Hedysarumqilianshanense sp. nov. (Fabaceae, Hedysareae), a new species from the Qilianshan Mountains in Gansu, China.

Hedysarumqilianshanensesp. nov. (Fabaceae, Hedysareae) is described and illustrated from the Qilianshan Mountains in Gansu, China. This new species is similar to H.przewalskii, but can be distinguished by its corolla being light purple to purple, standard 15-19 mm long, wings 14-16 mm long, keels 16-19 mm long, and the ovary and legume being glabrous. The new species can be easily distinguished from H.neglectum Ledeb. by its bract being shorter than the pedicel, and the ovary and legume being glabrous. Phylogenetic tree based on the nuclear ITS and ETS sequences shows that H.qilianshanense is sister to H.przewalskii, while the tree based on the plastid psbA-trnH, trnC-petN, trnL-F, trnS-G and petN-psbM sequences shows H.qilianshanense as sister to a clade consisting of H.hedysaroides, H.inundatum, H.americanum and H.neglectum. The new species is a diploid with the chromosome number 2n = 14. Based on morphological, phylogenetic and karyotypic evidence, the new species may originate from an ancient homoploid hybrid speciation event.

Tetrahedral Occupied V Ions Enabling Reversible Three-Electron Redox of Cr3+ /Cr6+ in Layered Cathode Materials for Potassium-Ion Batteries.

Reversible three-electron redox of Cr3+ /Cr6+ in layered cathode materials for rechargeable batteries is very attractive in layered cathode materials, which leads to high capacity and energy density for rechargeable batteries. However, the poor reversibility and Cr-ion migration make it very challenging. In this work, by introducing V ions into tetrahedral sites of layer-structured NaCrO2 , reversible three-electron redox of Cr3+ /Cr6+ is realized successfully in NaCr0.92 V0.05 O2 (NCV05) cathode for potassium-ion batteries with a cut-off voltage of 4.0 V. V ions can weaken the attraction of Cr to electrons, leading to enhanced valence change of Cr ions. On the other hand, V in tetrahedral sites can facilitate the reversible migration of Cr between octahedral and tetrahedral sites via coulombic repulsion to realize the reversible redox between Cr3+ and Cr6+ during charge and discharge processes. In addition, V ions can inhibit the phase transition from O3 phase to O'3 phase during the charge process by adjusting the crystal lattices. As a result, the NaCr0.92 V0.05 O2 cathode exhibits a high reversible capacity of 130 mAh g-1 with promising cycle stability and rate capability. The strategy opens new opportunity for developing high-capacity cathode materials for potassium-ion batteries.

Characterization of the complete chloroplast genome of Gypsophila huashanensis Y. W. Tsui & D. Q. Lu, an endemic herb species in China.

Gypsophila huashanensis Y. W. Tsui & D. Q. Lu (Caryophyllaceae) is an endemic herb species to the Qinling Mountains in China. In this study, we characterized its whole plastid genome using the Illumina sequencing platform. The complete plastid genome of G. huashanensis is 152,457 bp in length, including a large single-copy DNA region of 83,476 bp, a small single-copy DNA region of 17,345 bp, and a pair of inverted repeat DNA sequences of 25,818 bp. The genome contains 130 genes comprising 85 protein-coding genes, 37 tRNA genes, and eight rRNA genes. Evolutionary analysis showed that the non-coding regions of Caryophyllaceae exhibit a higher level of divergence than the exon regions. Gene site selection analysis suggested that 11 coding protein genes (accD, atpF, ndhA, ndhB, petB, petD, rpoCl, rpoC2, rps16, ycfl, and ycf2) have some sites under protein sequence evolution. Phylogenetic analysis showed that G. huashanensis is most closely related to the congeneric species G. oldhamiana. These results are very useful for studying phylogenetic evolution and species divergence in the family Caryophyllaceae.

Stacking Order Induced Anion Redox Regulation for Layer-Structured Na0.75 Li0.2 Mn0.7 Cu0.1 O2 Cathode Materials.

Stacking order plays a key role in defining the electrochemical behavior and structural stability of layer-structured cathode materials. However, the detailed effects of stacking order on anionic redox in layer-structured cathode materials have not been investigated specifically and are still unrevealed. Herein, two layered cathodes with the same chemical formula but different stacking orders: P2-Na0.75 Li0.2 Mn0.7 Cu0.1 O2 (P2-LMC) and P3-Na0.75 Li0.2 Mn0.7 Cu0.1 O2 (P3-LMC) are compared. It is found that P3 stacking order is beneficial to improve the oxygen redox reversibility compared with P2 stacking order. By using synchrotron hard and soft X-ray absorption spectroscopies, three redox couples of Cu2+ /Cu3+ , Mn3.5+ /Mn4+ , and O2- /O- are revealed to contribute charge compensation in P3 structure simultaneously, and two redox couples of Cu2+ /Cu3+ and O2- /O- are more reversible than those in P2-LMC due to the higher electronic densities in Cu 3d and O 2p orbitals in P3-LMC. In situ X-ray diffraction reveals that P3-LMC exhibits higher structural reversibility during charge and discharge than P2-LMC, even at 5C rate. As a result, P3-LMC delivers a high reversible capacity of 190.3 mAh g-1 and capacity retention of 125.7 mAh g-1 over 100 cycles. These findings provide new insight into oxygen-redox-involved layered cathode materials for SIBs.

Transition Metal Vacancy in Layered Cathode Materials for Sodium-Ion Batteries.

Anionic redox has been considered as a promising strategy to break the capacity limitation of cathode materials that solely relies on the intrinsic cationic redox in secondary batteries. Vacancy, as a kind of defect, can be introduced into transition metal layer to trigger oxygen redox, thus enhancing the energy density of layer-structured cathode materials for sodium-ion batteries. Herein, the formation process, recent progress in working mechanisms of triggering oxygen redox, as well as advanced characterization techniques for transition metal (TM) vacancy were overviewed and discussed. Strategies applied to stabilize the vacancy contained structures and harness the reversible oxygen redox were summarized. Furthermore, the challenges and prospects for further understanding TM vacancy were particularly emphasized.

Analysis of clinicopathological characteristics, therapeutic strategy and prognosis of 501 patients with gastric neuroendocrine neoplasms attending a single center / 中华胃肠外科杂志

Objective: To explore the clinicopathological features, treatment strategy and to analysis of prognosis-related risk factors of gastric neuroendocrine neoplasms(G-NEN). Methods: In this study, a retrospective observational study method was used to collect the clinicopathological data of patients diagnosed with G-NEN by pathological examination in the First Medical Center of PLA General Hospital from January 2000 to December 2021. The basic information of the patients, tumor pathological characteristics, and treatment methods were entered, and the treatment information and survival data after discharge were followed up and recorded. The Kaplan-Meier method was used to construct survival curves, and the log-rank test to analyze the differences in survival between groups. Cox Regression model analysis of risk factors affecting the prognosis of G-NEN patients. Results: Among the 501 cases confirmed as G-NEN, 355 were male and 146 were female, and their median age was 59 years. The cohort comprised 130 patients (25.9%) of neuroendocrine tumor (NET) G1, 54 (10.8%) of NET G2, 225 (42.9%) of neuroendocrine carcinoma (NEC), and 102 cases (20.4%) of mixed neuroendocrine-non-neuroendocrine(MiNEN). Patients NET G1 and NET G2 were mainly treated by endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR). The main treatment for patients with NEC/MiNEN was the same as that for gastric malignancies, namely radical gastrectomy+lymph node dissection supplemented with postoperative chemotherapy. There were significant differences in sex, age, maximum tumor diameter, tumor morphology, tumor numbers, tumor location, depth of invasion, lymph node metastasis, distant metastasis, TNM staging and expression of immunohistological markers Syn and CgA among NET, NEC, and MiNEN patients (all P<0.05). Further for NET subgroup analysis, there were significant differences between NET G1 and NET G2 in the maximum tumor diameter, tumor shape and depth of invasion(all P<0.05). 490 patients (490/501, 97.8%) were followed up with a median of 31.2 months. 163 patients had a death during follow-up (NET G1 2, NET G2 1, NEC 114, MiNEN 46). For NET G1, NET G2, NEC and MiNEN patients,the 1-year overall survival rates were 100%, 100%, 80.1% and 86.2%, respectively; the 3-year survival rates were 98.9%, 100%, 43.5% and 55.1%, respectively. The differences were statistically significant (P<0.001). Univariate analysis showed that gender, age, smoking history, alcohol history, tumor pathological grade, tumor morphology, tumor location, tumor size, lymph node metastasis, distant metastasis, and TNM stage were associated with the prognosis of G-NEN patients (all P<0.05). Multivariate analysis showed that age ≥60 years, pathological grade of NEC and MiNEN, distant metastasis, and TNM stage III-IV were independent factors influencing the survival of G-NEN patients (all P<0.05). 63 cases were stage IV at initial diagnosis. 32 of these were treated with surgery and 31 with palliative chemotherapy. Stage IV subgroup analysis showed that the 1-year survival rates were 68.1% and 46.2% in the surgical treatment and palliative chemotherapy groups, respectively, and the 3-year survival rates were 20.9% and 10.3%, respectively; the differences were statistically significant (P=0.016). Conclusions: G-NEN is a heterogeneous group of tumors. Different pathological grades of G-NEN have different clinicopathological features and prognosis. Factors such as age ≥ 60 years old, pathological grade of NEC/MiNEN, distant metastasis, stage III, IV mostly indicate poor prognosis of patients. Therefore, we should improve the ability of early diagnosis and treatment, and pay more attention to patients with advanced age and NEC/MiNEN. Although this study concluded that surgery improves the prognosis of advanced patients more than palliative chemotherapy, the value of surgical treatment for patients with stage IV G-NEN remains controversial.

Research progress of polymer self-healing mechanism and its application in biomedicine / 药学学报

Polymer self-healing is mainly based on the molecular structure and interaction of polymers, and some need external stimulation, such as light, heat, pH, etc. In recent years, many studies have found that the self-healing properties of polymers can prolong the life of materials, while maintaining the mechanical properties of polymers after healing. According to the different action modes of polymer materials, it can be divided into autonomous self-healing and non-autonomous self-healing. Among them, autonomous self-healing mainly works through reversible covalent bonds (Schiff base bond, Diels-Alder reaction, hydrazide bond), reversible non-covalent bonds (hydrogen bond, metal-ligand coordination bond, electrostatic interaction, π-π stacking interaction, hydrophobic interaction) and a combination of the two interactions. Drug carriers with unique self-healing properties play an important role in the encapsulation and stable release of biomacromolecules. In this review, the self-healing mechanism of polymers and their applications in the field of biomedicine were briefly summarized and discussed.

Establishment and validation of a nomogram for predicting prognosis of gastric neuroendocrine neoplasms based on data from 490 cases in a single center / 南方医科大学学报

OBJECTIVE@#To develop and validate a nomogram for predicting outcomes of patients with gastric neuroendocrine neoplasms (G-NENs).@*METHODS@#We retrospectively collected the clinical data from 490 patients with the diagnosis of G-NEN at our medical center from 2000 to 2021. Log-rank test was used to analyze the overall survival (OS) of the patients. The independent risk factors affecting the prognosis of G-NEN were identified by Cox regression analysis to construct the prognostic nomogram, whose performance was evaluated using the C-index, receiver-operating characteristic (ROC) curve, area under the ROC curve (AUC), calibration curve, DCA, and AUDC.@*RESULTS@#Among the 490 G-NEN patients (mean age of 58.6±10.92 years, including 346 male and 144 female patients), 130 (26.5%) had NET G1, 54 (11.0%) had NET G2, 206 (42.0%) had NEC, and 100 (20.5%) had MiNEN. None of the patients had NET G3. The numbers of patients in stage Ⅰ-Ⅳ were 222 (45.3%), 75 (15.3%), 130 (26.5%), and 63 (12.9%), respectively. Univariate and multivariate analyses identified age, pathological grade, tumor location, depth of invasion, lymph node metastasis, distant metastasis, and F-NLR as independent risk factors affecting the survival of the patients (P < 0.05). The C-index of the prognostic nomogram was 0.829 (95% CI: 0.800-0.858), and its AUC for predicting 1-, 3- and 5-year OS were 0.883, 0.895 and 0.944, respectively. The calibration curve confirmed a good consistency between the model prediction results and the actual observations. For predicting 1-year, 3-year and 5-year OS, the TNM staging system and the nomogram had AUC of 0.033 vs 0.0218, 0.191 vs 0.148, and 0.248 vs 0.197, respectively, suggesting higher net benefit and better clinical utility of the nomogram.@*CONCLUSION@#The prognostic nomogram established in this study has good predictive performance and clinical value to facilitate prognostic evaluation of individual patients with G-NEN.

Pilot-Scale Synthesis Sodium Iron Fluorophosphate Cathode with High Tap Density for a Sodium Pouch Cell.

Sodium-ion batteries (SIBs) have attracted wide interest for energy storage because of the sufficient sodium element reserve on the earth; however, the electrochemical performance of SIBs cannot achieve the requirements so far, especially, the limitation of cathode materials. Here, a kilogram-scale route to synthesize Na2 FePO4 F/carbon/multi-walled carbon nanotubes microspheres (NFPF@C@MCNTs) composite with a high tap density of 1.2 g cm-3 is reported. The NFPF@C@MCNTs cathode exhibits a reversible specific capacity of 118.4 mAh g-1 at 0.1 C. Even under 5 C with high mass loading (10 mg cm-2 ), the specific capacity still maintains at 56.4 mAh g-1 with a capacity retention rate of 97% after 700 cycles. In addition, a hard carbon||NFPF@C@MCNTs pouch cell is assembled and tested, which exhibits a volumetric energy density of 325 Wh L-1 and gravimetrical energy density of 210 Wh kg-1 (base on electrode massing), and it provides more than 200 cycles with a capacity retention rate of 92%. Furthermore, the pouch cell can operate in an all-climate environment ranging from -40 to 80 °C. These results demonstrate that the NFPF@C@MCNTs microspheres are a promising candidate cathode for SIBs and facilitate its practical application in sodium cells.

Efficacy and Safety of Bushen Huoxue Formula in Patients with Discogenic Low-Back Pain: A Double-Blind, Randomized, Placebo-Controlled Trial.

OBJECTIVE: To assess the efficacy and safety of Bushen Huoxue Formula (BSHXF) for the treatment of discogenic low-back pain (DLBP). METHODS: This was a parallel, double-blind, randomized, clinical trial performed between May 2019 and June 2020. Seventy patients were assigned by computerized random number table to the treatment group (lumbar traction and BSHXF, 35 cases) or the control group (lumbar traction and placebo, 35 cases). The patients received intervention for 3 weeks. Assessment was conducted before treatment and at week 1, 2, 3 during treatment. Primary outcome was the self-reported score of Oswestry Disability Index (ODI). Secondary outcomes included Visual Analog Scale (VAS), clinical efficacy rate by minimal clinically important difference (MCID) as well as lumbar tenderness, muscle tone and lumbar spine mobility. Adverse reactions were recorded. Follow-up was performed at 1 and 3 months after the end of treatment. RESULTS: In the treatment group, ODI score was significantly decreased compared with baseline (P<0.05) and the control group at 2- and 3- week treatment. Similarly, VAS score decreased compared with the baseline (P<0.05) and was lower than that in the control group at 2- and 3- week treatment (P<0.05). The clinical efficacy rate of the treatment group was higher than that of the control group after treatment [32.35% (11/34) vs. 3.13% (1/32), P<0.05). Moreover, the tenderness, and muscle tone, as well as the back extension and left flexion in lumbar spine mobility in the treatment group at 3-week treatment were significantly improved compared with the control group (P<0.05). Follow-up showed that at 1-month after treatment, the treatment group had better outcomes than the control group with regard to a total score of ODI and VAS scores, as well as clinical efficacy rate (all P<0.05). Moreover, VAS score was still significantly lower than the control group at 3-month follow-up (P<0.05). No adverse reactions were reported during the study. CONCLUSION: BSXHF combined with lumbar traction can significantly improve the clinical symptoms including pain intensity, functionality, muscle tone, and lumbar spine mobility in DLBP patients. (Registration No. ChiCTR1900027777).

[Research progress in mechanism of Chinese herbal compounds and monomers in delaying lumbar intervertebral disc degeneration].

Traditional Chinese medicine has unique advantages in the treatment of degenerative bone and joint diseases, and its widely used in clinical practice. In recent years, many scholars have conducted a large number of basic studies on the delay of intervertebral disc degeneration by herbal compound and monomeric components from different perspectives. In order to further elucidate its mechanism of action, this paper summarizes the in vivo and in vitro experimental studies conducted at the level of both herbal compound and single components, respectively, in order to provide references for the basic research on the treatment of lumbar intervertebral disc degeneration by Chinese medicine. A summary shows that commonly used herbal compound prescriptions include both classical prescriptions such as Duhuo Jisheng Decoction, as well as clinical experience prescriptions such as Yiqi Huoxue Recipe. Angelicae Sinensis Radix, Chuanxiong Rhizoma, Rehmanniae Radix Praeparata, Achyranthis Bidentatae Radix, and Eucommiae Cortex were used most frequently. Tonic for deficiency and blood stasis activators were used most frequently. The most utilized monomeric components include icariin, ginsenoside Re, salvianolic acid B and aucubin. The main molecular mechanisms by which herbal compound and monomeric components delay of lumbar intervertebral disc degeneration include improving the intervertebral disc microenvironment, promoting the synthesis of aggregated proteoglycans and type Ⅱ collagen in the intervertebral disc, reducing the degradation of the extracellular matrix, and inhibiting apoptosis in the nucleus pulposus cells, etc. The main signaling pathways involved include Wnt/ß-catenin signaling pathway, MAPK-related signaling pathway, mTOR signaling pathway, Fas/FasL signaling pathway, PI3 K/Akt signaling pathway, NF-κB signaling pathway, JAK/STAT signaling pathway, and hedgehog signaling pathway, etc.

The Raw Mixed Conducting Interphase Affords Effective Prelithiation in Working Batteries.

Contact prelithiation is an important strategy to compensate the initial capacity loss of lithium-ion batteries. However, the dead Li generated from inadequate Li conversion reduces the cycling stability of rechargeable batteries. Herein a mono-solvent dimethyl carbonate (DMC) electrolyte was employed in contact prelithiation for the first time. We discover that the low-organic-content raw electrolyte interphase (REI) induced by this electrolyte on Li source and anode is a mixed ion/electron conductor. Therefore, electron channels can be maintained even when the Li source has been completely wrapped by the DMC-derived REI. As a result, an outstanding Li source utilization of 92.8 % and a negligible dead Li yield can be realized. This strategy renders batteries with a very high initial Coulombic efficiency (90.0 %) and an excellent capacity retention (94.9 %) over 210 cycles, highlighting the significance of REI for effective contact prelithiation.

Anomalous Redox Features Induced by Strong Covalency in Layered NaTi1-y Vy S2 Cathodes for Na-Ion Batteries.

The rising demand for energy density of cathodes means the need to raise the voltage or capacity of cathodes. Transition metal (TM) doping has been employed to enhance the electrochemical properties in multiple aspects. The redox voltage of doped cathodes usually falls in between the voltage of undoped layered cathodes. However, we found anomalous redox features in NaTi1-y Vy S2 . The first discharge platform potential (2.4 V) is significantly higher than that of undoped NaTiS2 and NaVS2 (both around 2.2 V), and the energy density is raised by 15 %. We speculate that the anomalous voltage is mainly attributed to the strong hybridization in the Ti-V-S system. Ti3+ and V3+ undergo charge transfer and form a more stable Ti (t2g 0 eg 0 ) and V (t2g 3 eg 0 ) electronic configuration. Our results indicate that higher voltage of cathode materials could be achieved by strong TM-ligand covalency, and this conclusion provides possible opportunities to explore high voltage materials for future layered cathodes.

Pesticide dose based on canopy characteristics in apple trees: Reducing environmental risk by reducing the amount of pesticide while maintaining pest and disease control efficacy.

Although many different designed air-assisted sprayers can be used for pesticide application in apple orchards, the lack of adequate adjustments according to specific crop characteristics leads to application inefficiencies and failures. To evaluate the spray coverage and biological efficacy of different application techniques combined with an alternative dosage adjustment based on tree row volume (TRV), field tests with five different techniques were carried out at three crop stages on a commercial apple orchard. The results showed that conventional mist-blower with a high application volume (800 L ha-1) exhibited an excessive coverage with a high risk of contamination at the early crop stage (BBCH19), whereas other treatments using different application techniques, with a reduced volume rate and pesticide dose of 75%, were equivalent with good uniformity, revealing the great importance of suitable adjustment for the sprayers. For the middle and late stages (BBCH64 and 75), the orchard sprayer equipped with vertical booms provided the maximum coverage, and the pneumatic sprayer achieved significantly higher impacts density, which revealed their advantages and high efficiency for dense apple trees. The newly developed multi-fan sprayer and pneumatic sprayer achieved consistent coverage during the entire crop stage, independent of the changes in canopy structure (TRV). This indicates that a suitable setting and adjustment of the sprayer can contribute to a consistent spray quality. In general, benefiting from these new spraying technologies, an average reduction of 60.7% in pesticide dose and volume rate were achieved within the entire season, maintaining the same threshold of pest and disease control as that of the higher reference dose normally applied. These results demonstrate the importance of an alternative dose adjustment method to meet the requirements of the Farm to Fork strategy.

Anionic Redox Regulated via Metal-Ligand Combinations in Layered Sulfides.

The increasing demand for energy storage is calling for improvements in cathode performance. In traditional layered cathodes, the higher energy of the metal 3d over the O 2p orbital results in one-band cationic redox; capacity solely from cations cannot meet the needs for higher energy density. Emerging anionic redox chemistry is promising to access higher capacity. In recent studies, the low-lying O nonbonding 2p orbital was designed to activate one-band oxygen redox, but they are still accompanied by reversibility problems like oxygen loss, irreversible cation migration, and voltage decay. Herein, by regulating the metal-ligand energy level, both extra capacities provided by anionic redox and highly reversible anionic redox process are realized in NaCr1- y Vy S2 system. The simultaneous cationic and anionic redox of Cr/V and S is observed by in situ X-ray absorption near edge structure (XANES). Under high d-p hybridization, the strong covalent interaction stabilizes the holes on the anions, prevents irreversible dimerization and cation migration, and restrains voltage hysteresis and voltage decay. The work provides a fundamental understanding of highly reversible anionic redox in layered compounds, and demonstrates the feasibility of anionic redox chemistry based on hybridized bands with d-p covalence.

Research progress in mechanism of Chinese herbal compounds and monomers in delaying lumbar intervertebral disc degeneration / 中国中药杂志

Traditional Chinese medicine has unique advantages in the treatment of degenerative bone and joint diseases, and its widely used in clinical practice. In recent years, many scholars have conducted a large number of basic studies on the delay of intervertebral disc degeneration by herbal compound and monomeric components from different perspectives. In order to further elucidate its mechanism of action, this paper summarizes the in vivo and in vitro experimental studies conducted at the level of both herbal compound and single components, respectively, in order to provide references for the basic research on the treatment of lumbar intervertebral disc degeneration by Chinese medicine. A summary shows that commonly used herbal compound prescriptions include both classical prescriptions such as Duhuo Jisheng Decoction, as well as clinical experience prescriptions such as Yiqi Huoxue Recipe. Angelicae Sinensis Radix, Chuanxiong Rhizoma, Rehmanniae Radix Praeparata, Achyranthis Bidentatae Radix, and Eucommiae Cortex were used most frequently. Tonic for deficiency and blood stasis activators were used most frequently. The most utilized monomeric components include icariin, ginsenoside Re, salvianolic acid B and aucubin. The main molecular mechanisms by which herbal compound and monomeric components delay of lumbar intervertebral disc degeneration include improving the intervertebral disc microenvironment, promoting the synthesis of aggregated proteoglycans and type Ⅱ collagen in the intervertebral disc, reducing the degradation of the extracellular matrix, and inhibiting apoptosis in the nucleus pulposus cells, etc. The main signaling pathways involved include Wnt/β-catenin signaling pathway, MAPK-related signaling pathway, mTOR signaling pathway, Fas/FasL signaling pathway, PI3 K/Akt signaling pathway, NF-κB signaling pathway, JAK/STAT signaling pathway, and hedgehog signaling pathway, etc.

The complete chloroplast genome of Carex agglomerata C. B. Clarke (Cyperaceae), an endemic species from China.

Carex agglomerata C. B. Clarke is a sedge with excellent ornamental characters, it is an important ecosystem stabilizer. Here we report the complete chloroplast genome of C. agglomerata to provide a foundation for further phylogenetic studies on the Cyperaceae. The chloroplast (cp) genome is 184,157 bp in size and consists of a large single-copy (LSC) region 106,654 bp in length, a small single-copy (SSC) region of 36,099 bp, two inverted repeats (IR) regions each 20,702 bp. The total GC content of the cp genome is 33.9% with the LSC, SSC, and IR regions 32, 32.5, and 42.9%, respectively. The cp genome contains 128 genes, including 80 protein-coding, 40 tRNA, and eight rRNA genes. The phylogenetic analysis showed C. agglomerata is in a clade with Carex neurocarpa Maxim and Carex siderosticta Hance. This study provides a basis for further phylogenetic studies of Carex.

Stabilizing Transition Metal Vacancy Induced Oxygen Redox by Co2+ /Co3+ Redox and Sodium-Site Doping for Layered Cathode Materials.

Anionic redox is an effective way to boost the energy density of layer-structured metal-oxide cathodes for rechargeable batteries. However, inherent rigid nature of the TMO6 (TM: transition metals) subunits in the layered materials makes it hardly tolerate the inner strains induced by lattice glide, especially at high voltage. Herein, P2-Na0.8 Mg0.13 [Mn0.6 Co0.2 Mg0.07 □0.13 ]O2 (□: TM vacancy) is designed that contains vacancies in TM sites, and Mg ions in both TM and sodium sites. Vacancies make the rigid TMO6 octahedron become more asymmetric and flexible. Low valence Co2+ /Co3+ redox couple stabilizes the electronic structure, especially at the charged state. Mg2+ in sodium sites can tune the interlayer spacing against O-O electrostatic repulsion. Time-resolved in situ X-ray diffraction confirms that irreversible structure evolution is effectively suppressed during deep desodiation benefiting from the specific configuration. X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations demonstrate that, deriving from the intrinsic vacancies, multiple local configurations of "□-O-□", "Na-O-□", "Mg-O-□" are superior in facilitating the oxygen redox for charge compensation than previously reported "Na-O-Mg". The resulted material delivers promising cycle stability and rate capability, with a long voltage plateau at 4.2 V contributed by oxygen, and can be well maintained even at high rates. The strategy will inspire new ideas in designing highly stable cathode materials with reversible anionic redox for sodium-ion batteries.

Boosting Reversibility of Mn-Based Tunnel-Structured Cathode Materials for Sodium-Ion Batteries by Magnesium Substitution.

Electrochemical irreversibility and sluggish mobility of Na+ in the cathode materials result in poor cycle stability and rate capability for sodium-ion batteries. Herein, a new strategy of introducing Mg ions into the hinging sites of Mn-based tunnel-structured cathode material is designed. Highly reversible electrochemical reaction and phase transition in this cathode are realized. The resulted Na0.44Mn0.95Mg0.05O2 with Mg2+ in the hinging Mn-O5 square pyramidal exhibits promising cycle stability and rate capability. At a current density of 2 C, 67% of the initial discharge capacity is retained after 800 cycles (70% at 20 C), much improved than the undoped Na0.44MnO2. The improvement is attribute to the enhanced Na+ diffusion kinetics and the lowered desodiation energy after Mg doping. Highly reversible charge compensation and structure evolution are proved by synchrotron-based X-ray techniques. Differential charge density and atom population analysis of the average electron number of Mn indicate that Na0.44Mn0.95Mg0.05O2 is more electron-abundant in Mn 3d orbits near the Fermi level than that in Na0.44MnO2, leading to higher redox participation of Mn ions.

Whole-Voltage-Range Oxygen Redox in P2-Layered Cathode Materials for Sodium-Ion Batteries.

Oxygen-redox of layer-structured metal-oxide cathodes has drawn great attention as an effective approach to break through the bottleneck of their capacity limit. However, reversible oxygen-redox can only be obtained in the high-voltage region (usually over 3.5 V) in current metal-oxide cathodes. Here, we realize reversible oxygen-redox in a wide voltage range of 1.5-4.5 V in a P2-layered Na0.7 Mg0.2 [Fe0.2 Mn0.6 □0.2 ]O2 cathode material, where intrinsic vacancies are located in transition-metal (TM) sites and Mg-ions are located in Na sites. Mg-ions in the Na layer serve as "pillars" to stabilize the layered structure during electrochemical cycling, especially in the high-voltage region. Intrinsic vacancies in the TM layer create the local configurations of "□-O-□", "Na-O-□" and "Mg-O-□" to trigger oxygen-redox in the whole voltage range of charge-discharge. Time-resolved techniques demonstrate that the P2 phase is well maintained in a wide potential window range of 1.5-4.5 V even at 10 C. It is revealed that charge compensation from Mn- and O-ions contributes to the whole voltage range of 1.5-4.5 V, while the redox of Fe-ions only contributes to the high-voltage region of 3.0-4.5 V. The orphaned electrons in the nonbonding 2p orbitals of O that point toward TM-vacancy sites are responsible for reversible oxygen-redox, and Mg-ions in Na sites suppress oxygen release effectively.