The cerebellum computes frequency dynamics for motions with numerical precision and cross-individual uniformity.

Cross-individual variability is considered the essence of biology, preventing precise mathematical descriptions of biological motion like the physics law of motion. Here we report that the cerebellum shapes motor kinematics by encoding dynamic motor frequencies with remarkable numerical precision and cross-individual uniformity. Using in-vivo electrophysiology and optogenetics in mice, we confirmed that deep cerebellar neurons encoded frequencies via populational tuning of neuronal firing probabilities, creating cerebellar oscillations and motions with matched frequencies. The mechanism was consistently presented in self-generated rhythmic and non-rhythmic motions triggered by a vibrational platform, or skilled tongue movements of licking in all tested mice with cross-individual uniformity. The precision and uniformity allowed us to engineer complex motor kinematics with designed frequencies. We further validated the frequency-coding function of the human cerebellum using cerebellar electroencephalography recordings and alternating-current stimulation during voluntary tapping tasks. Our findings reveal a cerebellar algorithm for motor kinematics with precision and uniformity, the mathematical foundation for brain-computer interface for motor control.

Tetradentate Pt(II) complexes based on xylenylamino linked dual pyrazolate chelates for organic light emitting diodes.

In this work, we report the syntheses of three Pt(II) emitters, namely, Pt4N1, Pt4N2, and Pt4N3, to which their tetradentate chelates were assembled by linking two pyrazolate chelates with a single xylenylamino entity. Functionalization of Pt4N1 was achieved upon addition of electronegative CF3 substituent on pyridinyl groups and switching to more electron deficient pyrazinyl groups in giving Pt4N2 and Pt4N3, respectively. The vertical arranged xylenylamino entity has effectively suppressed the inter-molecular π-π stacking and Pt···Pt interaction, as shown by the single crystal X-ray structural analyses. Upon fabrication of OLED devices, Pt4N2 and Pt4N3 based devices delivered efficient cyan and green emission, with an EQEmax of 15.2% and 11.2%, respectively, affirming the successfulness of the tetradentate chelating strategy.

T cell exhaustion in human cancers.

T cell exhaustion refers to a progressive state in which T cells become functionally impaired due to sustained antigenic stimulation, which is characterized by increased expression of immune inhibitory receptors, but weakened effector functions, reduced self-renewal capacity, altered epigenetics, transcriptional programme and metabolism. T cell exhaustion is one of the major causes leading to immune escape of cancer, creating an environment that supports tumor development and metastatic spread. In addition, T cell exhaustion plays a pivotal role to the efficacy of current immunotherapies for cancer. This review aims to provide a comprehensive view of roles of T cell exhaustion in cancer development and progression. We summerized the regulatory mechanisms that involved in T cell exhaustion, including transcription factors, epigenetic and metabolic reprogramming events, and various microenvironmental factors such as cytokines, microorganisms, and tumor autocrine substances. The paper also discussed the challenges posed by T cell exhaustion to cancer immunotherapies, including immune checkpoint blockade (ICB) therapies and chimeric antigen receptor T cell (CAR-T) therapy, highlightsing the obstacles encountered in ICB therapies and CAR-T therapies due to T cell exhaustion. Finally, the article provides an overview of current therapeutic options aimed to reversing or alleviating T cell exhaustion in ICB and CAR-T therapies. These therapeutic approaches seek to overcome T cell exhaustion and enhance the effectiveness of immunotherapies in treating tumors.

Combined Chemotherapy and Immunotherapy Induction for Screening of Patients with Cervical Esophageal Carcinoma for Subsequent Local Treatment: A New Treatment Paradigm.

BACKGROUND: Definitive chemoradiotherapy is recommended as the primary treatment for cervical esophageal carcinoma (CEC). However, local control rates remain unsatisfactory for some patients. Therefore, in this study, we introduced a new treatment paradigm for individuals with CEC, customizing the choice between subsequent local treatments based on their response to induction chemotherapy and immunotherapy. PATIENTS AND METHODS: Induction treatment comprised two to four cycles of chemotherapy combined with programmed cell death protein 1 (PD-1) inhibitors. Patients achieving complete response (CR) or near CR after induction treatment underwent definitive chemoradiotherapy (dCRT), while those not achieving CR or near CR underwent surgical resection. RESULTS: Among the 40 eligible patients, 14 (35.0%) achieved a CR or near CR after induction treatment. Of the ten patients achieving a CR or near CR, one developed an esophageal fistula after dCRT (10.0%). Among the eight non-CR or non-near CR patients receiving chemoradiotherapy, six developed esophageal fistula (75.0%). Among the 26 patients who did not achieve CR or near CR after induction treatment, the 1-year cancer specific survival (CSS) rates were 93.3% [95% confidence interval (CI) 0.815-1%] for the 18 patients in the surgery group, and 71.4% (95% CI 0.447-1%) for the 8 patients in the chemoradiotherapy group (p = 0.027). The overall laryngeal preservation rate was 85.0% (34/40), with a functional laryngeal preservation rate of 77.5% (31/40). CONCLUSION: The approach consisting of combined immunotherapy and chemotherapy successfully identified patients who were responding well to induction treatment and who were sensitive to radiotherapy, for chemoradiotherapy; thus, improving laryngeal preservation rates. In addition, it also identified patients with poor responses to induction treatment and radiotherapy, for timely surgery; hence, reducing radiotherapy complications and enhancing survival.

Advances in Small-Molecule Dual Inhibitors Targeting EGFR and HER2 Receptors as Anti-Cancer Agents.

As members of the protein tyrosine kinase family, the Epidermal Growth Factor Receptor (EGFR) and Human Epidermal Growth Factor Receptor 2 (HER2) play essential roles in cellular signal transduction pathways. Overexpression or abnormal activation of EGFR and HER2 can lead to the development of various solid tumors. Therefore, they have been confirmed as biological targets for the development of anticancer drugs. Due to the fact that many cancers are highly susceptible to developing resistance to single-target EGFR inhibitors in clinical practice, dual inhibitors that target both EGFR and HER2 have been developed to increase efficacy, reduce drug resistance and interactions, and improve patient compliance. Currently, a variety of EGFR/HER2 dual inhibitors have been developed, with several drugs already approved for marketing or in clinical trials. In this review, we summarize recent advancements in small-molecule EGFR/HER2 dual inhibitors by focusing on structure-activity relationships and share novel insights into developing anticancer agents.

Regulatory mechanisms of PD-1/PD-L1 in cancers.

Immune evasion contributes to cancer growth and progression. Cancer cells have the ability to activate different immune checkpoint pathways that harbor immunosuppressive functions. The programmed death protein 1 (PD-1) and programmed cell death ligands (PD-Ls) are considered to be the major immune checkpoint molecules. The interaction of PD-1 and PD-L1 negatively regulates adaptive immune response mainly by inhibiting the activity of effector T cells while enhancing the function of immunosuppressive regulatory T cells (Tregs), largely contributing to the maintenance of immune homeostasis that prevents dysregulated immunity and harmful immune responses. However, cancer cells exploit the PD-1/PD-L1 axis to cause immune escape in cancer development and progression. Blockade of PD-1/PD-L1 by neutralizing antibodies restores T cells activity and enhances anti-tumor immunity, achieving remarkable success in cancer therapy. Therefore, the regulatory mechanisms of PD-1/PD-L1 in cancers have attracted an increasing attention. This article aims to provide a comprehensive review of the roles of the PD-1/PD-L1 signaling in human autoimmune diseases and cancers. We summarize all aspects of regulatory mechanisms underlying the expression and activity of PD-1 and PD-L1 in cancers, including genetic, epigenetic, post-transcriptional and post-translational regulatory mechanisms. In addition, we further summarize the progress in clinical research on the antitumor effects of targeting PD-1/PD-L1 antibodies alone and in combination with other therapeutic approaches, providing new strategies for finding new tumor markers and developing combined therapeutic approaches.

Acacetin alleviates autoimmune myocarditis by regulating CD4+ T cell mitochondrial respiration.

BACKGROUND: Myocarditis refers to an autoimmune inflammatory response of the myocardium with characterization of self-reactive CD4+ T cell activation, which lacks effective treatment and has a poor prognosis. Acacetin is a natural flavonoid product that has been reported to have anti-inflammatory effects. However, acacetin has not been investigated in myocarditis. METHODS: Oral acacetin treatment was administered in an experimental autoimmune myocarditis model established with myosin heavy chain-alpha peptide. Echocardiography, pathological staining, and RT-qPCR were used to detect cardiac function, myocardial injury, and inflammation levels. Flow cytometry was utilized to detect the effect of acacetin on CD4+ T cell function. RNA-seq, molecular docking, and microscale thermophoresis (MST) were employed to investigate potential mechanisms. Seahorse analysis, mitoSOX, JC-1, and mitotracker were utilized to detect the effect of acacetin on mitochondrial function. RESULTS: Acacetin attenuated cardiac injury and fibrosis as well as heart dysfunction, and reduced cardiac inflammatory cytokines and ratio of effector CD4+ T and Th17 cells. Acacetin inhibited CD4+ T cell activation, proliferation, and Th17 cell differentiation. Mechanistically, the effects of acacetin were related to reducing mitochondrial complex II activity thereby inhibiting mitochondrial respiration and mitochondrial reactive oxygen species in CD4+ T cells. CONCLUSION: Acacetin may be a valuable therapeutic drug in treating CD4+ T cell-mediated myocarditis.

Neuronal population activity in the olivocerebellum encodes the frequency of essential tremor in mice and patients.

Essential tremor (ET) is the most prevalent movement disorder, characterized primarily by action tremor, an involuntary rhythmic movement with a specific frequency. However, the neuronal mechanism underlying the coding of tremor frequency remains unexplored. Here, we used in vivo electrophysiology, optogenetics, and simultaneous motion tracking in the Grid2dupE3 mouse model to investigate whether and how neuronal activity in the olivocerebellum determines the frequency of essential tremor. We report that tremor frequency was encoded by the temporal coherence of population neuronal firing within the olivocerebellums of these mice, leading to frequency-dependent cerebellar oscillations and tremors. This mechanism was precise and generalizable, enabling us to use optogenetic stimulation of the deep cerebellar nuclei to induce frequency-specific tremors in wild-type mice or alter tremor frequencies in tremor mice. In patients with ET, we showed that deep brain stimulation of the thalamus suppressed tremor symptoms but did not eliminate cerebellar oscillations measured by electroencephalgraphy, indicating that tremor-related oscillations in the cerebellum do not require the reciprocal interactions with the thalamus. Frequency-disrupting transcranial alternating current stimulation of the cerebellum could suppress tremor amplitudes, confirming the frequency modulatory role of the cerebellum in patients with ET. These findings offer a neurodynamic basis for the frequency-dependent stimulation of the cerebellum to treat essential tremor.

Effect of tocilizumab plus corticosteroid on clinical outcome in patients hospitalized with severe fever with thrombocytopenia syndrome: A randomized clinical trial.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging viral hemorrhagic fever with high fatality rates. The blockade of pro-inflammatory cytokines presents a promising therapeutic strategy. METHODS: We conducted a randomized clinical trial at the 154th hospital, Xinyang, Henan Province. Eligible patients with severe SFTS disease were randomly assigned in a 1:2 ratio to receive either a single intravenous infusion of tocilizumab plus usual care; or usual care only. The primary outcome was the clinical status of death/survival at day 14, while secondary outcomes included improvement from baseline in liver and kidney damage and time required for hospital discharge. The efficacy of tocilizumab plus corticosteroid was compared to those receiving corticosteroid alone. The trial is registered with the Chinese Clinical Trial Registry website (ChiCTR2300076317). RESULTS: 63 eligible patients were assigned to the tocilizumab group and 126 to the control group. The addition of tocilizumab to usual care was associated with a reduced death rate (9.5%) compared to those received only usual care (23.0%), with an adjusted hazard ratio (aHR) of 0.37 (95% confidence interval [CI], 0.15 to 0.91, P = 0.029). Combination therapy of tocilizumab and corticosteroids was associated with a significantly reduced fatality (aHR, 0.21; 95% CI, 0.08 to 0.56; P = 0.002) compared to those receiving corticosteroids alone. CONCLUSIONS: A significant benefit of reducing fatality in severe SFTS patients was observed by using tocilizumab. A combined therapy of tocilizumab plus corticosteroids was recommended for the therapy of severe SFTS.

N-ethyl-N-nitrosourea (ENU)-induced C-terminal truncation of Runx3 results in autoimmune colitis associated with Th17/Treg imbalance.

Inflammatory bowel disease (IBD) is a chronic and progressive inflammatory intestinal disease that affects people around the world. The primary cause of IBD is an imbalance in the host immune response to intestinal flora. Several human genes, including IL10, STAT3, IRGM, ATG16L1, NOD2 and RUNX3, are associated with inappropriate immune responses in IBD. It has been reported that homozygous Runx3-knockout (ko) mice spontaneously develop colitis. However, the high mortality rate in these mice within the first two weeks makes it challenging to study the role of Runx3 in colitis. To address this issue, a spontaneous colitis (SC) mouse model carrying a C-terminal truncated form of Runx3 with Tyr319stop point mutation has been generated. After weaning, SC mice developed spontaneous diarrhea and exhibited prominent enlargement of the colon, accompanied by severe inflammatory cell infiltration. Results of immunofluorescence staining showed massive CD4+ T cell infiltration in the inflammatory colon of SC mice. Colonic IL-17A mRNA expression and serum IL-17A level were increased in SC mice. CD4+ T cells from SC mice produced stronger IL-17A than those from wildtype mice in Th17-skewing conditions in vitro. In addition, the percentages of Foxp3+ Treg cells as well as the RORγt+Foxp3+ Treg subset, known for its role in suppressing Th17 response in the gut, were notably lower in colon lamina propria of SC mice than those in WT mice. Furthermore, transfer of total CD4+ T cells from SC mice, but not from wildtype mice, into Rag1-ko host mice resulted in severe autoimmune colitis. In conclusion, the C-terminal truncated Runx3 caused autoimmune colitis associated with Th17/Treg imbalance. The SC mouse model is a feasible approach to investigate the effect of immune response on spontaneous colitis.

Effects of Helicobacter pylori and Moluodan on the Wnt/ß-catenin signaling pathway in mice with precancerous gastric cancer lesions.

BACKGROUND: Helicobacter pylori (H. pylori) is the primary risk factor for gastric cancer (GC), the Wnt/ß-Catenin signaling pathway is closely linked to tumourigenesis. GC has a high mortality rate and treatment cost, and there are no drugs to prevent the progression of gastric precancerous lesions to GC. Therefore, it is necessary to find a novel drug that is inexpensive and preventive to against GC. AIM: To explore the effects of H. pylori and Moluodan on the Wnt/ß-Catenin signaling pathway and precancerous lesions of GC (PLGC). METHODS: Mice were divided into the control, N-methyl-N-nitrosourea (MNU), H. pylori + MNU, and Moluodan groups. We first created an H. pylori infection model in the H. pylori + MNU and Moluodan groups. A PLGC model was created in the remaining three groups except for the control group. Moluodan was fed to mice in the Moloudan group ad libitum. The general condition of mice were observed during the whole experiment period. Gastric tissues of mice were grossly and microscopically examined. Through quantitative real-time PCR (qRT-PCR) and Western blotting analysis, the expression of relevant genes were detected. RESULTS: Mice in the H. pylori + MNU group showed the worst performance in general condition, gastric tissue visual and microscopic observation, followed by the MNU group, Moluodan group and the control group. QRT-PCR and Western blotting analysis were used to detect the expression of relevant genes, the results showed that the H. pylori + MNU group had the highest expression, followed by the MNU group, Moluodan group and the control group. CONCLUSION: H. pylori can activate the Wnt/ß-catenin signaling pathway, thereby facilitating the development and progression of PLGC. Moluodan suppressed the activation of the Wnt/ß-catenin signaling pathway, thereby decreasing the progression of PLGC.

Budesonide Induces Favourable Histologic and Symptomatic Recovery in Patients with Non-responsive and Refractory Coeliac Disease When Given in an Open Capsule Format.

INTRODUCTION: Non-responsive coeliac disease (NRCD), where symptoms and enteropathy persist despite a prolonged gluten-free diet (GFD), is common. Refractory coeliac disease (RCD), characterised by malabsorption and extensive enteropathy, is rare but serious. In both, treatment options are limited. Topical budesonide may help and an open capsule format promoting proximal small intestinal delivery may be advantageous. AIM: To describe the effect of budesonide and its presentation on mucosal healing, symptoms, and tolerability in NRCD and RCD. METHODS: A retrospective cohort study of NRCD and RCD patients who received budesonide for enteropathy despite a strict GFD for over 12 months. Primary outcome was improvement in histology. Symptoms and adverse treatment effects were recorded. RESULTS: 50 patients with NRCD (n = 14; 86% F), RCD type 1 (n = 30; 60% F), and RCD type 2 (n = 6 based on aberrant duodenal T cells; 33% F) were identified. Common RCD symptoms were diarrhoea (68%), fatigue (40%), and weight loss (34%). 16 received closed capsule budesonide (CCB) 9 mg OD and 35 open capsule budesonide (OCB) 3 mg 3 times a day. Complete and partial mucosal healing was significantly higher after OCB compared to CCB (p < 0.001, Mann-Whitney U test). Symptom improvement was also significantly higher after OCB compared to CCB (p = 0.002, Mann-Whitney U test). Side effects were mild and self-limiting and were reported in 25% of both cohorts. CONCLUSION: OCB was well tolerated and associated with improvements in enteropathy (83%) and symptoms (90%) in NRCD and RCD. Our findings support OCB as the preferred 1st-line therapy for NRCD and RCD type 1.

Antitumor mechanisms and future clinical applications of the natural product triptolide.

Triptolide (TPL) is a compound sourced from Tripterygium wilfordii Hook. F., a traditional Chinese medicinal herb recognized for its impressive anti-inflammatory, anti-angiogenic, immunosuppressive, and antitumor qualities. Notwithstanding its favorable attributes, the precise mechanism through which TPL influences tumor cells remains enigmatic. Its toxicity and limited water solubility significantly impede the clinical application of TPL. We offer a comprehensive overview of recent research endeavors aimed at unraveling the antitumor mechanism of TPL in this review. Additionally, we briefly discuss current strategies to effectively manage the challenges associated with TPL in future clinical applications. By compiling this information, we aim to enhance the understanding of the underlying mechanisms involved in TPL and identify potential avenues for further advancement in antitumor therapy.

Decoding the influence of low temperature on biofilm development: The hidden roles of c-di-GMP.

Biofilms are widely used and play important roles in biological processes. Low temperature of wastewater inhibits the development of biofilms derived from wastewater activated sludge. However, the specific mechanism of temperature on biofilm development is still unclear. This study explored the mechanism of temperature on biofilm development and found a feasible method to enhance biofilm development at low temperature. The amount of biofilm development decreased by approximately 66 % and 55 % at 4 °C and 15 °C, respectively, as compared to 28 °C. The cyclic dimeric guanosine monophosphate (c-di-GMP) concentration also decreased at low temperature and was positively correlated with extracellular polymeric substance (EPS) content, formation, and adhesion strength. Microbial community results showed that low temperature inhibited the normal survival of most microorganisms, but promoted the growth of some psychrophile bacteria like Sporosarcina, Caldilineaceae, Gemmataceae, Anaerolineaceae and Acidobacteriota. Further analysis of functional genes demonstrated that the abundance of functional genes related to the synthesis of c-di-GMP (K18968, K18967 and K13590) decreased at low temperature. Subsequently, the addition of exogenous spermidine increased the level of intracellular c-di-GMP and alleviated the inhibition effect of low temperature on biofilm development. Therefore, the possible mechanism of low temperature on biofilm development could be the inhibition of the microorganism activity and reduction of the communication level between cells, which is the closely related to the EPS content, formation, and adhesion strength. The enhancement of c-di-GMP level through the exogenous addition of spermidine provides an alternative strategy to enhance biofilm development at low temperatures. The results of this study enhance the understanding of the influence of temperature on biofilm development and provide possible strategies for enhancing biofilm development at low temperatures.

High-efficient separation of deoxyribonucleic acid from pathogenic bacteria by hedgehog-inspired magnetic nanoparticles microextraction.

Efficient separation of deoxyribonucleic acid (DNA) through magnetic nanoparticles (MN) is a widely used biotechnology. Hedgehog-inspired MNs (HMN) possess a high-surface-area due to the distinct burr-like structure of hedgehog, but there is no report about the usage of HMN for DNA extraction. Herein, to improve the selection of MN and illustrate the performance of HMN for DNA separation, HMN and silica-coated Fe3O4 nanoparticles (Fe3O4@SiO2) were fabricated and compared for the high-efficient separation of pathogenic bacteria of DNA. Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) are typical Gram-negative and Gram-positive bacteria and are selected as model pathogenic bacteria. To enhance the extraction efficiency of two kinds of MNs, various parameters, including pretreatment, lysis, binding and elution conditions, have been optimized in detail. In most separation experiments, the DNA yield of HMN was higher than that of Fe3O4@SiO2. Therefore, a HMN-based magnetic solid-phase microextraction (MSPE) and quantitative real-time PCR (qPCR) were integrated and used to detect pathogenic bacteria in real samples. Interestingly, the HMN-based MSPE combined qPCR strategy exhibited high sensitivity with a limit of detection of 2.0 × 101 CFU mL-1 for E. coli and 4.0 × 101 CFU mL-1 for S. aureus in orange juice, and 2.8 × 102 CFU mL-1 for E. coli and 1.1 × 102 CFU mL-1 for S. aureus in milk, respectively. The performance of the proposed strategy was significantly better than that of commercial kit. This work could prove that the novel HMN could be applicable for the efficient separation of DNA from complex biological samples.

Extending the diabetic retinopathy screening intervals in Singapore: methodology and preliminary findings of a cohort study.

BACKGROUND: The Diabetic Retinopathy Extended Screening Study (DRESS) aims to develop and validate a new DR/diabetic macular edema (DME) risk stratification model in patients with Type 2 diabetes (DM) to identify low-risk groups who can be safely assigned to biennial or triennial screening intervals. We describe the study methodology, participants' baseline characteristics, and preliminary DR progression rates at the first annual follow-up. METHODS: DRESS is a 3-year ongoing longitudinal study of patients with T2DM and no or mild non-proliferative DR (NPDR, non-referable) who underwent teleophthalmic screening under the Singapore integrated Diabetic Retinopathy Programme (SiDRP) at four SingHealth Polyclinics. Patients with referable DR/DME (> mild NPDR) or ungradable fundus images were excluded. Sociodemographic, lifestyle, medical and clinical information was obtained from medical records and interviewer-administered questionnaires at baseline. These data are extracted from medical records at 12, 24 and 36 months post-enrollment. Baseline descriptive characteristics stratified by DR severity at baseline and rates of progression to referable DR at 12-month follow-up were calculated. RESULTS: Of 5,840 eligible patients, 78.3% (n = 4,570, median [interquartile range [IQR] age 61.0 [55-67] years; 54.7% male; 68.0% Chinese) completed the baseline assessment. At baseline, 97.4% and 2.6% had none and mild NPDR (worse eye), respectively. Most participants had hypertension (79.2%) and dyslipidemia (92.8%); and almost half were obese (43.4%, BMI ≥ 27.5 kg/m2). Participants without DR (vs mild DR) reported shorter DM duration, and had lower haemoglobin A1c, triglycerides and urine albumin/creatinine ratio (all p < 0.05). To date, we have extracted 41.8% (n = 1909) of the 12-month follow-up data. Of these, 99.7% (n = 1,904) did not progress to referable DR. Those who progressed to referable DR status (0.3%) had no DR at baseline. CONCLUSIONS: In our prospective study of patients with T2DM and non-referable DR attending polyclinics, we found extremely low annual DR progression rates. These preliminary results suggest that extending screening intervals beyond 12 months may be viable and safe for most participants, although our 3-year follow up data are needed to substantiate this claim and develop the risk stratification model to identify low-risk patients with T2DM who can be assigned biennial or triennial screening intervals.

[Soil microbial carbon pump conceptual framework 2.0]. / 土壤微生物碳泵概念体系2.0.

Microorganisms are essential actors in the biogeochemical cycling of elements within terrestrial ecosystems, with significant influences on soil health, food security, and global climate change. The contribution of microbial anabolism-induced organic compounds is a non-negligible factor in the processes associated with soil carbon (C) storage and organic matter preservation. In recent years, the conceptual framework of soil microbial carbon pump (MCP), with a focus on microbial metabolism and necromass generation process, has gained widespread attention. It primarily describes the processes of soil organic C formation and stabilization driven by the metabolic activities of soil heterotrophic microorganisms, representing an important mechanism and a focal point in current research on terrestrial C sequestration. Here, we reviewed the progress in this field and introduced the soil MCP conceptual framework 2.0, which expands upon the existing MCP model by incorporating autotrophic microbial pathway for C sequestration and integrating the concept of soil mineral C pump. These advancements aimed to enrich and refine our understanding of microbial-mediated terrestrial ecosystem C cycling and sequestration mechanisms. This refined framework would provide theoretical support for achieving China's "dual carbon" goals.

[Accumulation of microbial necromass carbon and their contribution to soil organic carbon in different vegetation types on the Loess Plateau, Northwest China]. / é»„åœŸé«˜åŽŸä¸åŒæ¤è¢«ç±»åž‹åœŸå£¤å¾®ç”Ÿç‰©æ®‹ä½“ç¢³çš„ç§¯ç´¯åŠå ¶å¯¹æœ‰æœºç¢³çš„è´¡çŒ®.

Microbial necromass carbon (MNC) is an important contributor to soil organic carbon (SOC). Soil carbon storage has increased significantly since the return of farmland to forestland (grassland) on the Loess Plateau. However, the contribution of MNC to SOC accumulation in different vegetation types and the influence factors remain unclear. Herein, we used the biomarker (amino sugar) technique to determine the MNC content and analyzed the influencing factors in 0-5 cm and 5-20 cm soil layers of natural grassland, shrubland (Caragana microphylla), and forestland (Quercus liaodongensis) in the Loess Plateau. The results showed that: 1) the soil pH decreased significantly from grassland to shrubland and then to forestland within the same soil layer. However, the SOC, total nitrogen (TN), microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN) contents showed a reverse trend, with forestland displaying the highest values followed by shrubland and then grassland. The 0-5 cm had significantly higher values than the 5-20 cm depth. 2) The MNC contents varied 0.69-16.41 g·kg-1 in the two soil horizons of the three vegetation types. There were significant increases in the contents of bacterial necromass carbon (BNC), fungal necromass carbon (FNC), and MNC in the 0-5 cm soil from grassland, shrubland to forestland. The contents of MBC were 1.9 times higher in forestland than in shrubland, and 3.2 times higher in shrubland than in grassland. In the 5-20 cm soil layer, the contents of FNC and MBC were significantly higher in the forestland than in the shrubland and grassland. The FNC content was significantly higher than that of the BNC, ranging from 1.16 to 9.83 times greater than the BNC. 3) The contribution of MNC to SOC was 0.6 and 0.7 times higher in shrubland and forestland than in grassland, respectively, with FNC accounting for 15.2%-42.7%, and BNC accounting for 1.4%-7.4%. 4) pH, TN, MBC, and MBN were important factors that influenced MNC accumulation. In summary, the variation in vegetation type altered soil nutrients, microbial activity, and soil pH, resulting in forestland and shrubland being more beneficial to the formation and accumulation of MNC, which was dominated by fungi, compared to grassland.