Power Allocation and Antenna Selection for Heterogeneous Cellular Networks

In this paper,we investigate the system performance of a heterogeneous cellular network consisting of a macro cell and a small cell,where each cell has one user and one base station with multiple antennas.The macro base station(MBS)and the small base station(SBS)transmit their confidential messages to the macro user(MU)and the small user(SU)over their shared spectrum respectively.To enhance the system sum rate(SSR)of MBS-MU and SBS-SU transmission,we propose joint antenna selection combined with optimal power allocation(JAS-OPA)scheme and independent antenna selection combined with optimal power allocation(IAS-OPA)scheme.The JAS-OPA scheme requires to know the channel state information(CSI)of transmission channels and interference channels,while the IAS-OPA scheme only needs to know the CSI of transmission channels.In addition,we carry out the analysis for conventional round-robin antenna selection combined with optimal power allocation(RR-OPA)as a benchmark scheme.We formulate the SSR maximization problem through the power allocation between MBS and SBS and propose iterative OPA algorithms for JAS-OPA,IAS-OPA and RR-OPA schemes,respectively.The results show that the OPA schemes outperform the equal power allocation in terms of SSR.Moreover,we provide the closed-form expression of the system outage probability(SOP)for IAS scheme and RR scheme,it shows the SOP performance can be significantly improved by our proposed IAS scheme compared with RR scheme.

The parallel biosynthesis routes of hyperoside from naringenin in Hypericum monogynum

Hyperoside is a bioactive flavonoid galactoside in both medicinal and edible plants.It plays an important physiological role in the growth of flower buds.However,the hyperoside biosynthesis pathway has not been systematically elucidated in plants,including its original source,Hypericaceae.Our group found abundant hyperoside in the flower buds of Hypericum monogynum,and we sequenced its transcriptome to study the biosynthetic mechanism of hyperoside.After gene screening and functional verification,four kinds of key enzymes were identified.Specifically,HmF3Hs(flavanone 3-hydroxylases)and HmFLSs(flavonol synthases)could catalyze flavanones into dihydroflavonols,as well as catalyzing dihydroflavonols into flavonols.HmFLSs could also convert flavanones into flavonols and flavones with varying efficiencies.HmF3′H(flavonoid 3′-hydroxylase)was found to act broadly on 4′-hydroxyl flavonoids to produce 3′,4′-diydroxylated flavanones,dihydroflavonols,flavonols,and flavones.HmGAT(flavonoid 3-O-galactosyltransferase)would transform flavonols into the corresponding 3-O-galactosides,including hyperoside.The parallel hyperoside biosynthesis routes were thus depicted,one of which was successfully reconstructed in Escherichia coli BL21(DE3)by feeding naringenin,resulting in a hyperoside yield of 25 mg/l.Overall,this research not only helped us understand the interior catalytic mechanism of hyperoside in H.monogynum concerning flower development and bioactivity,but also provided valuable insights into these enzyme families.

Exosomes derived from pulmonary metastatic sites enhance osteosarcoma lung metastasis by transferring the miR-194/215 cluster targeting MARCKS

Osteosarcoma,a prevalent primary malignant bone tumor,often presents with lung metastases,severely impacting patient survival rates.Extracellular vesicles,particularly exosomes,play a pivotal role in the formation and progression of osteosarcoma-related pulmonary lesions.However,the communication between primary osteosarcoma and exosome-mediated pulmonary lesions remains obscure,with the potential impact of pulmonary metastatic foci on osteosarcoma progression largely unknown.This study unveils an innovative mechanism by which exosomes originating from osteosarcoma pulmonary metastatic sites transport the miR-194/215 cluster to the primary tumor site.This transportation enhances lung metastatic capability by downregulating myristoylated alanine-rich C-kinase substrate(MARCKS)expression.Addressing this phenomenon,in this study we employ cationic bovine serum albumin(CBSA)to form nanoparticles(CBSA-anta-194/215)via electrostatic interaction with antagomir-miR-194/215.These nanoparticles are loaded into nucleic acid-depleted exosomal membrane vesicles(anta-194/215@Exo)targeting osteosarcoma lung metastatic sites.Intervention with bioengineered exosome mimetics(anta-194/215@Exo)not only impedes osteosarcoma progression but also significantly prolongs the lifespan of tumor-bearing mice.These findings suggest that pulmonary metastatic foci-derived exosomes initiate primary osteosarcoma lung metastasis by transferring the miR-194/215 cluster targeting MARCKS,making the miR-194/215 cluster a promising therapeutic target for inhibiting the progression of patients with osteosarcoma lung metastases.

Two types of coumarins-specific enzymes complete the last missing steps in pyran- and furanocoumarins biosynthesis

Pyran-and furanocoumarins are key representatives of tetrahydropyrans and tetrahydrofurans,respectively,exhibiting diverse physiological and medical bioactivities.However,the biosynthetic mechanisms for their core structures remain poorly understood.Here we combined multiomics analyses of biosynthetic enzymes in Peucedanum praeruptorum and in vitro functional verification and identified two types of key enzymes critical for pyran and furan ring biosynthesis in plants.These included three distinct P.praeruptorum prenyltransferases(PpPT1e3)responsible for the prenylation of the simple coumarin skeleton 7 into linear or angular precursors,and two novel CYP450 cyclases(PpDC and PpOC)crucial for the cyclization of the linear/angular precursors into either tetrahydropyran or tetrahydrofuran scaffolds.Biochemical analyses of cyclases indicated that acid/base-assisted epoxide ring opening contributed to the enzyme-catalyzed tetrahydropyran and tetrahydrofuran ring refactoring.The possible acid/base-assisted catalytic mechanisms of the identified cyclases were theoretically investigated and assessed using site-specific mutagenesis.We identified two possible acidic amino acids Glu303 in PpDC and Asp301 in PpOC as vital in the catalytic process.This study provides new enzymatic tools in the epoxide formation/epoxide-opening mediated cascade reaction and exemplifies how plants become chemically diverse in terms of enzyme function and catalytic process.

LIX1-like protein promotes liver cancer progression via miR-21-3p-mediated inhibition of fructose-1,6-bisphosphatase

Limb and CNS expressed 1 like(LIX1L) is over-expressed in several types of tumors.However,the function of LIX1L in glucose metabolism and hepatocellular carcinoma(HCC) progression remains elusive.Here we report that LIX1L is over-expressed in human HCC tissues,which predicts unfavorable prognosis.LIX1L deficiency in vivo significantly attenuated liver cancer initiation in mice.Functional studies indicated that LIX1L overexpression elevated proliferation,migratory,invasive capacities of HCC cells in vitro,and promoted liver cancer growth and metastasis in vivo.LIX1L knockdown up-regulated fructose-1,6-bisphosphatase(FBP1) expression to reduce glucose consumption as well as lactate production.Mechanistically,LIX1L increased miR-21-3p expression,which targeted and suppressed FBP1,thereby promoting HCC growth and metastasis.MiR-21-3p inhibitor could abrogate LIX1L induced enhancement of cell migration,invasion,and glucose metabolism.Inhibition of miR-21-3p suppressed tumor growth in an orthotopic tumor model.Our results establish LIX1L as a critical driver of hepatocarcinogenesis and HCC progression,with implications for prognosis and treatment.

Spirolindemers A and B,Lindenane Sesquiterpenoid Oligomers Equipped with Oxaspiro[4.5]decane from Chloranthus henryi

Spirolindemers A and B,unprecedented lindenane sesquiterpenoid dimer(1)and trimer(2)equipped with oxaspiro[4.5]decane unit,were discovered from the medicinal plant Chloranthus henryi.Their structures including absolute configurations were achieved by HRMS,NMR,ECD,X-ray diffraction analyses,and quantum chemical calculations.Biogenetically,hetero-and homo-Diels-Alder additions may dominate the formation of oxaspiro[4.5]decane and spiro[4.5]decane skeletons,respectively.Compound 1 showed anti-inflammatory activity by inhibiting the expression of iNOS and COX-2.

Identification of a novel PHGDH covalent inhibitor by chemical proteomics and phenotypic profiling

The first rate-limiting enzyme of the serine synthesis pathway(SSP), phosphoglycerate dehydrogenase(PHGDH), is hyperactive in multiple tumors, which leads to the activation of SSP and promotes tumorigenesis. However, only a few inhibitors of PHGDH have been discovered to date, especially the covalent inhibitors of PHGDH. Here, we identified withangulatin A(WA), a natural small molecule,as a novel covalent inhibitor of PHGDH. Affinity-based protein profiling identified that WA could directly bind to PHGDH and inactivate the enzyme activity of PHGDH. Biolayer interferometry and LC-MS/MS analysis further demonstrated the selective covalent binding of WA to the cysteine 295 residue(Cys295)of PHGDH. With the covalent modification of Cys295, WA blocked the substrate-binding domain(SBD)of PHGDH and exerted an allosteric effect to induce PHGDH inactivation. Further studies revealed that with the inhibition of PHGDH mediated by WA, the glutathione synthesis was decreased and intracellular levels of reactive oxygen species(ROS) were elevated, leading to the inhibition of tumor proliferation.This study indicates WA as a novel PHGDH covalent inhibitor, which identifies Cys295 as a novel allosteric regulatory site of PHGDH and holds great potential in developing anti-tumor agents for targeting PHGDH.

Sarcaglarols A-D, Lindenane-Monoterpene Heterodimers from Sarcandra glabra Based on Molecular Networks

Sarcaglarols A-D(1-4),two pairs of lindenane-monoterpene heterodimers fused by a 1,2-dioxane moiety,were discovered and isolated from the leaves of Sarcandra glabra guided by MS/MS molecular networking-based strategy.Their planar structures,absolute configurations of basic skeleton and flexible polyhydric side chain were established by analysis of HRESIMS,NMR spectroscopic data,ECD spectrum,and the X-ray diffraction study of isopropylidene derivatives.An intermolecular[2+2+2]cycloaddition may play a key role in the biosynthesis pathway of the 1,2-dioxane moiety fused lindenane-monoterpene heterodimer skeleton,which can be recognized as the biogenetic precursors of our previous reported lindenane-normonoterpene conjugates.In addition,compounds 1,3 and 4 exhibited moderate inhibitory effects of lipid accumulation in free fatty acid-exposed L02 cells.

Enhanced tumor homing of pathogen-mimicking liposomes driven by R848 stimulation: A new platform for synergistic oncology therapy

Although multifarious tumor-targeting modifications of nanoparticulate systems have been attempted in joint efforts by our predecessors,it remains challenging for nanomedicine to traverse physiological barriers involving blood vessels,tissues,and cell barriers to thereafter demonstrate excellent antitumor effects.To further overcome these inherent obstacles,we designed and prepared mycoplasma membrane(MM)-fused liposomes(LPs)with the goal of employing circulating neutrophils with the advantage of inflammatory cytokine-guided autonomous tumor localization to transport nanoparticles.We also utilized in vivo neutrophil activation induced by the liposomal form of the immune activator resiquimod(LPsR848).Fused LPs preparations retained mycoplasma pathogen characteristics and achieved rapid recognition and endocytosis by activated neutrophils stimulated by LPs-R848.The enhanced neutrophil infiltration in homing of the inflammatory tumor microenvironment allowed more nanoparticles to be delivered into solid tumors.Facilitated by the formation of neutrophil extracellular traps(NETs),podophyllotoxin(POD)-loaded MM-fused LPs(MM-LPs-POD)were concomitantly released from neutrophils and subsequently engulfed by tumor cells during inflammation.MM-LPs-POD displayed superior suppression efficacy of tumor growth and lung metastasis in a 4T1 breast tumor model.Overall,such a strategy of pathogen-mimicking nanoparticles hijacking neutrophils in situ combined with enhanced neutrophil infiltration indeed elevates the potential of chemotherapeutics for tumor targeting therapy.

Correlation and interaction between temperature and freeze-thaw in representative regions of Antarctica

As the most sensitive and direct indicator of global climate change,the freezing and thawing of the Antarctic ice sheet is of great significance for research on surface mass and energy balance.In this study,four representative regions in Antarctica were selected and correlation analysis,Granger causality testing,and cluster analysis were applied to comprehensively analyze the correlation and response of spatiotemporal variation in freeze-thaw and temperature.The conclusions are as follows.(1)In the Antarctic Peninsula,a phenomenon was demonstrated that the summer shifts rearward.Hotter December and colder March temperatures were observed in the Amery Ice Shelf and Queen Maud Land.(2)The Antarctic Peninsula featured the most severe degree of melting among the four regions,with the largest melt area in the past 30 years appearing during the 2015/2016 season.However,the number of melt days in most areas of the Antarctic Peninsula was observed to have decreased.(3)There is a strong correlation between the freeze-thaw state of the Antarctic ice sheet and temperature,as well as spatial differences among regions,but the data were clustered at different time scales.

Pharmacokinetic study and metabolite identification of the bidesmosidic triterpenoid saponin BTS-1 in rat plasma

Assays based on high-performance liquid chromatography(HPLC)and liquid chromatography tandem mass spectrometry(LC–MSn)have been developed and validated for the determination and metabolite identification of the bidesmosidic triterpenoid saponin,BTS-1(3-O-β-D-galactopyranosyl-(1-2)-[β-D-xylopyranosyl-(1-3)]-β-D-glucuronopyranosyl gypsogenin 28-O-α-L-arabinopyranosyl-(1-3)-βD-xylopyranosyl-(1-4)-α-L-rhamnopyranosyl-(1-2)-β-D-fucopyranoside),in rat plasma.The assay was successfully applied to a pharmacokinetic study in rats given a single oral dose of BTS-1(400 mg/kg).The results indicated that the compound was rapidly absorbed(Tmax=1.2870.29 h,Cmax=37.475.6 mg/mL)and slowly eliminated(t1/2=13.276.6 h).In addition,secondary glycosides and aglycones of BTS-1 were detected and identified.Since these metabolites are known to be activeα-glucosidase inhibitors,they probably play an important role in mediating the pharmacological effects of the saponin.

Hyperbenzones A and B,two 1,2-seco and rearranged polycyclic polyprenylated acylphloroglucinols from Hypericum beanii

Two novel seco-polycyclic polyprenylated acylphloroglucinols(PPAPs),hyperbenzones A(1)and B(2),were isolated from the roots of Hypericum beanii,together with one known biosynthetic congener 3.Compound 1 incorporates a 6/5/5 ring system with an unprecedented spiro[bicyclo[3.3.0]octane-3,1'-cyclohexane]-2,2'-dione motif.The structures of 1 and 2 were determined by a combination of high resolution electrospray ionization mass spectroscopy(HRESIMS),nuclear magnetic resonance(NMR)spectroscopic analyses,gage-independent atomic orbital(GIAO)NMR chemical shift calculation with DP4+analyses,electronic circular dichroism(ECD)calculation,and X-ray diffraction analysis.A 1,2-seco retroClaisen rearrangement from a bicyclo[3.3.1]nonane PPAP precursor and following chemodivergent radical cascade cyclizations are proposed as the key steps in the biosynthetic pathway to yield compounds 1 and2.Biological investigations indicated that compounds 1 and 3 could decrease intracellular lipid accumulation in a palmitic acid-induced nonalcoholic steatohepatitis(NASH)cell model.

Elodexanthones A—J, Isoprenylated Xanthone Derivatives with Diverse Skeletons and Bioactivities from Hypericum elodeoides

Elodexanthones A—J (1—10), two pairs of rearranged isoprenylated xanthone enantiomers with an unprecedent 6/6/5/6 tetracyclic core (1—2) along with seven new isoprenylated xanthones (3—9) and a pair of phenylpropanoid xanthones (10), were purified and enantio-separated from the whole plant of Hypericum elodeoides. Their structures including absolute configurations were characterized by the comprehensive analysis of NMR, HRESIMS, NMR calculations, and ECD calculations. Through Bayer-Villiger oxidation, Claisen condensation and electrophilic addition, the rearranged skeletons of elodexanthones A—B (1—2) were generated from isoprenylated xanthone precursors. The bioactivities evaluation exhibited that compounds 3, 5, 8—10 showed anti-inflammatory activity with the IC_(50) values in the range of 9.53—34.39 μmol/L, and compounds 3—7, and 9 showed notable α-glucosidase inhibitory activity (IC_(50): 6.02—257.11 μmol/L).

Diverse Ring-seco Limonoids from Munronia unifoliolata and Their Biological Activities

Twenty-two new limonoids,mufolinoids A—V(1—22),including six rings A,B-seco limonoids(1—6),twelve ring A-seco limonoids(7—18),four ring-intact limonoids(19—22),together with thirteen known compounds(23—35)were isolated from Munronia unifoliolata.Their structures including absolute configurations were elucidated by combination of NMR,HR-MS,single-crystal X-ray diffraction and calculations of ECD and NMR technologies.Compounds 24,25,33,34 could be significantly reversed the multidrug resistance of MCF-7/doxorubicin(DOX)cells,and the reversal fold(RF)was much higher than that of positive drug Verapamil.Compounds 24,28,and 29 exhibited significant anti-inflammatory activity with the IC50 values in the range of 17.7—39.4μmol/L.Furthermore,compound 29 could markedly inhibit the release of IL-1βby inhibiting the initiation and assembly of NLRP3 inflammasome,which demonstrates the great potential of limonoids as an anti-inflammatory agent.

Bioactive A-ring rearranged limonoids from the root barks of Walsura robusta

Screening active natural products, rapid identification, and accurate isolation are of great important for modern natural lead compounds discovery1. We hereby reported the isolation of seven new neotecleanin-type limonoids(1–7), seven new limonoids with 5-oxatricyclo[5.4.0.11,4]hendecane ring system(8–14), and two new precursors(15–16) together with four known limonoids(17–20) from the root barks of Walsura robusta. Their structures, including their absolute configurations, were elucidated based on analyses of HR-ESI-MS, 1D/2D NMR, ECD spectrum calculations and singlecrystal X-ray diffraction techniques. Compounds 2, 8, 9, 11, 13, 14, 18 showed significant anti-inflammatory activities in LPS-induced RAW 264.7 cell line, BV2 microglial cells, and Propionibacterium acnes-stimulated THP-1 human monocytic cells. Walrobsin M(11) exhibited anti-inflammatory activity with IC50 value of 7.9670.36 μmol/L, and down-regulated phosphorylation levels of ERK and p38 in a dose-dependent manner.

Mufolinin A,an unprecedented ring A-seco 10-ethyllimonoid from Munronia unifoliolata

Mufolinin A(1),a ring A-seco rearranged limonoid with an unprecedented ethyl at C-10 and novel 6/6/6/5 fused-ring skeleton,together with three new potential precursors(ring A-seco limonoids,2–4)were isolated from Munronia unifoliolata.Their structures and absolute configurations were confirmed by nuclear magnetic resonance(NMR),high resolution electrospray ionization mass spectroscopy(HRESIMS),X-ray crystallography,electronic circular dichroism(ECD)calculations and NMR calculations with DP4+analyses.The unprecedented ethyl group of 1 was hypothesized to be derived from methyl migration and ring reduction rearrangement of ring A-seco limonoid 4.Compounds 2 and 4 showed significant multidrug resistance(MDR)reversal activities in MCF-7/DOX cells with reversal fold(RF)values of 13.1 and 8.0,respectively.

Efficient electrochemical reduction of CO to C_(2) products on the transition metal and boron co-doped black phosphorene

The synthesis of high-value multi-carbon products through the electrochemical reduction of carbon monoxide(COER) is one of the promising avenues for carbon utilization and energy storage,in which searching for efficient electrocatalysts that exhibit moderate CO intermediate binding strength and low kinetic barrier for C-C coupling is a key issue.Herein,by means of comprehensive density functional theory(DFT) computations,we theoretically designed three synergistic coupling catalysts by co-doping transition metal(TM=Fe,Co and Ni) and boron(B) into the two-dimensional black phosphorene(BP),namely TMB@BP for COER to C_(2) products.DFT computations and ab initio molecular dynamics simulations reveal the good stability and high feasibility of these proposed TM-B@BP catalysts for practical applications and future experimental synthesis.More interestingly,high-value ethylene(C_(2)H_(4)),ethane(C_(2)H_(6)) and ethanol(C_(2)H_(5)OH) products can be obtained on these three designed electrocatalysts with ultra-small limiting potentials(-0.20~-0.41 V) and low kinetic energy barriers of C-C coupling(0.52~0.91 eV).Meanwhile,the competitive one-carbon(C_(1)) products and hydrogen evolution reaction can also be effectively suppressed.The promising activity and selectivity of these three designed electrocatalysts render them ideal candidates for CO electroreduction,thus providing a cost-effective opportunity to achieve a sustainable production of high value C_(2) chemicals and fuels.

Chlospicenes A and B,cyclopropane cracked lindenane sesquiterpenoid dimers with anti-nonalcoholic steatohepatitis activity from Chloranthus henryi

Guided by MS/MS molecular networks strategy,chlospicenes A and B(1 and 2),the first example of cyclopropane moiety cracked lindenane sesquiterpene Michael addition dimers,along with their biogenetic analogues(3 and 4),were targetedly discovered from the roots of Chloranthus henryi.Their structures including absolute configurations were characterized by NMR,ECD and X-ray diffraction analysis.The plausible biogenic pathway speculation indicated that cyclopropylcarbinyl rearrangement may dominate the key crack of cyclopropane moiety.In addition,compounds 1 and 2 showed significant anti-nonalcoholic steatohepatitis(NASH)activity in free fatty acid(FFA)-induced HepG2 cells by decreasing intracellular lipid accumulation.

Aphamines A-C,dimeric acyclic diterpene enantiomers from Aphanamixis polystachya

Aphamines A-C(1-3),three pairs of acyclic diterpene dimer enantiomers with an unprecedent ploymerization pattern,were discovered from Aphanamixis polystachya by NMR-guided isolation and chiral resolution.The elucidation of their novel carbon skeletons was achieved based on spectroscopic analysis,exciton chirality,and calculated electronic circular dichroism(ECD).Plausible Claisen rearrangement,5-exo-trig cyclization,and reduction reactions may play important roles in the polymeric biosynthesis pathway.Compounds 1 and 3 showed inhibitory effects on nitric oxide(NO)production(IC_(50):6.71-15.36 μmol/L) and reduced the expression of iNOS in LPS-induced RAW 264.7 macrophages.

LIX1-like protein drives hepatic stellate cell activation to promote liver fibrosis by regulation of chemokine mRNA stability

Dear Editor,Hepatic stellate cells(HSCs)play a key role in the fibrotic response,thus inactivating activated HSC could be a potential therapy for fibrosis.^(1,2) CCL20 expressed by HSCs and macrophages,may serve as a mediator of in flammation and fibrosis.^(3) LIX1L is a putative RNA-binding protein(RBP)that may play an important role in post-transcriptional gene regulation.^(4) However,the biological function of LIX1L in liver fibrosis remains unclear,we therefore aimed to characterize its functions in HSC activation and liver fibrosis.