Synergistic and antagonistic interactions between potassium and magnesium in higher plants

Magnesium(Mg)affects various critical physiological and biochemical processes in higher plants,and its deficiency impedes plant growth and development.Although potassium(K)-induced Mg deficiency in agricultural production is widespread,the specific relationship of K with Mg and especially its competitive nature is poorly understood.This review summarizes current knowledge on the interactions between K and Mg with respect to their root uptake,root-to-shoot translocation and distribution in plants.Their synergistic effects on certain physiological functions are also described.The antagonistic effect of K on Mg is stronger than that of Mg on K in root absorption and transport within plants,indicating that the balanced use of K and Mg fertilizers is necessary for sustaining high plant-available Mg and alleviating K-induced Mg deficiency,especially in plant species with high K demand or in highavailable-K soil.The relationship between Mg and K in plant tissues may be antagonistic or synergistic depending on plant species,cell type,leaf age,source-and sink organs.There are synergistic effects of K and Mg on photosynthesis,carbohydrate transport and allocation,nitrogen metabolism,and turgor regulation.Definition of optimal K/Mg ratios for soils and plant tissues is desirable for maintaining proper nutritional status in plants,leading to a physiological state supporting crop production.Future research should concentrate on identifying the physiological and molecular mechanisms underlying the interactions between K and Mg in a given physiological function.

Functions of silicon in plant drought stress responses

Silicon(Si),the second most abundant element in Earth’s crust,exerts beneficial effects on the growth and productivity of a variety of plant species under various environmental conditions.However,the benefits of Si and its importance to plants are controversial due to differences among the species,genotypes,and the environmental conditions.Although Si has been widely reported to alleviate plant drought stress in both the Si-accumulating and nonaccumulating plants,the underlying mechanisms through which Si improves plant water status and maintains water balance remain unclear.The aim of this review is to summarize the morphoanatomical,physiological,biochemical,and molecular processes that are involved in plant water status that are regulated by Si in response to drought stress,especially the integrated modulation of Si-triggered drought stress responses in Si accumulators and intermediate-and excluder-type plants.The key mechanisms influencing the ability of Si to mitigate the effects of drought stress include enhancing water uptake and transport,regulating stomatal behavior and transpirational water loss,accumulating solutes and osmoregulatory substances,and inducing plant defense-associated with signaling events,consequently maintaining whole-plant water balance.This study evaluates the ability of Si to maintain water balance under drought stress conditions and suggests future research that is needed to implement the use of Si in agriculture.Considering the complex relationships between Si and different plant species,genotypes,and the environment,detailed studies are needed to understand the interactions between Si and plant responses under stress conditions.

Propelling polysulfide redox by Fe_(3)C-FeN heterostructure@nitrogendoped carbon framework towards high-efficiency Li-S batteries

Lithium-sulfur(Li-S) batteries hold great promise in next-generation high-energy-density energy storage systems,but the intractable shuttle effect and the sluggish redox kinetics of polysulfides hinder the practical implementation of Li-S batteries.Here,heterostructured Fe_(3)C-FeN nanoparticles dotted in the threedimensional-ordered nitrogen-doped carbon framework(Fe_(3)C-FeN@NCF) were synthesized by molecular engineering combined with heterointerface engineering,and were applied to regulate the immobilization-diffusion-conversion behavior of polar polysulfides.It is experimentally and theoretically demonstrated that the heterointerface between Fe_(3)C and FeN exhibits high sulfiphilicity and high electronic/ionic conductivity,thus effectively capturing polysulfides and accelerating the bidirectional conversion of sulfur species.Meanwhile,the holey carbon framework functions as the scaffold to highly disperse binary nanoparticles,ensuring the sufficient exposure of active sites and the easy accessibility for lithium ions and electrons.By virtue of these synergistic merits,the Li-S batteries based on Fe_(3)CFeN@NCF-modified separators afford excellent electrochemical performances including a high rate capacity of 858 mA h g^(-1)at 2 C and a low capacity decay rate of 0.07% per cycle after 800 cycles at 1C This work provides inspiration for the design of heterostructured compounds and sheds light on the potential of heterostructure in high-efficiency Li-S batteries.

Effects of Local Nitrogen Supply on Water Uptake of Bean Plants in a Split Root System

To study the effects of local nitrogen supply on water and nutrient absorption, French bean （Phaseolus vulgaris L.） plants were grown in a split root system. Five treatments supplied with different nitrogen forms were compared： homogeneous nitrate （NN） and homogenous ammonium （AA） supply, spatially separated supply of nitrate and ammonium （NA）, half of the root system supplied with N-free nutrient solution, the other half with either nitrate （NO） or ammonium （AO）. The results showed that 10 d after onset of treatments, root dry matter （DM） in the nitratesupplied vessels treated with NA was more than two times higher than that in the ammonium-supplied vessels. Water uptake from the nitrate-supplied vessels treated with NA was 281% higher than under ammonium supply. In treatments NO and AO, the local supply of N resulted in clearly higher root DM, and water uptake from the nitratesupplied vessels was 82% higher than in the -N vessels. However, in AO plants, water uptake from the -N nutrient solution was 129% higher than from the ammonium-supplied vessels. This indicates a compensatory effect, which resulted in almost identical rates of total water uptake of treatments AA and AO, which had comparable shoot DM and leaf area. Ammonium supply reduced potassium and magnesium absorption. Water uptake was positively correlated with N, Mg and K uptake.

Identification and functional analysis of heterogeneous FOXP3^+ Treg cell subpopulations in human pancreatic ductal adenocarcinoma

CD4^＋ CD25^＋ regulatory T （Treg） cells express the transcription factor FOXP3 and play an essential role in preventing autoimmunity. Abundant Treg cell accumulation in tumors and tumor draining lymph nodes （TDLNs） has been reported to correlate with both poor and favorable prognosis in various cancers, which suggests that Tregs may have multiple effects on antitumor immunity. However, the heterogeneity of tumor- and TDLN-infiltrating Treg cells remains unclear. Here we provide heterogeneity analysis of tumor infiltrating human CD4^＋ Treg cells and their matched adjacent tissues and TDLNs. We defined three different subpopulations of tumor- and TDLN-infiltrating Treg cells by Helios and CCR8 expression in pancreatic ductal adenocarcinoma （PDAC） and confirmed their functional heterogeneity. Helios^＋ CCR8^＋ Treg cells with potent suppressor function and limited IL-2 and IFN-7 secretion were identified in tumors and TDLNs. On the contrary, Helios^- CCR8^- Treg cells have impaired suppressive activity, and elevated expression of pro-inflammatory cytokines. More advanced grades of PDAC have predominantly Helios^＋ CCR8^＋ Treg cells and few Helios^- CCR8^- Treg cells both in tumors and TDLNs that suggests poor prognosis. These data could help further define the role of Treg cells and their functional role in tumors and TDLNs.

GSTAR:an innovative software platform for processing space geodetic data at the observation level

To meet the demands for the data combination with multiple space geodetic techniques at the observation level,we developed a new software platform with high extensibility and computation efficiency,named space Geodetic SpatioTemporal data Analysis and Research software(GSTAR).Most of the modules in the GSTAR are coded in C++with object-oriented programming.The layered modular theory is adopted for the design of the software,and the antenna-based data architecture is proposed for users to construct personalized geodetic application scenarios easily.The initial performance of the GSTAR software is evaluated by processing the Global Navigation Satellite System(GNSS)data collected from 315 globally distributed stations over two and a half years.The accuracy of GNSS-based geodetic products is evaluated by comparing them with those released by International GNSS Service(IGS)Analysis Centers(AC).Taking the products released by European Space Agency(ESA)as reference,the Three-Dimension(3D)Root-Mean-Squares(RMS)of the orbit differences are 2.7/6.7/3.3/7.7/21.0 cm and the STandard Deviations(STD)of the clock differences are 19/48/16/32/25 ps for Global Positioning System(GPS),GLObal NAvigation Satellite System(GLONASS),Galileo navigation satellite system(Galileo),BeiDou Navigation Satellite System(BDS),Medium Earth Orbit(MEO),and BDS Inclined Geo-Synchronous Orbit(IGSO)satellites,respectively.The mean values of the X and Y components of the polar coordinate and the Length of Day(LOD)with respect to the International Earth Rotation and Reference Systems Service(IERS)14 C04 products are-17.6 microarc-second(μas),9.2μas,and 14.0μs/d.Compared to the IGS daily solution,the RMSs of the site position differences in the north/east/up direction are 1.6/1.5/3.9,3.8/2.4/7.6,2.5/2.4/7.9 and 2.7/2.3/7.4 mm for GPS-only,GLONASS-only,Galileo-only,and BDS-only solution,respectively.The RMSs of the differences of the tropospheric Zenith Path Delay(ZPD),the north gradients,and the east gradients are 5.8,0.9,and 0.9 mm with respect to the IGS products.The X and Y components of the geocenter motion estimated from GPS-only,Galileo-only,and BDS-only observations well agree with IGS products,while the Z component values are much nosier where anomalous harmonics in GNSS draconitic year can be found.The accuracies of the above products calculated by the GSTAR are comparable with those from different IGS ACs.Compared to the precise scientific orbit products,the 3D RMS of the orbit differences for the two Gravity Recovery and Climate Experiment Follow-on(GRACE-FO)satellites is below 1.5 cm by conducting Precise Point Positioning with Ambiguity Resolution(PPP-AR).In addition,a series of rapid data processing algorithms are developed,and the operation speed of the GSTAR software is 5.6 times faster than that of the Positioning and Navigation Data Analyst(PANDA)software for the quad-system precise orbit determination procedure.

Coupling of the chemical niche and microbiome in the rhizosphere:implications from watermelon grafting

Grafting is commonly used to overcome soilborne diseases. However, its effects on the rhizodeposits as well as the linkages between the rhizosphere chemical niche and microbiome remained unknown. In this paper,significant negative correlations between the bacterial alpha diversity and both the disease incidence(r = – 0.832,P = 0.005) and pathogen population(r = – 0.786, P = 0.012)were detected. Moreover, our results showed that the chemical diversity not only predicts bacterial alpha diversity but also can impact on overall microbial community structure(beta diversity) in the rhizosphere.Furthermore, some anti-fungal compounds including heptadecane and hexadecane were identified in the rhizosphere of grafted watermelon. We concluded that grafted watermelon can form a distinct rhizosphere chemical niche and thus recruit microbial communities with high diversity. Furthermore, the diverse bacteria and the antifungal compounds in the rhizosphere can potentially serve as biological and chemical barriers, respectively, to hinder pathogen invasion. These results not only lead us toward broadening the view of disease resistance mechanism of grafting, but also provide clues to control the microbial composition by manipulating the rhizosphere chemical niche.

Kinetically accelerated and high-mass loaded lithium storage enabled by atomic iron embedded carbon nanofibers

Carbonaceous materials represent the dominant choice of materials for anodic lithium storage in many energy storage devices.Nevertheless,the nonpolar carbonaceous materials offer weak adsorption toward Li+that largely denies the high-rate Li+storage.Herein,the atomic Fe sites decorated carbon nanofibers(AICNFs)facilely produced by electrospinning are reported for kinetically accelerated Li+storage.Theoretical calculation reveals that the atomic Fe sites possess coordination unsaturated electronic configuration,enabling suitable bonding energy and facilitated diffusion path of Li+.As a result,the optimal structure displays a high capacitive contribution up to 95.9%at a scan rate of 2.0 mV·s^(−1).In addition,ultrahigh capacity retention of 97%is afforded after 5,000 cycles at a current density of 3 A·g^(−1).Moreover,the interlaced fiber structure enabled by electrospinning benefits structural stability and improved conductivity even at thick electrodes,thus allowing a high areal capacity of 1.76 mAh·cm−2 at a loading of 8 mg·cm−2.Because of these structure and performance merits,the lithium-ion capacitor containing the AICNF-based anode delivers a high energy density and large power density.

Compositional variations of active autotrophic bacteria in paddy soils with elevated CO_(2) and temperature

Global warming is an increasingly serious ecological problem,we examined how the active autotrophic microbes in paddy soils respond to the elevated CO_(2) and temperature.Here we employed stable isotope probing(SIP)to label the active bacteria using the soil samples from a fully factorial Simulated Climate Change(SCC)field experiment where soils were exposed to ambient CO_(2) and temperature,elevated temperature,elevated CO_(2),and both elevated CO_(2) and temperature.Around 28.9% of active OTUs belonged to ammonia-oxidizing bacteria(AOB)and nitrite-oxidizing bacteria(NOB).Nitrosospira taxa was dominant in all soils and 80.4% of carbon-fixing bacteria under elevated temperature were classified as Nitrosomonas nitrosa.While no labeled NOBs were detected when temperature or CO_(2) were elevated independently,diverse NOBs were detected in the ambient conditions.We found that elevated CO_(2) and temperature had contrasting effects on microbial community composition,while relatively small changes were observed when CO_(2) and temperature were elevated simultaneously.Summarily these results suggest that carbon-fixing bacteria can respond positively to elevated CO_(2) concentrations,but when it’s accompanied with increase in the temperature this positive response could be weakened.Multiple abiotic factors thus need to be considered when predicting how microbial communities will respond to multiple climatic factors.

Enzyme/pH-sensitive dendritic polymer-DOX conjugate for cancer treatment

It is in a great demand to design a biodegradable, tumor microenvironment-sensitive drug delivery system to achieve safe and highly efficacious treatment of cancer.Herein, a novel pH/enzyme sensitive dendritic pdi HPMADOX conjugate was designed. di HPMA dendritic copolymer with GFLG segments in the branches which are sensitive to the intracellular enzyme of the tumor was prepared through RAFT polymerization. DOX was attached to dendritic di HPMA polymer through a pH-sensitive hydrazone bond. The dendritic pdi HPMA-DOX conjugate self-assembled into nanoparticles with an ideal spherical shape at a mean size of 103 nm. The DOX attached to the polymeric carrier was released in an acidic environment, and the GFLG linker for synthesizing the dendritic vehicle with a high molecular weight（M_W, 220 kDa） was cleaved to release low MWsegments（〈40 kDa） in the presence of cathepsin B. The dendritic polymeric conjugate was internalized via an endocytic pathway, and then released the anticancer drug, which led to significant cytotoxicity for tumors. The blood circulation time was profoundly prolonged, resulting in high accumulation of DOX into tumors. In vivo anti-tumor experiments with 4 T1 tumor bearing mice demonstrated that the conjugate had a better antitumor efficacy in comparison with free DOX. Additionally, body weight measurements and histological examinations indicated that the conjugate showed low toxicities to normal tissues. This dendritic polymeric drug carrier in a response to intracellular enzyme and acidic pH of tumor tissue or cells holds great promise in tumor-targeted therapy.

The effect of using long-acting octreotide as adjuvant therapy for patients with grade 2 pancreatic neuroendocrine tumors after radical resection

Objective:To investigate the effect of long-acting octreotide as adjuvant therapy in the prevention of tumor recurrence in patients with grade 2 pancreatic neuroendocrine tumors(pNETs)after radical resection.Methods:The postoperative follow-up data of 130 patients with resectable G2 pNET treated in the Changhai Hospital from 2008 to 2018 were retrospectively analyzed:59 patients received long-acting octreotide as adjuvant therapy for 6 to 12 months(Oct group)and 71 patients received active follow-up(control group),both of which began after the radical resection,with the primary observation endpoint of disease-free survival(DFS)and the secondary study endpoint of overall survival.Results:The median age of the patients in the Oct group and control group was 52 and 54 years,respectively.There were 28 male cases(47.5%)and 33 male cases(46.5%)in the 2 groups.The median maximum tumor diameter was 3.5 and 3.0 cm,respectively;lymph node metastasis was positive in 13 cases(22.0%)and 9 cases(12.7%);there was peripancreatic nerve invasion in 11 cases(18.6%)and 6 cases(8.5%).Survival analysis revealed that there were significant differences in 2-year DFS%(98.3%vs 88.7%,P=.0371)and 3-year DFS%(96.6%vs 85.9%,P=.0498)between the Oct group and control group.Long-acting octreotide treatment was found to reduce the risk of 3-year recurrence of G2 pNET after radical resection(HR=0.2,P=.044)with the application of inverse-probability-of-treatment weighted to balance the limited data bias.Conclusion:Using long-acting octreotide as adjuvant therapy for G2 pNET patients after radical surgery may improve the rate of 3y-DFS,but the benefit needs to be confirmed in a well-designed random control clinical trial.

Elastic energy storage technology using spiral spring devices and its applications:A review

Harvesting and storing energy is a key problem in some applications.Elastic energy storage technology has the advantages of wide-sources,simple structural principle,renewability,high effectiveness and environmental-friendliness.This paper elaborates the operational principles and technical properties and summarizes the appli-cability of elastic energy storage technology with spiral springs.Elastic energy storage using spiral spring can realize the balance between energy supply and demand in some applications.Continuous input-spontaneous out-put working style can provide simple energy sources for short-time energy supply,and provide strong moment impact and rapid start,or realize the energy conservation for reciprocating movement.Uniform output working style can realize energy output with uniform speed for timekeeping and load-driving.Random input working style can harvest and store random mechanical energy or convert small torque into a large moment to drive external loads.Finally,this paper proposes new researches and developments of elastic energy storage technology on new materials and structures,mechanical properties and structural dynamics analyses,design and control for new functions.

Survival outcomes of conversion surgery for metastatic pancreatic ductal adenocarcinoma after neoadjuvant therapy

Objective:To evaluate the survival outcomes of patients who underwent conversion surgery for metastatic pancreatic ductal adenocarcinoma(mPDAC)after neoadjuvant therapy(NAT)and to identify potential candidates that may benefit from this treat-ment strategy.Background:The role and eligibility population of conversion surgery for mPDAC remains controversial in the era of NAT.Methods:A consecutive cohort of patients diagnosed with mPDAC and treated with NAT followed by conversion surgery be-tween 2019 and 2021 were confirmed from a prospective database maintained by the Department of Pancreatic Hepatobiliary Surgery of Changhai Hospital.In accordance with residual metastases and technical resectability after NAT,patients were classi-fied as the complete pathological response of metastases(ypM0)resection group,residual metastases(ypM1)resection group,and exploration group.Median overall survival(mOS)was calculated using the Kaplan-Meier method,uni-and multivariable cox regression was performed to identify clinicopathological predictors of OS.Results:A total of 244 patients with mPDAC were identified from the prospective database,with 19(7.8%)patients who un-derwent ypM0 resection,22(9.0%)underwent ypM1 resection,and 23(9.4%)underwent explorative laparotomy.The mOS was 32.6 months for ypM0 resected patients,15.1 months for ypM1 resected patients,and 13.4 months for those who underwent explorative laparotomy(P<.001).Univariable and multivariable Cox regression analyses confirmed that ypM0 resection,normal-ization of preoperative CA19-9 levels,and continued adjuvant therapy were independent prognostic factors of conversion surgery for mPDAC after NAT.Subgroup analyses revealed that oligometastases and continued adjuvant therapy were associated with improved prognosis in the ypM1 resection group.Conclusion:In patients with mPDAC who underwent NAT followed by conversion surgery,the complete pathological response of metastases,normalization of preoperative CA19-9 levels,and continued adjuvant therapy were independent risk factors for prognosis.Patients with residual oligometastases after treatment were expected to prolong survival through resection.These patients may benefit from conversion surgery and should be potential candidates for this treatment strategy.