uranyl removal reached 96%within 240 min.The adsorbent had an AO utilization rate of 1/3.5 and was stable over a pH range of 4–10,with good selectivity and reusability,demonstrating its potential for seawater uranium extraction.

Diagnostic value of methylated branched chain amino acid transaminase 1/IKAROS family zinc finger 1 for colorectal cancer

BACKGROUND The diagnostic value of combined methylated branched chain amino acid transaminase 1(BCAT1)/IKAROS family zinc finger 1(IKZF1)in plasma for colorectal cancer(CRC)has been explored since 2015.Recently,several related studies have published their results and showed its diagnostic efficacy.AIM To analyze the diagnostic value of methylated BCAT1/IKZF1 in plasma for screening and postoperative follow-up of CRC.METHODS The candidate studies were identified by searching the PubMed,Embase,Cochrane Library,CNKI,and Wanfang databases from May 31,2003 to June 1,2023.Sensitivity,specificity,and diagnostic accuracy were calculated by merging ratios or means.RESULTS Twelve eligible studies were included in the analysis,involving 6561 participants.The sensitivity of methylated BCAT1/IKZF1 in plasma for CRC diagnosis was 60%[95%confidence interval(CI)53-67]and specificity was 92%(95%CI:90-94).The positive and negative likelihood ratios were 8.0(95%CI:5.8-11.0)and 0.43(95%CI:0.36-0.52),respectively.Diagnostic odds ratio was 19(95%CI:11-30)and area under the curve was 0.88(95%CI:0.85-0.91).The sensitivity and specificity for CRC screening were 64%(95%CI:59-69)and 92%(95%CI:91-93),respectively.The sensitivity and specificity for recurrence detection during follow-up were 54%CONCLUSION The detection of methylated BCAT1/IKZF1 in plasma,as a non-invasive detection method of circulating tumor DNA,has potential CRC diagnosis,but the clinical application prospect needs to be further explored.

Left bundle branch pacing vs biventricular pacing in heart failure patients with left bundle branch block:A systematic review and meta-analysis

BACKGROUND Left bundle branch pacing(LBBP)is a novel pacing modality of cardiac resynchronization therapy(CRT)that achieves more physiologic native ventricular activation than biventricular pacing(BiVP).AIM To explore the validity of electromechanical resynchronization,clinical and echocardiographic response of LBBP-CRT.METHODS Systematic review and Meta-analysis were conducted in accordance with the standard guidelines as mentioned in detail in the methodology section.RESULTS In our analysis,the success rate of LBBP-CRT was determined to be 91.1%.LBBP CRT significantly shortened QRS duration,with significant improvement in echocardiographic parameters,including left ventricular ejection fraction,left ventricular end-diastolic diameter and left ventricular end-systolic diameter in comparison with BiVP-CRT.CONCLUSION A significant reduction in New York Heart Association class and B-type natriuretic peptide levels was also observed in the LBBP-CRT group vs BiVP-CRT group.Lastly,the LBBP-CRT cohort had a reduced pacing threshold at follow-up as compared to BiVP-CRT.

Enhanced adsorption of target branched compounds including antibiotic norfloxacin frameworks on mild steel surface for efficient protection: An experimental and molecular modelling study

In this study, an approach was proposed to employ new target branched compounds(TBCs) including multiple antibiotic norfloxacin frameworks for intensified adsorption films to achieve super protection of mild steel in HCl medium. Thus, the TBCs containing bis/tri norfloxacin skeletons were synthesized by multi-step preparation route. In addition, the reference linear compound(RLC) including a single norfloxacin part was also synthesized. The chemical structures of these compounds were confirmed by various means. It was demonstrated that the TBCs could form the tough adsorption films on the surface of mild steel, which could be processed mainly through chemisorption effect. The electrochemical analysis suggested that the TBCs displayed superior corrosion inhibition performance for low carbon steel in1.0 mol·L^(-1) HCl solution over the RLC(RLC, 87.80%;TBC1, 97.63%;TBC2, 98.35%), which was further understood by the molecular modelling. The isotherm adsorption plots were employed to analyze the spontaneous adsorption process of the TBCs on low carbon steel surface, and a prominent chemisorption could be inferred by the standard Gibbs free energy changes of the adsorption.

Anomalous diffusion in branched elliptical structure

Diffusion in narrow curved channels with dead-ends as in extracellular space in the biological tissues,e.g.,brain,tumors,muscles,etc.is a geometrically induced complex diffusion and is relevant to different kinds of biological,physical,and chemical systems.In this paper,we study the effects of geometry and confinement on the diffusion process in an elliptical comb-like structure and analyze its statistical properties.The ellipse domain whose boundary has the polar equationρ(θ)=b/√1−e^(2)cos^(2)θ with 0<e<1,θ∈[0,2π],and b as a constant,can be obtained through stretched radius r such that Υ=rρ(θ)with r∈[0,1].We suppose that,for fixed radius r=R,an elliptical motion takes place and is interspersed with a radial motion inward and outward of the ellipse.The probability distribution function(PDF)in the structure and the marginal PDF and mean square displacement(MSD)along the backbone are obtained numerically.The results show that a transient sub-diffusion behavior dominates the process for a time followed by a saturating state.The sub-diffusion regime and saturation threshold are affected by the length of the elliptical channel lateral branch and its curvature.

Left bundle branch pacing set to outshine biventricular pacing for cardiac resynchronization therapy?

The deleterious effects of long-term right ventricular pacing necessitated the search for alternative pacing sites which could prevent or alleviate pacinginduced cardiomyopathy.Until recently,biventricular pacing(BiVP)was the only modality which could mitigate or prevent pacing induced dysfunction.Further,BiVP could resynchronize the baseline electromechanical dssynchrony in heart failure and improve outcomes.However,the high non-response rate of around 20%-30%remains a major limitation.This non-response has been largely attributable to the direct non-physiological stimulation of the left ventricular myocardium bypassing the conduction system.To overcome this limitation,the concept of conduction system pacing(CSP)came up.Despite initial success of the first CSP via His bundle pacing(HBP),certain drawbacks including lead instability and dislodgements,steep learning curve and rapid battery depletion on many occasions prevented its widespread use for cardiac resynchronization therapy(CRT).Subsequently,CSP via left bundle branch-area pacing(LBBP)was developed in 2018,which over the last few years has shown efficacy comparable to BiVP-CRT in small observational studies.Further,its safety has also been well established and is largely free of the pitfalls of the HBP-CRT.In the recent metanalysis by Yasmin et al,comprising of 6 studies with 389 participants,LBBPCRT was superior to BiVP-CRT in terms of QRS duration,left ventricular ejection fraction,cardiac chamber dimensions,lead thresholds,and functional status amongst heart failure patients with left bundle branch block.However,there are important limitations of the study including the small overall numbers,inclusion of only a single small randomized controlled trial(RCT)and a small follow-up duration.Further,the entire study population analyzed was from China which makes generalizability a concern.Despite the concerns,the meta-analysis adds to the growing body of evidence demonstrating the efficacy of LBBP-CRT.At this stage,one must acknowledge that the fact that still our opinions on this technique are largely based on observational data and there is a dire need for larger RCTs to ascertain the position of LBBPCRT in management of heart failure patients with left bundle branch block.

In-Situ Growing of Branched CNFs on Reusable RCFs to Construct Hierarchical Cross-Linked Composite for Enhanced Microwave Absorption

The recycling of carbon fibers and protection from unwanted microwave radiation are two important environmental issues that need to be addressed in modern society.Herein,branched carbon nanofibers(CNFs)were grown in-situ on recycled carbon fibers(RCFs)through the chemical vapor deposition method using nickel as catalysts and thiophene as aided-catalysts.The effect of thiophene on the growth morphology of CNFs was investigated.Correspondingly,branched CNFs-RCFs and straight CNFs-RCFs were respectively obtained in the presence and absence of thiophene.The microstructure and electromagnetic behaviour investigations have shown that the branched CNFs possess a typical multi-branched structure,with more defects,pores and a larger specific surface area than the straight CNFs,which lead to better impedance matching and adequate dielectric loss ability for the branched CNFs-RCFs.The reflection loss(RL)results show that the branched CNFs-RCFs exhibit an optimum RL of -23.6 dB at 1.5 mm and a best effective absorption bandwidth(EAB)of 7.5 GHz at 2.0 mm.This research provides an innovative microwave absorbing material with adequate absorbing strength and outstanding EAB,while also promoting the sustainable reuse of the RCFs resources.

Proppant transport law in multi-branched fractures induced by volume fracturing

To further clarify the proppant transport and placement law in multi-branched fractures induced by volume fracturing, proppant transport simulation experiments were performed with different fracture shapes, sand ratios, branched fracture opening time and injection sequence of proppants in varied particle sizes. The results show that the settled proppant height increases and the placement length decreases in main fractures as the fracturing fluid diverts gradually to the branched fractures at different positions. The flow rate in branched fractures is the main factor affecting their filling. The diverion to branched fractures leads to low flow rate and poor filling of far-wellbore branched fractures. The inclined fracture wall exerts a frictional force on the proppant to slow its settlement, thus enhancing the vertical proppant distribution in the fracture. The increase of sand ratio can improve the filling of near-wellbore main fracture and far-wellbore branched fracture and also increase the settled proppant height in main fracture. Due to the limitation of fracture height, when the sand ratio increases to a certain level, the increment of fracture filling decreases. When branched fracture is always open(or extends continuously), the supporting effect on the branched fractures is the best, but the proppant placement length within the main fractures is shorter. The fractures support effect is better when it is first closed and then opened(or extends in late stage) than when it is first opened and then closed(or extends in early stage). Injecting proppants with different particle sizes in a specific sequence can improve the placement lengths of main fracture and branched fracture. Injection of proppants in an ascending order of particle size improves the near-wellbore fracture filling, to a better extent than that in a descending order of particle size.

Engineering high amylose and resistant starch in maize by CRISPR/Cas9-mediated editing of starch branching enzymes

To improve the amylose content(AC)and resistant starch content(RSC)of maize kernel starch,we employed the CRISPR/Cas9 system to create mutants of starch branching enzyme I(SBEI)and starch branching enzyme IIb(SBEIIb).A frameshift mutation in SBEI(E1,a nucleotide insertion in exon 6)led to plants with higher RSC(1.07%),lower hundred-kernel weight(HKW,24.71±0.14 g),and lower plant height(PH,218.50±9.42 cm)compared to the wild type(WT).Like the WT,E1 kernel starch had irregular,polygonal shapes with sharp edges.A frameshift mutation in SBEIIb(E2,a four-nucleotide deletion in exon 8)led to higher AC(53.48%)and higher RSC(26.93%)than that for the WT.E2 kernel starch was significantly different from the WT regarding granule morphology,chain length distribution pattern,X-ray diffraction pattern,and thermal characteristics;the starch granules were more irregular in shape and comprised typical B-type crystals.Mutating SBEI and SBEIIb(E12)had a synergistic effect on RSC,HKW,PH,starch properties,and starch biosynthesis-associated gene expression.SBEIIa,SS1,SSIIa,SSIIIa,and SSIIIb were upregulated in E12 endosperm compared to WT endosperm.This study lays the foundation for rapidly improving the starch properties of elite maize lines.

Long-Term Impacts of Tree Architectures and Branch Configurations on Tree Growth, Yield, Fruit Quality Attributes, and Leaf Minerals in “Aztec Fuji” Apple

Canopy and branch architectures in high-density orchards can be crucial in production and fruit quality. The influence of two canopy orientations (Upright and Tilted) in combination with two arm (branch) architectures (Shortened or Overlapped) on tree growth, yield components, fruit quality, and leaf mineral nutrients in an “Aztec Fuji” apple (Malus domestica Bork.) high-density orchard was studied over five years. Tilted trees with shortened arm configuration (TilShArm) always had significantly larger trunk cross-sectional area (TCSA) than Upright trees with an Overlapped arm configuration (UpOverArm) every year from 2012 to 2016. Trees with a TilShArm system had more cumulative fruit per tree than those with an Upright orientation. Trees with a tilted canopy (TilShArm and TilOverArm) tended to have higher yield per tree and yield per hectare than those with an upright system. Trees with a TilShArm system were more precocious and had more yield per tree than those with an upright canopy orientation in 2012. When values were polled over five years, trees with an upright canopy-shortened arm system (UpShArm) treatment had a lower biennial bearing index (BBI) than those with an upright canopy-overlapped system (UpOverArm). Trees receiving an arm shortening (UpShArm or TilShArm) configuration often had larger fruits than those with overlapped arms (UpOverArm and TilOverArm). Fruit from trees receiving an UpOverArm had higher fruit firmness than those from trees with other canopy-branch arrangements at harvest due to their smaller size. Fruit from trees with a TilShArm and TilOverArm had significantly higher water core and bitter pit but lower sunburn than trees with an upright canopy (UpShArm and UpOverArm). Leaves from trees with an UpOverArm canopy-branch configuration had the lowest leaf Ca but the highest leaf K and Fe concentrations among all treatments.

The Channel Branches & Network Vessels on the Tianhui Lacquered Meridian Figurine——Taking the Heart-Regulated Channel as an Example

Along with the surge of unearthed medical literature and cultural relics in recent years,a network of channels in the system of medical conduit vessels(meridians) during the early Western Han dynasty has become much clearer gradually.In it,the increasing number of channel branches,network vessels and needle insertion holes(acupoints) is an important feature of the development of channel medicine during the Western Han dynasty.This is not only a reflection of the expanding requirements of the theoretical system of the main trunk channels and other vessels,but also an inevitable result of the continuous enrichment and accumulation of clinical experience.This article integrates the information about channel branches,network vessels,inscriptions,dots and further relics on the Tianhui(天回) Lacquered Meridian Figurine to compare the unearthed literature of the channel genre with the transmitted classical literature about acupuncture.The “Heart-Regulated Channel” in Medical Manuscripts on Bamboo Slips from Tianhui(《天回医简》) serves as an example to explain the occurrence,development and changes of the channel branches and network vessels in the early system of medical channels.

Predicting cardiovascular events in out-of-hospital patients presenting with atypical chest pain and complete left bundle branch block: role of CTA and echocardiographic Global Longitudinal Strain

Background Out-of-hospital patients presenting with atypical chest pain and complete left bundle branch block(LBBB)have to be stratified for the presence of coronary artery disease and the risk of developing heart failure(HF).We investigated the pro-gnostic role of coronary CT-angiography(CTA)and echocardiographic global longitudinal strain(GLS)in those patients in a mid-term follow-up.Methods Out-of-hospital patients with LBBB underwent echocardiography and a 64-slice CT angiography were evaluated ret-rospectively.Development of HF or a cardiovascular death were the events scheduled.Results Seventy-eight patients(32 female;mean age:66.0±10.4 years were enrolled.During a follow-up of 33 months(IQR:17-77),one patient(1.5%)experienced a cardiovascular death,14 patients(17.9%)required urgent outpatient visits due to acute de-compensated HF(12 hospitalizations).Echocardiography showed a slightly reduced left ventricular ejection fraction(LVEF)(50.0%±9.8%)and GLS within the normal range(-16.2%±4.1%).CTA analysis showed coronary stenosis>50%in 28 patients(35.9%).A high Agatston score(>100)was observed in 29.5%.Notably,25 patients(32.1%)were diagnosed with left main coron-ary artery disease and 15 patients(16.7%)underwent revascularization during the follow up.Significant associations were ob-served between events and LVEF(P=0.001),diastolic dysfunction grade≥2(P=0.02),GLS(P<0.001),multiple coronary stenos-is(P=0.04)and Agatston score(P=0.05).Multivariate analysis confirmed the relationships with LVEF(R^(2)=0.89,P<0.001),dia-stolic dysfunction(R^(2)=3.30,P=0.04),GLS(R^(2)=1.43,P<0.001),and Agatston score(R^(2)=1.01,P=0.05).Conclusions In patients with complete LBBB,CTA and GLS identified those at a high risk of development HF.

Left bundle branch area pacing combined with implantable cardioverter-defibrillator treatment for heart failure after myocardial infarction

Left bundle branch area pacing(LBBAP)has emerged as a new physiological pacing mode.Previous studies have confirmed the feasibility and efficacy of LBBAP for cardiac resynchronization therapy(CRT)in heart failure(HF)patients with left bundle branch block(LBBB)and a narrower QRS duration(QRSd)to have a higher percentage of super responders,and lower pacing thresholds than biventricular pacing(BiVP).

Unilateral branch retinal artery occlusion in association with COVID-19:a case report

Dear Editor,I am Kunihiko Hirosawa of the Department of Ophthalmology at Juntendo University Hospital.I am writing to present a case of concomitant Coronavirus Disease 2019(COVID-19)with branch retinal artery occlusion(BRAO).BRAO presents as a sudden,painless loss of vision on the afflicted side and is most often focal in nature[1].

ON THE EMPTY BALLS OF A CRITICAL OR SUBCRITICAL BRANCHING RANDOM WALK

Let{Z_(n)}_(n)≥0 be a critical or subcritical d-dimensional branching random walk started from a Poisson random measure whose intensity measure is the Lebesugue measure on R^(d).Denote by R_(n):=sup{u>0:Z_(n)({x∈R^(d):∣x∣<u})=0}the radius of the largest empty ball centered at the origin of Z_(n).In this work,we prove that after suitable renormalization,Rn converges in law to some non-degenerate distribution as n→∞.Furthermore,our work shows that the renormalization scales depend on the offspring law and the dimension of the branching random walk.This completes the results of Révész[13]for the critical binary branching Wiener process.

Thermal pretreatment of willow branches impacts yield and pore development of activated carbon in subsequent activation with ZnCl_(2) via modifying cellulose structure

Development of pore structures of activated carbon(AC)from activation of biomass with ZnCl_(2) relies on content and structure of cellulose/hemicellulose in the feedstock.Thermal pretreatment of biomass could induce dehydration and/or aromatization to change the structure of cellulose/hemicellulose.This might interfere with evolution of structures of AC,which was investigated herein via thermal pretreatment of willow branch(WB)from 200 to 360℃and the subsequent activation with ZnCl_(2) at 550℃.The results showed that thermal pretreatment at 360℃(WB-360)could lead to substantial pyrolysis to form biochar,with a yield of 31.9%,accompanying with nearly complete destruction of cellulose crystals and remarkably enhanced aromatic degree.However,cellulose residual in WB-360 could still be activated to form AC-360 with specific surface area of 1837.9 m~2·g^(-1),which was lower than that in AC from activation of untreated WB(AC-blank,2077.8 m~2·g^(-1)).Nonetheless,the AC-200 from activation of WB-200 had more developed pores(2113.9 m~2·g^(-1))and superior capability for adsorption of phenol,due to increased permeability of ZnCl_(2) to the largely intact cellulose structure in WB-200.The thermal pretreatment did increase diameters of micropores of AC but reduced the overall yield of AC(26.8%for AC-blank versus 18.0%for AC-360),resulting from accelerated cracking but reduced intensity of condensation.In-situ infrared characterization of the activation showed that ZnCl_(2) mainly catalyzed dehydration,dehydrogenation,condensation,and aromatization but not cracking,suppressing the formation of derivatives of cellulose and lignin in bio-oil.The thermal pretreatment formed phenolic-OH and C=O with higher chemical innerness,which changed the reaction network in activation,shifting morphology of fibrous structures in AC-blank to“melting surface”in AC-200 or AC-280.

DCFNet:An Effective Dual-Branch Cross-Attention Fusion Network for Medical Image Segmentation

Automatic segmentation of medical images provides a reliable scientific basis for disease diagnosis and analysis.Notably,most existing methods that combine the strengths of convolutional neural networks(CNNs)and Transformers have made significant progress.However,there are some limitations in the current integration of CNN and Transformer technology in two key aspects.Firstly,most methods either overlook or fail to fully incorporate the complementary nature between local and global features.Secondly,the significance of integrating the multiscale encoder features from the dual-branch network to enhance the decoding features is often disregarded in methods that combine CNN and Transformer.To address this issue,we present a groundbreaking dual-branch cross-attention fusion network(DCFNet),which efficiently combines the power of Swin Transformer and CNN to generate complementary global and local features.We then designed the Feature Cross-Fusion(FCF)module to efficiently fuse local and global features.In the FCF,the utilization of the Channel-wise Cross-fusion Transformer(CCT)serves the purpose of aggregatingmulti-scale features,and the Feature FusionModule(FFM)is employed to effectively aggregate dual-branch prominent feature regions from the spatial perspective.Furthermore,within the decoding phase of the dual-branch network,our proposed Channel Attention Block(CAB)aims to emphasize the significance of the channel features between the up-sampled features and the features generated by the FCFmodule to enhance the details of the decoding.Experimental results demonstrate that DCFNet exhibits enhanced accuracy in segmentation performance.Compared to other state-of-the-art(SOTA)methods,our segmentation framework exhibits a superior level of competitiveness.DCFNet’s accurate segmentation of medical images can greatly assist medical professionals in making crucial diagnoses of lesion areas in advance.

A Light and Simplified Branch Bending Method for Young Pear Trees

Aiming at high cost and low efficiency of conventional branch bending method in the modern intensive planting and labor-saving cultivation mode of young pear trees,this paper provides a new branch bending method with wide source of raw materials,cheap price and simple operation,which is also suitable for the management of low-age branches in the process of high grafting and upgrading of traditional big trees.

Left bundle branch area pacing:A new era of cardiac resynchronization therapy?

The recent systematic review and meta-analysis provided a comprehensive focus on the current state of cardiac resynchronization therapy(CRT).The authors determined the feasibility of physiological left bundle branch area pacing(LBBAP)in patients indicated for CRT through a careful analysis of trials.They found that LBBAP was associated with significant reductions in QRS duration,New York Heart Association functional class,B-type natriuretic peptide levels,and pacing thresholds as well as improvements in echocardiographic parameters compared to biventricular pacing.