Integrated Sensing and Secure Communication with XL-MIMO.

This paper studies extremely large-scale multiple-input multiple-output (XL-MIMO)-empowered integrated sensing and secure communication systems, where both the radar targets and the communication user are located within the near-field region of the transmitter. The radar targets, being untrusted entities, have the potential to intercept the confidential messages intended for the communication user. In this context, we investigate the near-field beam-focusing design, aiming to maximize the achievable secrecy rate for the communication user while satisfying the transmit beampattern gain requirements for the radar targets. We address the corresponding globally optimal non-convex optimization problem by employing a semidefinite relaxation-based two-stage procedure. Additionally, we provide a sub-optimal solution to reduce complexity. Numerical results demonstrate that beam focusing enables the attainment of a positive secrecy rate, even when the radar targets and communication user align along the same angle direction.

University MOOC should be added with farmer interested sections and provide individualized service to adapt to farmer training.

Vegetables represent an important agricultural industry in China. New farmers and new technologies for vegetable production have emerged in recent years, which makes farmer training very necessary. On the other hand, massive open online courses (MOOCs) are currently widely used in universities. The purpose of this study is to investigate the importance of different sections of a university MOOC focused on olericulture to farmers with different demographic characteristics and provide a basis to improve university MOOCs for farmer training. The survey results suggest that the age, education level, gender, farmer scale, facility type and profit of farmer learners are important factors determining evaluations of the importance of different MOOC sections, indicating that services customized to different farmer populations are necessary. Among different sections of MOOC "Olericulture", farmers with younger age, higher education, larger farm, more advanced facility and more profit were more interesting in sections include cultural, social and theoretical knowledge, and less interesting in practical skill sections. Based on the survey, eight new sections including one marketing subsection (new agricultural supplies and market news), one social subsection (laws and regulations), two practical subsections (practice videos, photos and videos from other farms), and three comprehensive subsections (discussion of practical issues, mechanization, and smart olericulture) were added to the original MOOC, and the results indicate that this improvement is efficient in enhancing the importance evaluations and profits of all farmer learners, especially among those with high education levels.

Genome-Wide Identification and Expression Patterns of Cucumber Invertases and Their Inhibitor Genes.

Invertases and their inhibitors play important roles in sucrose metabolism, growth and development, signal transduction, and biotic and abiotic stress tolerance in many plant species. However, in cucumber, both the gene members and functions of invertase and its inhibitor families remain largely unclear. In this study, in comparison with the orthologues of Citrullus lanatus (watermelon), Cucumis melo (melon), and Arabidopsis thaliana (Arabidopsis), 12 invertase genes and 12 invertase inhibitor genes were identified from the genome of Cucumis sativus (cucumber). Among them, the 12 invertase genes were classified as 4 cell wall invertases, 6 cytoplasmic invertases, and 2 vacuolar invertases. Most invertase genes were conserved in cucumber, melon, and watermelon, with several duplicate genes in melon and watermelon. Transcriptome analysis distinguished these genes into various expression patterns, which included genes CsaV3_2G025540 and CsaV3_2G007220, which were significantly expressed in different tissues, organs, and development stages, and genes CsaV3_7G034730 and CsaV3_5G005910, which might be involved in biotic and abiotic stress. Six genes were further validated in cucumber based on quantitative real-time PCR (qRT-PCR), and three of them showed consistent expression patterns as revealed in the transcriptome. These results provide important information for further studies on the physiological functions of cucumber invertases (CSINVs) and their inhibitors (CSINHs).

Periosteum-derived skeletal stem cells encapsulated in platelet-rich plasma enhance the repair of bone defect.

BACKGROUND: Spontaneous restoration of large bone defects remains a challenge under infections, tumors, and crushing conditions. Current stem cell-based therapies for treating bone defects need improvement, because the used stem cells are isolated by a traditional protocol, which is based on their properties of in-vitro plastic adherence and fibroblastic colony formation. The stem cells isolated by the traditional protocol belong to a multicellular type mixture, individual cells vary in proliferative and osteogenic potential. Thus, developing a protocol capable of isolating stem cell subset with higher purity is required and urgent. AIM: This study aimed to sort a subpopulation of stem cells from periosteum using flow cytometry (named as FC-PSCs), and evaluate the proliferative and osteogenic capacity of FC-PSCs in-vitro, and then establish a new stem cell-based therapies for treating bone defects by delivering the FC-PSCs within platelet-rich plasma (PRP). METHODS: Mouse periosteum was used to sort FC-PSCs using flow cytometry with CD45-TER119-TIE2-ITGAV+CD90 + 6C3-CD105- markers, or isolate periosteum-derived stem cells with the traditional protocol (TP-PSCs) as control. After evaluating the FC-PSCs proliferation and osteogenic differentiation in-vitro as well as the promotive efficacy of platelet-rich plasma (PRP) on FC-PSCs proliferation and osteogenic differentiation, the FC-PSCs were delivered into the femoral epiphysis bone defect site of a mouse model by platelet-rich plasma (PRP). At postoperative 14 or 28 days, these mice were euthanized for harvest the femur specimens for micro-CT, histological evaluation. RESULTS: In-vitro results determined that the FC-PSCs showed more capacity for proliferation and osteogenic differentiation compared with the TP-PSCs. In addition, in-vitro results showed the promotive efficacy of PRP on FC-PSCs proliferation and osteogenic differentiation. In-vivo results showed that the FC-PSCs delivered by PRP was able to facilitate the repair of bone defects by stimulating new bone formation and remodeling. CONCLUSION: FC-PSCs delivered by PRP enhance the repair of bone defects by stimulating new bone formation and remodeling.

Cucumber STACHYOSE SYNTHASE is regulated by its cis-antisense RNA asCsSTS to balance source-sink carbon partitioning.

Photosynthate partitioning between source and sink is a key determinant of crop yield. In contrast to sucrose-transporting plants, cucumber (Cucumis sativus) plants mainly transport stachyose and stachyose synthase (CsSTS) synthesizes stachyose in the vasculature for loading. Therefore, CsSTS is considered a key regulator of carbon partitioning. We found that CsSTS expression and CsSTS enzyme activity were upregulated in the vasculature and downregulated in mesophyll tissues at fruiting. In situ hybridization and tissue enrichment experiments revealed that a cis-natural antisense noncoding transcript of CsSTS, named asCsSTS, is mainly expressed in mesophyll tissues. In vitro overexpression (OE), RNA interference (RNAi), and dual luciferase reporter experiments indicated that CsSTSs are negatively regulated by asCsSTS. Fluorescence in situ hybridization revealed that asCsSTS transcript localized in leaf cytoplasm, indicating that the regulation of CsSTS by asCsSTS is a posttranscriptional process. Further investigation revealed that this regulation occurred by reducing CsSTS transcript stability through a DICER-like protein-mediated pathway. Chemically induced OE and RNAi of asCsSTS led to promotion or inhibition, respectively, of assimilate export from leaves and altered fruit growth rates. Our results suggest that the regulation of CsSTSs between the mesophyll and vasculature reduces sugar storage in mesophyll tissue and promotes assimilate export from the leaf when the plant carries fruit.

Effects of Exogenous α-Naphthaleneacetic Acid and 24-Epibrassinolide on Fruit Size and Assimilate Metabolism-Related Sugars and Enzyme Activities in Giant Pumpkin.

Size is the most important quality attribute of giant pumpkin fruit. Different concentrations and application frequencies of α-naphthaleneacetic acid (NAA) and 24-epibrassinolide (EBR) were sprayed on the leaves and fruits of giant pumpkin at different growth stages to determine their effects and the mechanism responsible for fruit size increase. NAA+EBR application improved source strength, and further analysis indicated that NAA+EBR markedly boosted net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr) and the expression level and activity of galactitol synthetase (GolS), raffinose synthetase (RS), and stachyose synthetase (STS), resulting in an increase in the synthesis of photoassimilate, especially stachyose. Concomitantly, NAA+EBR spray increased stachyose and sucrose contents throughout pumpkin fruit growth and the concentrations of glucose and fructose at 0 and 20 days post-anthesis (DPA) in peduncle phloem sap, implying that such treatment improved the efficiency of assimilate transport from the peduncle to the fruit. Furthermore, it improved the expression and activity of alkaline α-galactosidase (AGA), facilitating assimilate unloading, providing carbon skeletons and energy for fruit growth, and increasing fruit weight by more than 44.1%. Therefore, exogenous NAA and EBR increased source capacity, transportation efficiency, and sink strength, overall promoting the synthesis and distribution of photoassimilate, ultimately increasing fruit size.

Whole-genome resequencing identified QTLs, candidate genes and Kompetitive Allele-Specific PCR markers associated with the large fruit of Atlantic Giant (Cucurbita maxima).

Atlantic Giant (AG) pumpkin (Cucurbita maxima) produces the world's largest fruit. Elucidating the molecular mechanism of AG fruit formation is of scientific and practical importance. In this research, genome-wide resequencing of an F2 population produced by a cross between AG and its small-fruit ancestor Hubbard was used to identify quantitative trait loci (QTLs) and candidate genes. Transgressive segregation of fruit size-related traits was observed in the F2 population, suggesting that fruit size was a quantitative trait controlled by multiple genes. A genetic map with an average physical distance of 154 kb per marker was constructed, and 13 QTLs related to fruit size were identified using bin-map construction. RNA sequencing analysis revealed that pathways associated with assimilate accumulation into the fruit, including carbohydrate metabolism, were significantly enriched in differentially expressed genes. According to the predicted impact of mutation on the biological function of certain proteins, 13 genes were selected as candidate genes associated with fruit size, among which two phytohormone-related genes, CmaCh17G011340 (a flavin-containing monooxygenase) and CmaCh04G029660 (a leucine-rich repeat protein kinase) were chosen for further investigation. Finally, one insertion-deletion (inDel) and three single nucleotide polymorphisms (SNPs) were successfully transformed to Kompetitive Allele-Specific PCR (KASP) markers. The novel QTLs and candidate genes identified provide insights into the genetic mechanism of large fruit formation of AG, and the genetic map and tightly linked KASP markers developed in this study can be employed for marker-assisted breeding to alter fruit size of C. maxima.

Differential responses of polysaccharides and antioxidant enzymes in alleviating cadmium toxicity of tuber traditional Chinese medicinal materials.

Polygonatum cyrtonema Hua (PC) and Bletilla striata (BS) are widely used and planted as tuber traditional Chinese medicinal materials (TCMMs). Cadmium (Cd) is one of the major causes of soil pollution and challenge to the quality and safety of TCMMs. Understanding the absorption and distribution of Cd is important for addressing the risks posed by its residues. As a result, the higher Cd translocation factor (TF) results in the lower Cd bioconcentration factor (BCF) in the PC tuber than that of BS attributed to a lower Cd concentration in the PC tuber, which guaranteed its safe utilization and edible safety under 1 mg·kg-1 Cd soil. Cd stress overall activated peroxidase (POD), catalase (CAT), and water-extractable polysaccharides in PC (PCP1) to exhibit better antioxidation, while the superoxide dismutase (SOD) in BS increased by approximately 206-277% to alleviate more severe oxidative damage. Particularly, Cd induced an increase in PCP1 higher than that of water-extractable polysaccharides of BS (BSP1) by approximately 335% to 1351%. PC exhibited effective strategies for alleviating Cd toxicity, including transferring Cd to nonmedicinal parts, increasing polysaccharides, and synergistically activating the enzymatic antioxidant system. This study expands the application for the safe utilization of low-Cd contaminated soil and provides novel insights for tuber TCMMs to alleviate Cd toxicity.

Galactinol synthase 1 improves cucumber performance under cold stress by enhancing assimilate translocation.

Cucumber (Cucumis sativus L.) predominately translocates raffinose family oligosaccharides (RFOs) in the phloem and accumulates RFOs in leaves. Galactinol synthase (GolS) catalyzes the critical step of RFO biosynthesis, and determining the functional diversity of multiple GolS isoforms in cucumber is of scientific significance. In this study, we found that all four isoforms of CsGolS in the cucumber genome were upregulated by different abiotic stresses. ß-glucuronidase staining and tissue separation experiments suggested that CsGolS1 is expressed in vascular tissues, whereas the other three CsGolSs are located in mesophyll cells. Further investigation indicates that CsGolS1 plays double roles in both assimilate loading and stress response in minor veins, which could increase the RFO concentration in the phloem sap and then improve assimilate transport under adverse conditions. Cold-induced minor vein-specific overexpression of CsGolS1 enhanced the assimilate translocation efficiency and accelerated the growth rates of sink leaves, fruits and whole plants under cold stress. Finally, our results demonstrate a previously unknown response to adverse environments and provide a potential biotechnological strategy to improve the stress resistance of cucumber.

CsAGA1 and CsAGA2 Mediate RFO Hydrolysis in Partially Distinct Manner in Cucumber Fruits.

A Raffinose family oligosaccharides (RFOs) is one of the major translocated sugars in the vascular bundle of cucumber, but little RFOs can be detected in fruits. Alpha-galactosidases (α-Gals) catalyze the first catabolism step of RFOs. Six α-Gal genes exist in a cucumber genome, but their spatial functions in fruits remain unclear. Here, we found that RFOs were highly accumulated in vascular tissues. In phloem sap, the stachyose and raffinose content was gradually decreased, whereas the content of sucrose, glucose and fructose was increased from pedicel to fruit top. Three alkaline forms instead of acid forms of α-Gals were preferentially expressed in fruit vascular tissues and alkaline forms have stronger RFO-hydrolysing activity than acid forms. By inducible gene silencing of three alkaline forms of α-Gals, stachyose was highly accumulated in RNAi-CsAGA2 plants, while raffinose and stachyose were highly accumulated in RNAi-CsAGA1 plants. The content of sucrose, glucose and fructose was decreased in both RNAi-CsAGA1 and RNAi-CsAGA2 plants after ß-estradiol treatment. In addition, the fresh- and dry-weight of fruits were significantly decreased in RNAi-CsAGA1 and RNAi-CsAGA2 plants. In cucurbitaceous plants, the non-sweet motif within the promoter of ClAGA2 is widely distributed in the promoter of its homologous genes. Taken together, we found RFOs hydrolysis occurred in the vascular tissues of fruits. CsAGA1 and CsAGA2 played key but partly distinct roles in the hydrolysis of RFOs.

Antioxidant system response, mineral element uptake and safe utilization of Polygonatum sibiricum in cadmium-contaminated soil.

Chinese herbal medicine is widely cultivated in Southwest China, where the soil cadmium (Cd) contamination of farmland is more serious than that in China as a whole. In this study, Polygonatum sibiricum was exposed to Cd at concentrations of e-1, e0, e2, and e4 mg/kg for 30, 60, and 90 days, and the physiological stress responses, Cd and mineral element uptake, antioxidant enzyme activities, and content changes of pharmaceutical ingredients (polysaccharides) were analyzed to decipher the feasibility of safe utilization in Cd-contaminated soil. The results show that the activity of antioxidant enzymes (SOD and CAT) in the aboveground part was always higher than that in the underground part. The underground part of Polygonatum sibiricum mobilizes nonenzymatic systems to facilitate the synthesis of polysaccharides (PCP1, PCP2) with antioxidant properties to cope with Cd stress. Mineral elements (P, K, Ca, Mg, Fe, Cu, and Zn) significantly (p < 0.05) changed after 90 d of cultivation. In particular, the changes in the iron and zinc content were significantly correlated (p < 0.05) with the activities of SOD and POD. Soil Cd at e0 mg/kg can guarantee the safe production and utilization of Polygonatum sibiricum, and the stimulation of Cd promotes polysaccharide synthesis and biomass growth.

Characteristics and expression patterns of six α-galactosidases in cucumber (Cucumis sativus L.).

Six putative α-galactosidase genes (α-Gals), three acid forms (CsGAL1, CsGAL2, CsGAL3) and three alkaline forms (CsAGA1, CsAGA2, CsAGAL3), were found in the cucumber genome. It is interesting to know the expression pattern and possible function of these α-Gals in the cucumber plant since it is a stachyose-translocating species. In this study, full-length cDNAs of six α-Gals were cloned and heterologously expressed. The result showed that all recombinant proteins revealed acid or alkaline α-Gal activities with different substrate specificities and pH or temperature responding curves, indicating their distinct roles in cucumber plants. Phylogenetic analysis of collected α-Gal amino acid sequences from different plants indicated that the ancestor of both acid and alkaline α-Gals existed before monocots and dicots separated. Generally, six α-Gal genes are universally expressed in different cucumber organs. CsGAL2 highly expressed in fasting-growing leaves, fruits and germinating seeds; CsGAL3 mainly distributes in vacuoles and significantly expressed in cucumber fruits, senescent leaves and seeds during late stage germination; The expression of CsAGA1 increased from leaf 1 to leaf 3 (sink leaves) and then declined from leaf 4 to leaf 7 (source leaves), and this isoform also highly expressed in male flowers and germinating seeds at early stage; CsAGA2 significantly expressed in cucumber leaves and female flowers; CsAGA3 is localized in plastids and also actively expressed in senescent leaves and germinating seeds; The role of CsGAL1 in cucumber plants is now unclear since its expression was relatively low in all organs. According to their expression patterns, subcellular localizations and previously reported functions of these isoforms in other plants, combining the data of soluble sugars contents in different tissues, the possible functions of these α-Gals were discussed.

Alternative polyadenylation of the stacyose synthase gene mediates source-sink regulation in cucumber.

Alternative polyadenylation (APA) is a pervasive mechanism for gene regulation in eukaryotes. Stachyose is the main assimilate translocated in the cucumber phloem. Stachyose synthase (CsSTS) catalyzes the last step of stachyose biosynthesis in cucumber leaves and plays a key role in the regulation of assimilate partitioning between source and sink. In this study, three CsSTS mRNAs with the same open reading frame and the 5`untranslated region (UTR), but differing in their 3`UTRs, named CsSTS1 (short), CsSTS2 (medium), and CsSTS3 (long), were identified. Southern blot and sequence analysis of the cucumber genome confirmed that these transcripts are regulated through APA from a single gene. No significant difference of in vitro translation efficiency was found among three mRNAs. However, the relative stabilities of three transcripts varied among different tissues and different leaf development stages of cucumber. CsSTS1 expression in cucumber calli was up-regulated by the raffinose (substrate of CsSTS) and down-regulated by stachyose (product of CsSTS), respectively. In cucumber plants, all three isoforms have considerable expression in non-fruit node leaves. However, in fruit-carrying node leaves, the expression of CsSTS2 and CsSTS3 was severely inhibited and only CsSTS1 was highly expressed, indicating fruit setting has a remarkable effect on the relative expression level of three transcripts. This "fruit setting" effect could be observed until at least 36 h after the fruit was removed from the node. Our results suggest that abundant expression of CsSTS1 is beneficial for stachyose loading in source leaves, and APA is a delicate mechanism for CsSTS to regulate cucumber source-sink balance.

Metabolic responses and their correlations with phytochelatins in Amaranthus hypochondriacus under cadmium stress.

Phytochelatins (PCs) play a vital role in the tolerance and enrichment of cadmium (Cd) in higher plants by chelating with Cd2+. The aim of this study was to perform a full-scale metabolomics analysis of metabolic responses highly correlated with PCs generation. These metabolites and metabolic pathways were expected to promote PCs generation and further optimize Cd absorption in plants. In the current study, Amaranthus hypochondriacus, a potential species for phytoremediation, was first adopted to investigate physiological responses to Cd stress via LCMS/MS-based metabolomics and the HPLC based determination of thiol compounds. The results showed that the leaves of A. hypochondriacus under high Cd stress accumulated 40 times the amount of Cd compared to the leaves of the plants not under Cd stress and had an increased content of three types of PCs. Metabolomics qualitatively identified 12084 substances in total, among which 41 were significantly different metabolites (SDMs) between the two groups and involved in 7 metabolic pathways. Among the SDMs, 12 metabolites were highly linearly correlated with PCs involved in three pathways (Val, Leu and Ile biosynthesis; Ala, Asp and Glu metabolism; and Arg and Pro metabolism). These results provide an innovative method to promote PCs synthesis for the restoration of Cd-contaminated-soil.

mTOR signaling in osteosarcoma: Oncogenesis and therapeutic aspects (Review).

The mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase that belongs to the phosphoinositide-3-kinase (PI3K)-related kinase family. Oncogenic activation of mTOR signaling significantly contributes to the progression of different types of cancers including osteosarcoma (OS; the most common primary malignant tumor of bone). In the present study, we review the association of the mTOR signaling pathway with OS, and the possible effective treatment strategies by targeting this pathway. In the metastatic behavior of OS, one of the most common actionable aberrations was found in the PI3K/Akt/mTOR pathway. Upon phosphorylation, activated mTOR contributes to OS cellular transformation and poor cancer prognosis via downstream effectors such as S6K1, 4EBP1 and eIF4E, which are overexpressed in OS. Targeting the mTOR complex is a significant approach in cancer therapeutic research, and of course, rapamycin is the primary inhibitor of mTOR. Various other chemotherapeutic molecules have also shown potential activity against mTOR. As mTOR is a new promising oncological target and blockade of the mTOR pathway with selective inhibitors has significant potential in OS therapeutic research, the development of the optimal dose, regimen and a rationale for the use of mTOR inhibitors in combination with other anticancer agents may provide a successful treatment strategy for OS.