First-principles study on the co-adsorption of water and oxygen molecules on chalcopyrite(112)-M surface

Chalcopyrite is a common copper-bearing mineral with antiferromagnetic properties.However,this property has rarely been considered in previous studies for detailed adsorption behaviors of molecules on chalcopyrite.Based on density functional theory(DFT),new adsorption pathways by H_(2)O and O_(2)on the chalcopyrite metal terminated(112)surface((112)-M)is found in this work.First,through simulating the adsorption of an isolated water molecule and monolayer water molecules,it is confirmed that H_(2)O molecules tend to adsorb on the surface Fe atoms more than on the surface Cu atoms.Then,we studied various adsorption behaviors of the O_(2)molecule.It is found that the adsorption on the hollow FeAFe site is the most stable case;however,O_(2)is undissociated.Two adsorption cases will happen when H_(2)OAO_(2)adsorb simultaneously on the surface.For the S site,the H_(2)O molecule thoroughly dissociated and formed SAO species,and the other case is H_(2)O undissociated adsorbing at the Cu site.For the former case,it is interesting that H_(2)O is dissociated before O_(2).

Simultaneous measurements of refractive index and temperature based on a no-core fiber coated with Ag and PDMS films

A compact surface plasmon resonance(SPR) fiber optic sensor, being utilized to simultaneously measure refractive index(RI) and temperature, is proposed and experimentally demonstrated in this paper. One part of a no-core fiber(NCF)was coated with a silver(Ag) film, and the other part was coated with a silver/polydimethylsiloxane(Ag/PDMS) composite film to stimulate the SPR effect. Due to the two heterogeneous films, two dips appeared in the transmission spectrum and were used to achieve the dual-parameter measurements. The experimental results showed that the RI sensitivity reached 2121.43 nm/RIU and 0 nm/RIU, while the temperature sensitivity reached-0.32 nm/℃ and-2.21 nm/℃ for the two dips,respectively. Based on the obtained transfer matrix, the measurements of RI and temperature could be demodulated. This designed sensor showed the merits of simple structure, easy to implement, and high sensitivity, demonstrating application prospects in dual-parameter monitoring.

Consideration of transmembrane water exchange in pharmacokinetic model significantly improves the accuracy of DCE-MRI in estimating cellular density:A pilot study in glioblastoma multiforme

Transmembrane water exchange(TWE)including transcytolemmal water exchange and transvascular water exchange is involved in many in vivo measurements and makes different contributions to the measuring results.In this study,we focus on the potential influence of TWE on the cell density parameter,intracellular water mole fraction pi,derived by dynamic contrast enhanced-magnetic resonance imaging(DCE-MRI)which has been reported as a technique to characterize perfusion and vascularization of tissues,but its accuracy in measuring cell density(or interstitial space)has been questioned.Sixteen patients with glioblastoma multiforme(GBM)were enrolled since GBM shows strong intratumor heterogeneity in both cell density and TWE.All the subjects were collected with DCE-MRI and apparent diffusion coefficient(ADC)map.The latter was considered as a valid surrogate of cell density.Extended Tofts(eTofts)model considering TWE as infinitely large variables and shutter-speed model(SSM)considering TWE as finite ones were used to fit DCE-MRI data.Monte Carlo(MC)and finite difference(FD)methods were used to simulate the influence of TWE on DCE-MRI-derived pi and ADC,respectively.The eTofts model shows a significant overestimation of pi in comparison with SSM in GBM(P<0.001),which is in accordance with MC simulations,and this overestimation shows dependence on the intra-to-extracellular water exchange rate constant(kio).Significant negative correlations between ADC and SSM-derived pi were found in both voxel-wise analyses(t-test P<0.001,average r=-0.74)and inter-subject comparisons(r=-0.63,P=0.009).But no consistent voxel-wise correlations(P>0.05)and a weaker inter-subject negative correlation(r=-0.56,P=0.02)were found between ADC and eTofts-derived pi.Further experimental and FD results revealed that kio made a limited contribution to ADC values in the physiological kio range in GBM,supporting ADC as a valid biomarker of cell density.These results suggest that the DCE-MRI pharmacokinetic shutter-speed model could significantly improve its accuracy in cell density estimation because of the considering transmembrane water exchange.

A multi-parameter-induced activation of gas therapeutic platform to remarkably amplify photodynamic therapy efficacy

Gas therapy(GT)combined with photodynamic therapy(PDT)is an effective strategy to compensate for the PDT limitation caused by the hypoxic tumor microenvironment,which can greatly improve PDT efficacy.The uncontrolled leakage of gas molecules during delivery seriously hinders its practical biological application.Herein,we report a multifunction nanomedicine that enables precise gas therapy(including carbon monoxide(CO)release and H_(2)S depletion)using a multi-parameter-induced activation gas release strategy,enlarging the PDT efficacy.This nanomedicine uses a disulfide bond to covalently link a photosensitizer with the CO donor 3-hydroxyflavone(3-HF).The disulfide bond can be specifically consumed in H_(2)S-rich tumor areas,releasing the CO donor(3-HF),and also depleting H_(2)S.More importantly,the photo-controlled production of^(1)O_(2)can induce 3-HF precise release of CO in the tumor location.Such H_(2)S,light,and^(1)O_(2)multi-parameter-induced activation of gas release strategy ensures the accuracy of GT to amplify PDT efficiency.As expected,in vitro and in vivo investigations show that GT makes up for the PDT limitation,exhibiting the highest tumor therapeutic effect.This multi-parameter-activated design strategy provides a new way to improve the precision and efficacy of multimodal synergistic therapy of tumors.

Intermolecular hydrogen-bonding as a robust tool toward significantly improving the photothermal conversion efficiency of a NIR-II squaraine dye

The photothermal therapy(PTT) has come across as a promising noninvasive therapeutic strategy for tumor treatment. However, low photothermal conversion efficiency(PCE) and hydrophobicity may impede the therapeutic efficacy of organic photothermal agents and an efficient PTT-agent must overcome these two major challenges. In this work, we developed a new strategy to promote higher PCE wherein the intermolecular hydrogen-bonding interaction between the single dye molecule and water facilitated the transformation of the absorbed energy into the heat. A hydrophilic squaraine dye(SCy1) with the second near-infrared region(NIR-II) absorption and extremely low emission were designed to exhibit much higher PCE than that of the analogues of pentamethine-dyes(PCy1, PCy2). The presence of the ‘–O-' at middle of squaric cycle enabled the intermolecular H-bonding formation between the SCy1 and water to promote the energy dissipation channel. Moreover, the introduction of long-chain phenylsulfonate groups helped in to improve the water solubility apart from serving as an additional means of further enhancing PCE through fluorescence quenching. Therefore, SCy1 with a squaraine backbone and long-chain sulfonate moieties revealed outstanding photothermal stability and anti-aggregation activity apart from showing exceptionally high PCE(74%) in water. SCy1 demonstrated excellent therapeutic efficacy when applied in the PTT treatment of tumor-bearing mice under a laser irradiation of 915 nm.

Current situation and prospect for the diagnosis and treatment of pediatric critical rare diseases in China

The onset of critical rare diseases(RDs)in children is rapid and dangerous,accompanied by a high mortality rate,which brings a heavy burden to both families and society.Multiple malformations,neuromuscular diseases,metabolic diseases,and heart diseases are the most common types of RDs in children of China,often manifesting with multiple organ dysfunction.At present,the diagnosis and treatment of critical RDs in children face challenges such as prolonged diagnosis time,a high misdiagnosis rate,limited treatment modalities,and a significant disease burden.However,with the progress in genetic testing technology,the establishment of multidisciplinary diagnosis and treatment platforms,and the implementation of relevant RD policies in China,children with critical RDs will received enhanced medical services,experience improved prognoses,and reintegrate into social life.

中国沉积岩容矿铅锌矿床中的关键金属

沉积岩容矿铅锌矿床主要包括碎屑岩赋矿(clastic-dominated,CD)矿床和密西西比河谷型(Mississippi-Valley type,MVT)矿床两种,它是世界上Cd、Ga、Ge等关键金属的重要来源,并具有In、Co、Tl的资源潜力.中国沉积岩容矿铅锌矿床主要分布在5个成矿区/带,提供了全国54%的铅锌用量,但其伴生关键金属的资源潜力和成矿机制尚不清楚.本文在综述沉积岩容矿铅锌矿床中伴生的主要关键金属和中国沉积岩容矿铅锌矿床的基础上,详细总结了中国沉积岩容矿铅锌矿床中关键金属的分布特征和富集机制.各类关键金属元素在中国沉积岩容矿铅锌矿床中分布不均,相对地壳丰度,Cd、Ge、In最为富集,Tl、Co有一定富集,Ga的富集程度较低;从矿床类型上来看,Cd、Ga、Ge、Tl在中国MVT矿床中相对富集,In、Co在CD矿床中相对富集;从区域分布上来看,不同元素的富集区带差异很大,除Cd在5个成矿区/带都有较好富集外,其他金属在三江带、扬子地台、厂坝成矿带出现不同程度富集.总结发现,沉积岩容矿铅锌矿床对所富集关键金属的种类具选择性,而关键金属在该类矿床中的富集程度也具差异性.前者主要由关键金属元素同矿床中相关矿物组成元素(主要为Zn和Fe)的地球化学相似性导致,后者则由关键金属进入赋存矿物的替代形式、成矿流体的物理化学条件、成矿背景导致.目前,中国沉积岩容矿铅锌矿床伴生关键金属的研究尚处于起步阶段,建立相关资源数据库,深入开展富集成矿机制研究,厘定不同铅锌成矿区/带关键金属的区域成矿规律是亟须开展的工作.

Non-specific/specific SERS spectra concatenation for precise bacteria classifications with few samples using a residual neural network

Deep learning neural network incorporating surface enhancement Raman scattering technique(SERS)is becoming as a powerful tool for the precise classifications and diagnosis of bacterial infections.However,the large amount of sample requirement and time-consuming sample collection severely hinder its applications.We herein propose a spectral concatenation strategy for residual neural network using nonspecific and specific SERS spectra for the training data augmentation,which is accessible to acquiring larger training dataset with same number of SERS spectra or same size of training dataset with fewer SERS spectra,compared with pure non-specific SERS spectra.With this strategy,the training loss exhibit rapid convergence,and an average accuracy up to 100%in bacteria classifications was achieved with50 SERS spectra for each kind of bacterium;even reduced to 20 SERS spectra per kind of bacterium,classification accuracy is still>95%,demonstrating marked advantage over the results without spectra concatenation.This method can markedly improve the classification accuracy under fewer samples and reduce the data collection workload,and can evidently enhance the performance when used in different machine learning models with high generalization ability.Therefore,this strategy is beneficial for rapid and accurate bacteria classifications with residual neural network.

Clonal and drug resistance dynamics of methicillin-resistant Staphylococcus aureus in pediatric populations in China

Importance:Regional clonal replacements of methicillin-resistant Staphylococcus aureus (MRSA) are common.It is necessary to understand the clonal and drug resistance changes in specific areas.Objective:To evaluate the clonal and drug resistance dynamics of MRSA in Chinese children from 2010 to 2017.Methods:MRSA was isolated from patients in Beijing Children's Hospital from 2010 to 2013 and from 2016 to 2017.The molecular characteristics and antibiotic resistance were determined,Results:In total,211 MRSA isolates were collected,and 104 isolates were classified as community-associated MRSA (CA-MRSA).ST59-SCCmec Ⅳ was the most prevalent type in both CA-MRSA (65.4%) and healthcare-associated-MRSA (HA-MRSA) (46.7%).ST239-SCCmec Ⅲ accounted for 21.5% of all HA-MRSA,which were not detected in 2016,and only three isolates were detected in 2017.The pvl gene carrying rate of CA-MRSA was significantly higher than that of HA-MRSA (42.3% vs.29.0%,P =0.0456).Among CA-MRSA,resistance rate to all tested antibiotics excluding chloramphenicol remained stable over the periods of 2010-2013 and 2016-2017.HA-MRSA displayed an overall trend of decreased resistance to oxacillin,gentamicin,tetracycline,ciprofloxacin,and rifampin,and increased resistance to chloramphenicol,consistent with the difference of antibiotic resistance patterns between ST59-SCCmec Ⅳ and ST239-SCCmec Ⅲ isolates.Vancomycin minimal inhibitory concentration (MIC) creep was found in the study period in all MRSA and ST59-SCCmec Ⅳ isolates.Interpretation:ST59-SCCmec Ⅳ has spread to hospitals and replaced the traditional ST239-SCCmec Ⅲ clone,accompanied by changes in drug resistance.Furthermore,vancomycin MIC creep indicated that the rational use of antibiotics should be seriously considered.

Palynological constraints on the age of the Mississippi Valley-type Changdong Pb-Zn deposit,Sanjiang belt,West China

Mississippi Valley-type(MVT)Pb-Zn deposits serve as the world’s major supply of Pb-Zn resources.However,the age constraint of MVT Pb-Zn deposits has long been a big challenge,due to the lack of minerals that are unequivocally related to ore deposition and that can be used for radioisotopic dating.Here we show sporopollens can provide useful chronological information on the Changdong MVT Pb-Zn deposit in the Simao basin,Sanjiang belt,West China.The Pb-Zn ores in the Changdong deposit are hosted by internal sediments in paleo-karst caves of meteoric origin.Sphalerite and galena occur as replacements of carbonate minerals and void infillings in the internal sediments.The relations suggest that the Pb-Zn mineralization occurred after the deposition of the internal sediments.A palynological assemblage mainly composed of angiosperm pollen dominated by Castanea,Quercus,and Carya and fern spores dominated by Polypodiaceae,Pteris,and Athyriaceae was identified.These pollen and spores place the ore-hosting internal sediments and the Changdong paleo-karst at early to middle Oligocene.Consequently,the Changdong Pb-Zn deposit must have formed after the early Oligocene(~34 Ma).These age constraints,together with the geological characteristics,indicate that the Changdong Pb-Zn deposit is a paleo-karst-controlled MVT deposit related to fold-thrust systems in the Sanjiang belt.The Changdong deposit is similar to other MVT Pb-Zn deposits in the northern part of the Sanjiang belt,making it possible to extend this Pb-Zn belt 500 km further to the South.Results presented here highlights the potential of sporopollens in dating the age of MVT deposits related to paleo-karst formation in young orogenic belts.

Flexoelectricity Driven Fano Resonance in Slotted Carbon Nanotubes for Decoupled Multifunctional Sensing

Multifunctionality,interference-free signal readout,and quantum effect are important considerations for flexible sensors equipped within a single unit towards further miniaturization.To address these criteria,we present the slotted carbon nanotube(CNT)junction features tunable Fano resonance driven by flexoelectricity,which could serve as an ideal multimodal sensory receptor.Based on extensive ab initio calculations,we find that the effective Fano factor can be used as a temperature-insensitive extrinsic variable for sensing the bending strain,and the Seebeck coefficient can be used as a strain-insensitive intrinsic variable for detecting temperature.Thus,this dual-parameter permits simultaneous sensing of temperature and strain without signal interference.We further demonstrate the applicability of this slotted junction to ultrasensitive chemical sensing which enables precise determination of donor-type,acceptor-type,and inert molecules.This is due to the enhancement or counterbalance between flexoelectric and chemical gating.Flexoelectric gating would preserve the electron–hole symmetry of the slotted junction whereas chemical gating would break it.As a proof-of-concept demonstration,the slotted CNT junction provides an excellent quantum platform for the development of multistimuli sensation in artificial intelligence at the molecular scale.

Flexoelectricity Driven Fano Resonance in Slotted Carbon Nanotubes for Decoupled Multifunctional Sensing

Mulifunctionality,interference fre signal readout,and quantum eft are important considerations for flexible sensors equipped within a single unit towards further miniaturization.To address these criteria,we present the slotted carbon nanotube(CNT)junction features lunable Fano resonance driven by flexoelectricity,which could serve as an ideal multimodal sensory receptor.Based on extensive ab initio calculations,we find that the efective Fano factor can be used as a temperature insensitive extrinsic variable for sensing the bending strain,and the Seebeck cefficient can be used as a strain-insensitive intrinsic variable for detecting temperalure.Thus,this dual parameter permits simultaneous sensing of temperature and strain without signal interference.We further demonstrale the applcability of this slotted junction to ultrasensitive chemical sensing which enables precise determination of donor type.acceptor type.and inert molecules.This is due to the enhancement or counterbalance between flexoelectric and chemical gating.Flexoelectric gating would preserve the electron-hole symmetry of the slotted junction whereas chemical gating would break it.As a proof-of-concept demonstration,the slotted CNT junction provides an excellent quantum platform for the development of mulistimuli sensation in artificial itelligence at the molecular scale.

Plasma exchange therapy for acute necrotizing encephalopathy of childhood

Importance Acute necrotizing encephalopathy(ANE)is a rare disease with high mortality.Plasma exchange(PLEX)has recently been reported to treat ANE of childhood(ANEC),but its efficacy is uncertain.Objective This study aimed to investigate the effectiveness of PLEX on ANEC.Methods A retrospective study was conducted in four pediatric intensive care units from December 2014 to December 2020.All patients who were diagnosed with ANEC were included;however,these patients were excluded if their length of stay was less than 24 h.Participants were classified into PLEX and non-PLEX groups.Results Twenty-nine patients with ANEC were identified,10 in the PLEX group and 19 in the non-PLEX group.In the PLEX group,C-reactive protein,procalcitonin,alanine aminotransferase,and aspartate aminotransaminase levels were significantly lower after 3 days of treatment than before treatment(13.1 vs.8.0,P=0.043;9.8 vs.1.5,P=0.028;133.4 vs.31.9,P=0.028;282.4 vs.50.5,P=0.046,respectively).Nine patients(31.0%,9/29)died at discharge,and a significantly difference was found between the PLEX group and non-PLEX group[0 vs.47.4%(9/19),P=0.011].The median follow-up period was 27 months,and three patients were lost to follow-up.Thirteen patients(50.0%,13/26)died at the last follow-up,comprising three(33.3%,3/9)in the PLEX group and ten(58.8%,10/17)in the non-PLEX group,but there was no significant difference between the two groups(P=0.411).Three patients(10.3%,3/29)fully recovered.Interpretation PLEX may reduce serum C-reactive protein and procalcitonin levels and improve liver function in the short term.PLEX may improve the prognosis of ANEC,and further studies are needed.