Polypore funga and species diversity in tropical forest ecosystems of Africa,America and Asia,and a comparison with temperate and boreal regions of the Northern Hemisphere

Polypores play a cru cial role in energy recycling and forest regeneration in forest ecosystems.The majority of them are wood degraders;some are forest pathogens and others are ectomycorrhizal symbionts.The basidiocarps provide food and shelter for many organisms,mostly invertebrates,but also some vertebrates,as well as food and medicine for humans.Despite extensive research on the species diversity and phylogenetic relationships of polypores in recent years,there remains a lack of comprehensive understanding of their distribution patterns and species composition at the large scale.Checklists of polypores from the tropical zone,including tropical Africa,tropical America,and tropical Asia,were analyzed for species diversity,distribution patterns,major taxa,and nutritional modes.A total of 1,902 polypore species was found in the three regions,representing 8 orders,46families,and 250 genera of Agaricomycetes.The orders Polyporales(especially the family Polyporaceae)and Hymenochaetales(especially the family Hymenochaetaceae)had the most prolific taxa,with their species accounting for 93.4%of the total polypores listed.Each of 1,565(or 82.3%)of the total 1,902 species were found in only one of the three regions studied,and we treat them temporarily as"regional endemic species".Only 141species were shared among all three regions,accounting for a mere 7.4%.Tropical Africa and tropical America had the greatest number of shared species and the highest S?rensen similarity index(SC)value.Tropical forests had a higher species richness compared with temperate to boreal forests of the Northern Hemisphere,and in addition,also a higher proportion of white rot polypores compared to brown rot and ectomycorrhizal species.This study outlines the distribution patterns and species diversity of polypores in the world,shedding light on their ecological significance in diverse ecosystems.

Mechanistic insights into the active intermediates of 2,6-diaminopyridine dinitration

Mechanistic understanding of the active intermediates of 2,6-diaminopyridine(DAP) dinitration in the concentrated nitric-sulfuric acid system is of crucial importance for the selectivity control of target product, i.e., 2,6-diamino-3,5-dinitropyridine(DADNP). The active intermediates determining the product selectivity are theoretically studied. The HSO_(4)^(-)-NO_(2)^(+) complex is proposed as the dominant active nitrating intermediate for the first time, which shows low energy barrier(i.e., 10.19 kcal·mol^(-1),1 kcal = 4.186 k J) for direct dinitration of DAP to DADNP. The formed water during the reaction results in not only the formation of less active SO_(4)^(2-)-NO_(2)^(+) complex, but also the occurance of DAP sulfonation(DAP-SO_(3)H intermediate)to facilitate the formation of mononitration byproduct. Meanwhile, the accompanied thermal effects cause the generation of undesirable pyridine-NHNO_(2) intermediate, which is difficult to be rearranged to yield DADNP, inhibiting the reaction and thus giving low DAP conversion. The insights reported here elucidates the importance of thermal effects elimination and water content control, confirmed experimentally in the batch-and micro-reaction systems.

One stone three birds:Ni-catalyzed asymmetric allenylic substitution of allenic ethers,hydroalkylation of 1,3-enynes and double alkylation of enynyl ethers

The development of low-cost,earth-abundant and environmentally benign transition metal catalysts,which can catalyze multiple different types of asymmetric reactions,is an important objective in mod-ern asymmetric catalysis.Herein we demonstrate that a chiral Ni/P-Phos catalyst achieves three types of asymmetric reactions:allenylic substitution of racemic allenic ethers,1,4-hydroalkylation of prochiral 1,3-enynes and double alkylation of newly designed enynyl ether reagents.Three methods complement each other and produce various axially chiral allene derivatives bearing a pyrazolidine-3,5-dione unit,which is widely present in drugs and biologically active molecules with versatile pharmacological activities.

Poisoning effect of polyvinyl chloride on the catalytic pyrolysis of mixed plastics over zeolites

Nowadays,the chemical recycling is applied for only 1%of total waste plastics,largely due to contaminants in plastic waste and difficulty in product control.As the major contaminant,polyvinyl chloride(PVC)often forms corrosive hydrogen chloride(HCl)during the chemical recycling,which may cause severe catalyst deactivation and equipment damage.However,the investigation on catalytic pyrolysis(the major route for plastics chemical recycling)of the PVC containing mixed plastics has been rarely reported.Here,catalytic co-pyrolysis of PVC and polyethylene(PE)was studied over an aromatization catalyst,Pt/ZSM-5,since the basic building block aromatics are desired products from plastics chemical recycling.The poisoning effect of PVC vapor on the catalyst stability was explored by collective efforts of thorough product analysis and catalyst characterization.It was found that the HCl evolving from PVC has an autocatalytic effect that promotes the scission of dehydrochlorinated PVC,resulting in the high yield of benzene and acetylene from PVC.On the other hand,the presence of PVC suppressed the aromatics formation from PE,largely due to the poisoning effect of PVC-derived HCl on the Pt/ZSM-5.The deactivation is irreversible as evidenced by the decreased zeolite crystallinity and the loss of strong acid sites that are key to the aromatization,possibly due to the removal of framework Al upon the interaction with HCl.The modification with octadecylphosphonic acid only slightly alleviated the PVC poisoning effect.The insights on the PVC poisoning of zeolite catalysts provided in this work may guide the process design of chemical recycling of PVC containing waste plastics.

Lamellar quasi-solid electrolyte with nanoconfined deep eutectic solvent for high-performance lithium battery

Electrolytes with high-efficiency lithium-ion transfer and reliable safety are of great importance for lithium battery.Although having superior ionic conductivity(10^(−3)–10^(−2) S·cm^(−1)),traditional liquid-state electrolytes always suffer from low lithium-ion transference number(tLi+<0.4)and thus undesirable battery performances.Herein,the deep eutectic solvent(DES)is vacuum-filtered into the~1 nm interlayer channel of vermiculite(Vr)lamellar framework to fabricate a quasi-solid electrolyte(Vr-DES QSE).We demonstrate that the nanoconfinement effect of interlayer channel could facilitate the opening of solvation shell around lithiumion.Meanwhile,the interaction from channel wall could inhibit the movement of anion.These enable high-efficiency lithium-ion transfer:2.61×10^(−4)S·cm^(−1)at 25℃.Importantly,the tLi+value reaches 0.63,which is 4.5 times of that of bulk DES,and much higher than most present liquid/quasi-solid electrolytes.In addition,Vr-DES QSE shows significantly improved interfacial stability with Li anode as compared with DES.The assembled Li symmetric cell can operate stably for 1000 h at 0.1 mA·cm^(−2).The lithium iron phosphate(LFP)|Vr-DES QSE|Li cell exhibits high capacity of 142.1 mAh·g^(−1)after 200 cycles at 25℃ and 0.5 C,with a capacity retention of 94.5%.The strategy of open solvation shell through nanoconfinement effect of lamellar framework may shed light on the development of advanced electrolytes.

Efficient continuous synthesis of 2-hydroxycarbazole and 4-hydroxycarbazole in a millimeter scale photoreactor

2-Hydroxycarbazole and 4-hydroxycarbazole are important chemicals with extensive applications in optoelectronic materials and pharmaceutical field.State of the art yield of 2-hydroxycarbazole is~30%and the reaction time is typically in hours or days.Herein,we developed a green route for the continuous and high-throughput synthesis of 2-hydroxycarbazole and 4-hydroxycarbazole via photochemical intramolecular cyclization of 3–hydroxy-2–chloro-diphenylamine using a self-designed millimeter scale photoreactor,which was designed based on sizing-up and numbering-up strategies for a decent liquid holdup(6.8 m L)and fabricated via femtosecond laser engraving technique.The photochemical synthesis was carried out continuously under the illumination of 365 nm UV-LED with dimethyl sulfoxide as solvent and potassium t-butoxide as catalyst.It was found that under optimized conditions a 2-hydroxycarbazole yield of 31.6%and a 4-hydroxycarbazole yield of 11.1%were obtained with a residence time of 1 min.Compared to semibatch operations,the reaction time was shortened by 1–2 orders of magnitude.As a result,a throughput of 11.3 g/day 2-hydroxycarbazole and 4.0 g/day 4-hydroxycarbazole can be achieved from the photoreactor.It was proposed that the short reaction time and high product yield are resulted from higher photon transfer rates and more uniform photon distribution provided by the millimeter scale photoreactor,which enhances the reaction rates and mitigates overreaction.

Comparative effectiveness of different hepatocellular carcinoma screening intervals or modalities:a systematic review and meta-analysis

Background:Current guidelines recommend hepatocellular carcinoma(HCC)screening in high-risk populations.However,the ideal HCC screening interval and screening modality have not been determined.This study aimed to compare the screening efficacy among different modalities with various intervals.Methods:PubMed and other nine databases were searched through June 30,2021.Binary outcomes were pooled using risk ratio(RR)with 95%confidence intervals(CIs).Survival rates were also pooled using RR with 95%CIs because most eligible studies only provided the number of survival patients instead of hazard ratio.Results:In all,13 studies were included.Two random controlled trials(RCTs)and six cohort studies compared screening intervals for ultrasonography(US)screening and found no significant differences between shorter(3-or 4-month)and longer(6-or 12-month)screening intervals in terms of early HCC proportion,HCC significant mortality,1-year survival rate;screening at 6-month interval significantly increased the proportion of early HCC(RR=1.17,95%confidence interval[CI]:1.08-1.26)and prolonged the 5-year survival rate(RR=1.39,95%CI:1.07-1.82)relative to the 12-month interval results.Three other RCTs and two cohort studies compared different screening modalities in cirrhosis or chronic hepatitis B,which indicated no statistical differences in the proportion of early HCC(RR=0.89,95%CI:0.40-1.96)and HCC mortality(RR=0.69,95%CI:0.23-2.09)between the biannual US and annual computed tomography(CT screening).Biannual US screening showed a lower proportion of early HCC than biannual magnetic resonance imaging(MRI)(RR=0.60,95%CI:0.37-0.97)and biannual US combined with annual CT(RR=1.31,95%CI:1.13-1.51)screening.The proportion of early HCC in the contrast-enhanced US group was slightly higher than that in the B-mode US(RR=1.08,95%CI:1.00-1.23)group.Conclusions:The evidence suggests that 6 months may be the best HCC screening interval for US screening.The effectiveness of CT and MRI is better than US during same screening intervals.However,MRI and CT are more expensive than US,and CT also can increase the risk of radiation exposure.The selection of CT or MRI instead of US should be carefully considered.Registration:No.CRD42020148258 at PROSPERO website(https://www.crd.york.ac.uk/PROSPERO/).

Residence time distribution and heat/mass transfer performance of a millimeter scale butterfly-shaped reactor

A millimeter scale butterfly-shaped reactor was proposed based on sizing-up strategy and fabricated via femtosecond laser engraving. An improvement of mixing performance and residence time distribution was realized by means of contraction and expansion of the reaction channel. The liquid holdup was greatly increased through connection of multiple mixing units. Structure optimization of the reactor was carried out by computational fluid dynamics simulation, from which the effect of reactor internals on mixing and the influence of parallel branching structure on heat transfer were discussed. The UV–vis absorption spectroscopy was used to determine the residence time distribution in the reactor, and characteristic parameters such as skewness and dimensionless variance were obtained. Further, a chained stagnant flow model was proposed to precisely describe the trailing phenomenon caused by fluid stagnation and laminar flow in small scale reactors, which enables a better fit for the experimental results of the asymmetric residence time distribution. In addition, the heat transfer performance of the reactor was investigated, and the overall heat transfer coefficient was 110–600 W m^(-2)K-1in the flow rate range of 10–40 m L/min.

Swelling-induced morpholine functionalized adamantane-containing poly(aryl ether ketone)membranes for vanadium flow batteries

Swelling-induced morpholine functionalized adamantane-containing poly(aryl ether ketone) (MAPEK) membranes were prepared for vanadium flow batteries. MAPEK membranes were prepared from chloromethylated polymer and morpholine and further swelling-induced with hot phosphoric acid to obtain membranes with enhanced ionic conductivity. The swelling, selectivity, and ionic conductivity of MAPEK membranes were regulated by varying the swelling temperature. Selective swelling-induced microphase separation in MAPEK membranes, forming wider ion transport pathways and resulting in low area resistance. The unique rigid adamantane-containing backbone limited the swelling of membranes. Consequently, MAPEK membranes showed excellent selectivity and conductivity (vanadium ion permeability coefficient of MAPEK membranes was lower than 3.82 × 0−7 cm2min−1) (Nafion212 membrane, 42.5 × 0−7 cm2min−1), and MAPEK-150 membrane exhibited low area resistance (0.17 Ωcm2). The vanadium flow batteries (VFB) with MAPEK-150 membrane exhibited high energy efficiency (91.1% at 80 mAcm−2, 81.4% at 200 mAcm−2). Furthermore, MAPEK membranes showed good stability in VFB and oxidative electrolytes. The swelling-induced method utilized in this work is a versatile and facile method to enhance the conductivity of ion-exchange membranes.

Benefits and harms of screening for hepatocellular carcinoma in high-risk populations: systematic review and meta-analysis

Objective:The incidence and mortality of hepatocellular carcinoma(HCC)have been increasing around the world.Current guidelines recommend HCC screening in high-risk population.However,the strength of evidence of ben-efits and harms of HCC screening to support the recommendation was unclear.The objective is to systematically synthesize current evidence on the benefits and harms of HCC screening.Methods:We searched PubMed and nine other databases until August 20,2021.We included cohort studies and RCTs that compared the benefits and harms of screening and non-screening in high-risk population of HCC.Case series studies that reported harms of HCC screening were also included.Pooled risk ratio(RR),according to HCC screening status,was calculated for each benefit outcome(e.g.,HCC mortality,survival rate,proportion of early HCC),using head-to-head meta-analysis.The harmful outcomes(e.g.,proportion of physiological harms provided by non-comparative studies were pooled by prevalence of meta-analysis).Analysis on publication bias and quality of life,subgroup analysis,and sensitivity analysis were also conducted.Results:We included 70 studies,including four random clinical trials(RCTs),63 cohort studies,three case se-ries studies.The meta-analysis of RCTs showed HCC screening was significantly associated with reduced HCC mortality(RR[risk ratio],0.73[95%CI,0.56-0.96];I^(2)=75.1%),prolonged overall survival rates(1-year,RR,1.72[95%CI,1.13-2.61];I^(2)=72.5%;3-year,RR,2.86[95%CI,1.78-4.58];I^(2)=10.1%;and 5-year,RR,2.76[95%CI,1.37-5.54];I^(2)=28.3%),increased proportion of early HCC detection(RR,2.68[95%CI,1.77-4.06];I^(2)=50.4%).Similarly,meta-analysis of cohort studies indicated HCC screening was more effective than non-screening.However,pooled proportion of physiological harms was 16.30%(95%CI:8.92%-23.67%)and most harms were of a mild to moderate severity.Conclusion:The existing evidence suggests HCC screening is more effective than non-screening in high-risk pop-ulation.However,harms of screening should not be ignored.

Antioxidant and immunomodulatory activities of a polysaccharide from Flammulina velutipes

OBJECTIVE: To evaluate the antioxidant and immunomodulatory activities of a unique polysaccharide from the medicinal fungus Flammulina velutipes in vitro.METHODS: Using water extraction and alcohol precipitation, crude polysaccharides were obtained. After purification by DEAE-cellulose 52 ion exchange chromatography and Sephacryl S-300 HR gel filtration chromatography, High performance liquid chromatography equipped with evaporative light-scattering detector, Infrared radiation and Nuclear magnetic resonance were used to evaluate the structure of the polysaccharide. Its immunomodulatory activity was measured by examining the production of nitric oxide(NO) and cytokine secretion, and via lymphocyte proliferation experiments. Its effects on the scavenging activities of hydroxyl radical, superoxide anion and reducing power were also measured.RESULTS: A water-soluble polysaccharide, Flammulina velutipes polysaccharide I-A(FVP I-A), was obtained with a molecular mass of 8.14×104Da determined by high performance gel permeation chromatography. An in vitro antioxidant assay indicated that FVP I-A could scavenge hydroxyl radical, superoxide anion and possessed reducing power and could largely promote NO production and augment the interleukin-1β, interleukin-6, and tumor necrosis factor-α secretion by RAW264.7 macrophages(P<0.05). Moreover, FVP I-A could promote lymphocyte proliferation(P<0.05), and synergistically enhance the augmentation of the proliferation of mouse lymphocytes by concanavalin A and lipopolysaccharides(P<0.01, P<0.05).CONCLUSION: The FVP I-A obtained from Flammulina velutipes possessed antioxidant activity and could enhance non-specific and specific immune responses in vitro.

Hospital Strain and COVID-19 Fatality—England,April 2020–March 2022

Summary What is already known about this topic?During the coronavirus disease 2019(COVID-19)pandemic,tremendous efforts have been made in countries to suppress epidemic peaks and strengthen hospital services to avoid hospital strain and ultimately reduce the risk of death from COVID-19.However,there is limited empirical evidence that hospital strain increases COVID-19 deaths.

Effect of edge cracks on critical current degradation in REBCO tapes under tensile stress

The slitting process for manufacturing REBa2Cu3O7
δ(REBCO,RE=Rare earth)tapes of required width significantly improves the production efficiency and reduces production costs.However,edge cracks induced by the slitting process of wide REBCO tapes may cause premature degradation under high tensile stress in highfield magnets.Therefore,it is necessary to evaluate the effect of edge cracks of REBCO tapes on the critical current(Ic)degradation.Firstly,Ic degradation under artificial cracks was measured to validate the applicability of linear elastic fracture mechanics for the REBCO layer.The maximum circumferential stress criterion was used to derive the mixed-mode stress intensity factor of multiple oblique edge cracks.A semi-analytical model considering edge crack properties such as angleβ,spacing d,and length a,was built to evaluate the critical load and critical crack.We found that when the stress intensity factor at the crack tip is below KIC?2:3 MPa ffiffiffiffim p,edge cracks did not propagate.We examined commercial REBCO tapes manufactured by two different processes,concluding that edge cracks in these tapes will not cause premature degradation.

Characteristics and Containment of 74 Imported COVID-19 Outbreaks: Experiences, Lessons, and Implications — China, 2020–2021

What is already known about this topic?After the initial coronavirus disease 2019(COVID-19)outbreak in Wuhan,China,the outbreaks during the dynamic-zero policy period in the mainland of China have not been systematically documented.What is added by this report?We summarized the characteristics of 74 imported COVID-19 outbreaks between March 19,2020 and December 31,2021.All outbreaks of early severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variants were successfully contained with the aid of nucleic acid testing,modern communication technologies,and non-pharmacological interventions.What are the implications for public health practice?These findings provide us with confidence for the containment of future emerging infectious diseases alike at early stages to prevent pandemics or to win time to gain experience,develop vaccines and drugs,vaccinate people,and wait for the possible lessening of the virus’pathogenicity.

Orthogonal nonnegative learning for sparse feature extraction and approximate combinatorial optimization

Nonnegativity has been shown to be a powerful principle in linear matrix decompositions,leading to sparse component matrices in feature analysis and data compression.The classical method is Lee and Seung’s Nonnegative Matrix Factorization.A standard way to form learning rules is by multiplicative updates,maintaining nonnegativity.Here,a generic principle is presented for forming multiplicative update rules,which integrate an orthonormality constraint into nonnegative learning.The principle,called Orthogonal Nonnegative Learning(ONL),is rigorously derived from the Lagrangian technique.As examples,the proposed method is applied for transforming Nonnegative Matrix Factorization(NMF)and its variant,Projective Nonnegative Matrix Factorization(PNMF),into their orthogonal versions.In general,it is well-known that orthogonal nonnegative learning can give very useful approximative solutions for problems involving non-vectorial data,for example,binary solutions.Combinatorial optimization is replaced by continuous-space gradient optimization which is often computationally lighter.It is shown how the multiplicative updates rules obtained by using the proposed ONL principle can find a nonnegative and highly orthogonal matrix for an approximated graph partitioning problem.The empirical results on various graphs indicate that our nonnegative learning algorithms not only outperform those without the orthogonality condition,but also surpass other existing partitioning approaches.