Application of microwave ablation assisted degradation therapy in surgical treatment of intramedullary chondrosarcoma of extremities.

AIM: Clinical diagnosis and surgical treatment of chondrosarcoma (CS) are continuously improving. The purpose of our study is to evaluate the effectiveness of microwave ablation (MWA) assisted degradation therapy in the surgical treatment of intramedullary chondrosarcoma of the extremities, to provide a new reference and research basis for the surgical treatment of CS. METHODS: We recruited 36 patients with intramedullary CS who underwent MWA assisted extended curettage. Preoperative patient demographics and clinical data were recorded. Surgery was independently assisted by a medical team. Patients were followed up strictly and evaluated for oncological prognosis, radiological results, limb joint function, pain, and complications. RESULTS: We included 15 men and 21 women (mean age: 43.5 ± 10.1). The average length of the lesion was 8.1 ± 2.5 cm. Based on preoperative radiographic, clinical manifestations, and pathological results of puncture biopsy, 28 patients were preliminarily diagnosed with CS-grade I and eight patients with CS-grade II. No recurrence or metastasis occurred in the postoperative follow-up. The average Musculoskeletal Tumor Society score was 28.8 ± 1.0, significantly better than presurgery. Secondary shoulder periarthritis and abduction dysfunction occurred in early postoperative stage CS of the proximal humerus in some, but returned to normal after rehabilitation exercise. Secondary bursitis occurred at the knee joint in some due to the internal fixation device used in treatment; however, secondary osteoarthritis and avascular necrosis of the femoral head were not observed. Overall, oncological and functional prognoses were satisfactory. CONCLUSIONS: The application of MWA assisted degradation therapy in intramedullary CS can achieve satisfactory oncology and functional prognosis, providing a new option for the limited treatment of CS.

Changes in thyroid hormones predict weight regain in patients with obesity who undergo metabolic surgery.

AIM: To investigate the relationship between thyroid function and weight regain in patients with obesity after metabolic surgery. METHODS: This retrospective study enrolled 162 patients who underwent metabolic surgery. Correlations between decreases in thyroid hormone levels and changes in weight, waist circumference (WC) and the Chinese visceral adiposity index (CVAI) were assessed. Binary logistic regression and receiver operating characteristic (ROC) curves were used to identify predictors and clinically useful cut-off values, respectively. RESULTS: The levels of thyroid-stimulating hormone (TSH) and free triiodothyronine (FT3) decreased markedly at 1 year after surgery, as did weight, body mass index (BMI), triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, WC and CVAI. Decreases in TSH and FT3 after metabolic surgery were associated with changes in weight, BMI and CVAI. Binary logistic regression and ROC curve analyses confirmed that decreases in TSH can predict good weight loss after metabolic surgery to some extent. Finally, binary logistic regression and ROC curve analyses confirmed that changes in TSH can predict weight regain after metabolic surgery. CONCLUSIONS: Changes in TSH and FT3 after metabolic surgery were correlated with changes in weight and CVAI. Changes in thyroid hormones can predict weight regain in patients with obesity who underwent metabolic surgery.

Efficacy and safety of venetoclax-based combination therapy for previously untreated acute myeloid leukemia: a meta-analysis.

PURPOSE: To explore the efficacy and safety of venetoclax-based combination therapy for older patients with newly diagnosed acute myeloid leukemia (AML). METHODS: We performed a systematic review and meta-analysis of clinical trials comparing venetoclax plus hypomethylating agents (HMAs) or low-dose cytarabine (LDAC) with mono-HMAs or LDAC. The random or fixed effects model was applied to the studies based on heterogeneity. Dichotomous data were summarized using the risk ratio (RR) and 95% confidence interval (CI). Continuous variable data were reported as weighted mean differences (WMDs). RESULTS: Nine studies, including a total of 1232 patients, were included in this meta-analysis. Thec complete remission (CR)/complete remission with incomplete hematological recovery (CRi) rate of the venetoclax (Ven) + azacytidine (Aza) group was significantly greater than that of the Aza monotherapy group (RR: 2.42; 95% CI: 1.85-3.15; P < 0.001). Similarly, the CR/CRi rate of the Ven + LDAC group was also significantly greater than that of the LDAC monotherapy group (RR: 2.57; 95% CI: 1.58-4.17; P = 0.00). The same results were observed for OS among these groups. However, the incidence of febrile neutropenia was greater in the Ven + Aza group than in the Ven + Decitabine (Dec) or monotherapy Aza group (RR: 0.69; 95% CI: 0.53-0.90; P = 0.006 and RR: 2.19; 95% CI: 1.58-3.03; P < 0.001, respectively). In addition, the Ven + LDAC group had significantly greater rates of constipation, diarrhea, nausea, and vomiting than the LDAC monotherapy group, with RRs and CIs of 0.61 (95% CI 0.44-0.83, P = 0.002), 1.81 (95% CI 1.22-2.67, P = 0.003), 1.39 (95% CI 1.06-1.82, P = 0.016), and 1.80 (95% CI 1.19-2.72, P = 0.005), respectively. CONCLUSION: Venetoclax combined with azacitidine, decitabine, or LDAC significantly improved the CR/CRi and OS of patients with previously untreated AML. However, venetoclax plus azacitidine or LDAC was more likely to lead to increased febrile neutropenia and gastrointestinal toxicity.

Borderline personality traits mediate the relationship between negative life events and nonsuicidal self-injury in a clinical sample with youth depression.

BACKGROUND: Borderline personality traits play a significant role in nonsuicidal self-injury (NSSI), particularly in depressed youths. NSSI is also highly correlated with negative life events. This research aimed to explore the connections between negative life events, borderline personality traits, and NSSI. METHODS: The study included 338 depressed youth aged 13 to 25 years. Self-reported measures and clinical interviews were utilized to evaluate the depressive symptoms, borderline personality traits, negative life events, and NSSI behaviours of these participants. Identifying variables linked to NSSI was the aim of our analysis, and we also conducted a mediation analysis to look into the influence of borderline traits on the connection between negative life events and NSSI. RESULTS: Of the 338 depressed youth, approximately 59.47% (201/338) displayed NSSI, which was associated with greater clinical severity. Borderline traits had an independent influence on NSSI and it partially explained the connection between negative life events and NSSI, even when accounting for depression symptoms. Depressed youth who were more vulnerable to NSSI behaviours often experienced negative life events such as interpersonal relationships, academic pressure, being punished, and loss. CONCLUSIONS: Our research suggests that depressed youth who experience more negative life events are more likely to experience NSSI, and negative life events indirectly influence nonsuicidal self-injury through borderline personality traits. Implementing interventions focused on mitigating borderline symptoms could be a promising therapeutic approach for addressing NSSI in young people.

A Polarization-Insensitive, Vanadium Dioxide-Based Dynamically Tunable Multiband Terahertz Metamaterial Absorber.

A tunable multiband terahertz metamaterial absorber, based on vanadium dioxide (VO2), is demonstrated. The absorber comprises a three-layer metal-insulator-metal (MIM) configuration with a split ring and slots of VO2 on the uppermost layer, a middle dielectric substrate based on silicon dioxide (SiO2), and a gold reflector on the back. The simulation results indicate that, when VO2 is in the metallic state, the proposed metamaterial exhibits nearly perfect absorption at six distinct frequencies. The design achieves an average absorption of 98.2%. The absorptivity of the metamaterial can be dynamically tuned from 4% to 100% by varying the temperature-controlled conductivity of VO2. The proposed metamaterial absorber exhibits the advantages of polarization insensitivity and maintains its absorption over 80% under different incident angle conditions. The underlying physical mechanism of absorption is explained through impedance matching theory, interference theory, and the distribution of electric fields. The ability to achieve multiband absorption with tunable characteristics makes the proposed absorber a promising candidate for applications in terahertz sensing, imaging, communication, and detection. The polarization insensitivity further enhances its practicality in various scenarios, allowing for versatile and reliable performance in terahertz systems.

Longitudinal changes in body mass index, height, and weight in children with acute myeloid leukemia.

BACKGROUND: This study reported height prediction and longitudinal growth changes in Chinese pediatric patients with acute myeloid leukemia (AML) during and after treatment and their associations with outcomes. METHODS: Changes in 88 children with AML in percentages according to the growth percentile curve for Chinese boys/girls aged 2-18/0-2 years for body mass index (BMI), height, and weight from the time of diagnosis to 2 years off therapy were evaluated. The outcomes of AML were compared among patients with different BMI levels. RESULTS: The proportion of underweight children (weight < 5th percentile) increased significantly from the initial diagnosis to the end of consolidation treatment. The proportion of patients with low BMI (BMI < 5th percentile) was highest (23.08%) during the consolidation phase, and no children were underweight, but 20% were overweight (BMI > 75th percentile) after 2 years of drug withdrawal. Unhealthy BMI at the initial diagnosis and during intensive chemotherapy leads to poorer outcomes. For height, all patients were in the range of genetic height predicted based on their parents' height at final follow-up. CONCLUSIONS: Physicians should pay more attention to the changes in height and weight of children with AML at these crucial treatment stages and intervene in time.

Step count and multiple health outcomes: An umbrella review.

OBJECTIVE: This study aimed to quantify the association between step count and multiple health outcomes in a healthy population. METHODS: PubMed, Embase, Web of Science, and The Cochrane Library were systematically searched for systematic reviews and meta-analyses from inception to April 1, 2022. Literature screening, data extraction, and data analysis were performed in this umbrella review. The intervention factor was daily step counts measured based on devices. Multiple health outcomes included metabolic diseases, cardiovascular diseases, all-cause mortality, and other outcomes in the healthy population. RESULTS: Twenty studies with 94 outcomes were identified in this umbrella review. The increase in daily step count contributed to a range of human health outcomes. Furthermore, the special population, different age groups, countries, and cohorts should be carefully considered. Negative correlation between step counts and the following outcomes: metabolic outcomes, cardiovascular diseases, all-cause mortality, postural balance, cognitive function, and mental health. However, there was no association between participation in the outdoor walking group and the improvement of systolic blood pressure and diastolic blood pressure. Analysis of the dose-response association between increasing daily step count and the risk of cardiovascular disease events and all-cause mortality showed a substantially linear relationship. CONCLUSION: A wide range of health outcomes can benefit from the right number of steps.

Thermal stability of triple-junction gallium arsenide cells.

Laser wireless power transmission (LWPT) systems have significant applications in the field of wireless energy transmission, including spacecraft sensor networks, satellite-to-satellite communication, and remote power supply. However, continuous laser exposure increases the temperature of the photovoltaic (PV) cells in the LWPT system, thus decreasing the electrical output performance. This work, which we believe is a new approach, is on the basis of a notch film designed by a combined merit function proposed to maintain the electrical output performance while under 1064-nm continuous laser irradiation. Moreover, the thermal stability of PV cells under laser irradiation was investigated, which revealed the recoverability of the open-circuit voltage (Voc) of the cells at different temperatures, and the thermal damage to cells was a gradual process. This process began with the vaporization of the encapsulation adhesive, followed by a decline in, but still recoverable and functional, electrical performance, and finally, the cell was completely damaged. The thermal stability of the PV cells coated with the notch film increased ten-fold compared to those without it. Furthermore, the correlation between the minimum Voc and maximum temperature of the cells with notch films of different performances was established. These investigations serve as references for further optimization of LWPT.

Sleep disturbance and suicidal ideation among youth with depression.

BACKGROUND: Sleep disturbance may exacerbate the risk of suicide among youth with depression, but whether this association is independent of psychopathology requires further study. METHODS: This cross-sectional study included 576 youths (13-25 years old) recruited from January 2022 to May 2023. The patients were first divided into two groups by the presence of suicidal ideation according to the Columbia-Suicide Severity Scale (C-SSRS). Sleep quality was assessed by the Athens Insomnia Scale (AIS) and mental health with the Hamilton Depression Rating Scale (HAMD) and Hamilton Anxiety Rating Scale (HAMA). Logistic regression was conducted to analyze the association between sleep disturbance and suicidal ideation, adjusted for depressive symptoms severity. RESULTS: The suicidal ideation group exhibited more severe sleep disturbances, anxiety symptoms, and depressive symptoms than the non-suicidal ideation group. Pearson correlation showed that sleep disturbance (AIS) was significantly correlated with the severity of anxiety symptoms, depressive symptoms, and suicidal ideation. Logistic regression analysis revealed that the AIS factor "daytime dysfunction" (ß = 0.145; OR = 1.156, 95 % CI: 1.02, 1.309; p = 0.023) was significantly associated with suicidal ideation after adjusting for demographic characteristics and depressive symptoms severity. LIMITATIONS: Due to the cross-sectional nature of the data, no causal inference can be made regarding the observed associations between sleep disturbance and suicidal ideation. CONCLUSION: Sleep disturbance, particularly in the realm of daytime dysfunction, is associated with increased suicidal ideation among depressed youth. Clinicians need to assess and manage sleep disturbance in the context of suicidal ideation for young depression patients.

Integrative transcriptome analysis identifies MYBL2 as a poor prognosis marker for osteosarcoma and a pan-cancer marker of immune infiltration.

MYBL2 (MYB proto-oncogene like 2) is an emerging prognostic marker for malignant tumors, and its potential role in osteosarcoma and its relationship with immune infiltration in pan-cancer is yet to be elucidated. We constructed a transcription factor activity profile of osteosarcoma using the single-cell regulatory network inference algorithm based on single-cell RNA sequencing data obtained from the Gene Expression Omnibus. Subsequently, we calculated the extent of MYBL2 activation in malignant proliferative osteoblasts. We also explored the association between MYBL2 and chemotherapy resistance in osteosarcoma. Furthermore, we systematically correlated MYBL2 with immunological signatures in the tumor microenvironment in pan-cancer, including immune cell infiltration, immune checkpoints, and tumor immunotherapy prognosis. Finally, we developed and validated a risk score (MRGS), derived an osteosarcoma risk score nomogram based on MRGS, and tested its ability to predict prognosis. MYBL2 and gene enrichment analyses in osteosarcoma and pan-cancer revealed that MYBL2 was positively correlated with cell proliferation and tumor immune pathways. MYBL2 expression positively correlated with SLC19A1 in pan-cancer and osteosarcoma cell lines. Pan-cancer immune infiltration analysis revealed that MYBL2 was correlated with myeloid-derived suppressor cells, Th2 cell infiltration, CD276, RELT gene expression, and tumor mutation burden. In summary, MYBL2 regulates proliferation, progression, and immune infiltration in osteosarcoma and pan-cancer. Therefore, we found that MYBL2 could be used as a potential marker for predicting the osteosarcoma prognosis. Patients with osteosarcoma and high MYBL2 expression are theoretically more sensitive to methotrexate. An osteosarcoma prognostic nomogram can provide new ideas in the search for osteosarcoma prognostic markers.

High leaching potential combined with a low leaching amount of fertilizer-derived nitrate in conservation tillage cropland of Northeast China.

Stover mulching in no-tillage farming has been widely proposed as an optimized agricultural management practice to increase soil carbon storage and improve fertilizer nitrogen (N) use efficiency in current agroecosystems. However, the regulation of soil internal gross N transformation dynamics on NO3--N leaching potential in response to long-term conservation tillage practices is still lacking. Here, based on a combination of 15N-tracing incubation and in situ monitoring experiments, we investigated the effect of 9-year no-tillage and maize stover mulching on the vertical migration of fertilizer-derived NO3--N into a deeper soil profile and the associated gross NO3--N transformation dynamics in the Mollisol of Northeast China. The net positive NO3--N production rates (varied from 3.14 to 6.22 mg N kg-1 d-1) were observed across all management practices in the studied Mollisol, indicating a relatively high NO3--N leaching potential in the cropland of Northeast China, which was further confirmed by an average of 7.4 % fertilizer-derived NO3--N being vertically transferred to the 80-100 cm soil layer after a complete maize growing period. Compared with traditional ridge tillage, long-term stover mulching in no-tillage farming significantly reduced total NO3--N production by decreasing autotrophic nitrification while simultaneously enhancing total NO3--N consumption by stimulating nitrate reduction and microbial NO3--N immobilization, revealing a markedly reduction of net NO3--N production in the no-tillage agroecosystem. Therefore, converting traditional ridge tillage toward no-tillage with maize stover mulching can effectively decrease fertilizer-derived NO3--N leaching amounts and thus formulate targeted mitigation strategies for sustainable agriculture in Mollisols of Northeast China.

Synthetic Ligament-Assisted Functional Soft-Tissue Reconstruction in Tumor-Related Proximal Femoral Replacements.

BACKGROUND: Soft-tissue functional reconstruction is important for restoring hip function in proximal femoral replacement for tumor resection. This study evaluated the functional outcome and postoperative complications of a specific synthetic ligament for soft-tissue functional reconstruction in proximal femoral replacement for tumor resection. METHODS: This cohort included 80 patients (40 men and 40 women, mean age, 40 years (range, 10 to 79)) who had benign invasive tumors (n = 13), primary malignant bone tumors (n = 40), or bone metastases (n = 27). Patients' medical records, imaging files, surgical details, and postoperative pathological diagnoses were collected. Tumor staging was performed with the Enneking staging criteria. Lower limb and hip functions were assessed using the Musculoskeletal Tumor Society scoring system and Harris Hip score, respectively. RESULTS: Mean postoperative Musculoskeletal Tumor Society and Harris Hip scores were 27 (range, 24 to 30) and 90 (range, 76 to 97), respectively, indicating satisfactory range of motion and stability. Trendelenburg gait was observed in 3 osteosarcoma patients (3.8%), and 6 patients showed unequal lower-limb lengths. Reoperations occurred in 5 cases, including 3 cases of deep vein thromboses and 1 case each of giant cell granuloma and periprosthetic infection. There were 27 patients who had bone metastases who did not require reoperation. CONCLUSIONS: The synthetic ligament reconstruction of the hip with proximal femoral replacement for tumor resection was associated with improved outcomes. Its implementation exhibits the potential to reduce postoperative incidences of hip dislocation and periprostheses infection, thereby warranting its prospective clinical application.

Prevalence and correlates of suicide risk among non-psychiatric inpatients in a general hospital in China.

OBJECTIVE: This study aims to investigate the suicide risk and mental health status of non-psychiatric inpatients in general hospital and explore the risk factors of suicide. METHODS: A prospective study was conducted at a tertiary general hospital in Guangzhou, Guangdong Province, China. On-line assessment of mental health status and suicide was completed at admission and discharge. We assessed depression, anxiety, insomnia and suicide of inpatients and binary logistics regression was used to examine the risk factors of suicide. RESULTS: From April 1, 2021 and January 31, 2022, 3685 inpatients were included. The detection rates of depression, anxiety and insomnia were 14.6 %, 9.0 % and 17.8 %, respectively. There were 2.7 % of inpatients at suicide risk. Binary logistics regression demonstrated that the inpatients with anxiety were at higher risk of suicide. LIMITATIONS: (1) Single-center study limits the generalization of conclusion, (2) low response rate at discharge. CONCLUSIONS: The comorbidity of physical illnesses and mental health problems, including depression, anxiety, insomnia, and suicide among non-psychiatric patients in general hospital was common. An assessment of anxiety may help identify individuals at high suicide risk. Medical staff in general hospitals should be trained to improve their ability to identify mental disorders and high-risk individuals for suicide, provide timely interventions and effectively reduce the suicide risk of patients.

Proteomic analysis of aqueous humor reveals novel regulators of diabetic macular edema.

Diabetic macular edema (DME) is the most common cause of blindness in patients with diabetic retinopathy. To investigate the proteomic profiles of the aqueous humor (AH) of individuals with diabetic macular edema (DME), AH samples were collected from patients with non-diabetes mellitus (NDM), DM, nonproliferative diabetic retinopathy (NPDR), and DME. We performed comparative proteomic analyses using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and bioinformatics analyses. We identified 425 proteins in these AH samples, of which 113 showed changes in expression in DME compared with NDM, 95 showed changes in expression in DME vs. DM, and 84 showed changes in expression in DME compared with NPDR. The bioinformatics analysis suggested that DME is closely associated with platelet degranulation, oxidative stress-related pathway, and vascular-related pathways. Upregulation of haptoglobin (HP) and downregulation of fibrillin 1 (FBN1) were validated by ELISA. Receiver operating characteristic (ROC) analysis showed that HP and FBN1 could distinguish DME from NPDR with areas under the curve of 0.987 (p = 0.00608) and 0.791 (p = 0.00629), respectively. The findings provide potential clues for further analysis of the molecular mechanisms and the development of new treatments for DME. HP and FBN1 may be potential key proteins and therapeutic targets in human DME. The proteomics dataset generated has been deposited to the ProteomeXchange/iProX Consortium with Identifier: PXD033404/IPX0004353001.

Acute ketamine induces neuronal hyperexcitability and deficits in prepulse inhibition by upregulating IL-6.

Acute ketamine administration results in psychotic symptoms similar to those observed in schizophrenia and is regarded as a pharmacological model of schizophrenia. Accumulating evidence suggests that patients with schizophrenia show increased IL-6 levels in the blood and cerebrospinal fluid and that IL-6 levels are associated with the severity of psychotic symptoms. In the present study, we found that a single ketamine exposure led to increased expression of IL-6 and IL-6Rα, decreased dendritic spine density, increased expression and currents of T-type calcium channels, and increased neuron excitability in the hippocampal CA1 area 12 h after exposure. Acute ketamine administration also led to impaired prepulse inhibition (PPI) 12 h after administration. Additionally, we found that the expression of signaling molecules IKKα/ß, NF-κB, JAK2, and STAT3 was upregulated 12 h after a single ketamine injection. The decreases in dendritic spine density, the increases in calcium currents and neuron excitability, and the impairments in PPI were ameliorated by blocking IL-6 or IL-6Rα. Our findings show that blocking IL-6 or its receptor may protect hippocampal neurons from hyperexcitability, thereby ameliorating ketamine-induced psychotic effects. Our study provides additional evidence that targeting IL-6 and its receptor is a potential strategy for treating psychotic symptoms in acute ketamine-induced psychosis and schizophrenia.

Glucose metabolism disorder: a potential accomplice of SARS-CoV-2.

Globally, 265,713,467 confirmed cases of SARS-CoV-2 (CoV-2), including 5,260,888 deaths, have been reported by the WHO. It is important to study the mechanism of this infectious disease. A variety of evidences show the potential association between CoV-2 and glucose metabolism. Notably, people with type 2 diabetes mellitus (T2DM) and other metabolic complications were prone to have a higher risk of developing a more severe infection course than people who were metabolically normal. The correlations between glucose metabolism and CoV-2 progression have been widely revealed. This review will discuss the association between glucose metabolism disorders and CoV-2 progression, showing the promoting effect of diabetes and other diseases related to glucose metabolism disorders on the progression of CoV-2. We will further conclude the effects of key proteins and pathways in glucose metabolism regulation on CoV-2 progression and potential interventions by targeting glucose metabolism disorders for CoV-2 treatment. Therefore, this review will provide systematic insight into the treatment of CoV-2 from the perspective of glucose metabolism.

Ultra-broad bandwidth low-dispersion mirror with smooth dispersion and high laser damage resistance.

Low-dispersion mirrors (LDMs), which require a broad bandwidth, low dispersion, and high damage threshold, are essential optics in ultra-intense and ultra-short laser devices. Bragg mirrors and chirped LDMs do not satisfy these requirements simultaneously. We propose a novel LDM (NLDM) based on the hump-like structure and quarter wavelength optical thickness (QWOT) structure to achieve a broad bandwidth, smooth dispersion, and high robustness. The spectral and dispersion characteristics of the two structures compensate for each other, which makes up for the deficiency that the dispersion bandwidth of the sinusoidal modulation structure cannot be broadened. Based on this structure, the LDM can achieve a design bandwidth of 240 nm and support the transmission of sub-11-fs pulses. The accuracy of the NLDM is experimentally evaluated. The structure shows the potential for broad-spectrum laser damage performance due to the low electric field intensity. The NLDM improves the mirror performance and paves the way for a new generation of ultra-intense and ultra-short laser devices.

Biological reconstruction of bone defect after resection of malignant bone tumor by allograft: a single-center retrospective cohort study.

BACKGROUND: Allograft reconstruction following the resection of malignant bone tumors is associated with high rates of complications and failures. This study aimed to evaluate the efficacy and current problems of allograft reconstruction techniques to optimize treatment strategies at our center. MATERIALS AND METHODS: Thirty-eight cases (16 men and 22 women), who were diagnosed with malignant bone tumors and had undergone allograft reconstruction, were recruited. Allograft was fixed by intramedullary nail, single steel plate, double plate, and intramedullary nail combined plate in 2, 4, 17, and 15 cases, respectively. Allograft union, local recurrence, and complications were assessed with clinical and radiological tests. Tumor grade was assessed using the Enneking staging of malignant bone tumors. Functional prognosis was evaluated by the Musculoskeletal Tumor Society (MSTS) scoring system. RESULTS: Intercalary and osteoarticular reconstructions were performed in 32 and 6 cases, respectively. Six patients underwent reoperation related to allograft complications, four patients had local recurrence, and three patients with allograft fracture underwent allograft removal. A total of eight host-donor junctions showed nonunion, including seven cases (18.4%) in diaphysis and one case (3.1%) in metaphysis (p < 0.01). Host rejection and secondary osteoarthritis occurred in nine and two cases, respectively. No deep infection and internal fixation device fracture occurred. The overall allograft survival rate was 81.6%. Postoperative MSTS score of patients with allograft survival was 26.8 ± 2.9, indicating a significant improvement as compared to their preoperative function. CONCLUSIONS: Allograft represents an excellent choice for intercalary bone defects after malignant bone tumor resection. Robust internal fixation protection across the whole length of the allograft is an important prerequisite for the survival of the allograft, while multidimensional osteotomy, intramedullary cement reinforcement, and pedicled muscle flap transfer can effectively improve the survival rate and healing rate of the allograft.

Mechanisms of conservation tillage on nitrogen-fertilizer reduction and maize grain improvement in Mollisols of Northeast China: Insights from a 15N tracing study.

Conservation tillage is an important management practice to guarantee soil fertility in degraded Mollisols. It is still unclear, however, whether the improvement and stability of crop yield under conservation tillage can be sustainable with increasing soil fertility and reducing fertilizer-N application. Based on a long-term tillage experiment initiated in Lishu Conservation Tillage Research and Development Station by Chinese Academy of Sciences, we conducted a 15N tracing field micro-plot experiment to investigate the effects of reducing nitrogen application on maize yield and fertilizer-N transformation under long-term conservation tillage agroecosystem. There were four treatments, including conventional ridge tillage (RT), no-tillage with 0% (NT0), 100% (NTS) maize straw mul-ching, and 20% reduced fertilizer-N plus 100% maize stover mulching (RNTS). The results showed that after a complete cultivation round, the average percentages of fertilizer N recovery in soil residues, crop usage, and gaseous loss were 34%, 50%, and 16%, respectively. Compared with conventional ridge tillage, no-tillage with maize straw mulching (NTS and RNTS) significantly increased the use efficiency of fertilizer N in current season by 10% to 14%. From the perspective of N sourcing analysis, the average percentage of fertilizer N absorbed by crop parts (including seeds, straws, roots, and cobs) to the total N uptake reached nearly 40%, indicating that soil N pool was the main source of N for crop uptakes. In comparison with conventional ridge tillage, conservation tillage significantly increased total N storage in 0-40 cm by reducing soil disturbance and increasing organic inputs, and thus ensured the expansion and efficiency increment of soil N pool in degraded Mollisols. Compared with conventional ridge tillage, NTS and RNTS treatments significantly increased the maize yield from 2016 to 2018. In all, by improving fertilizer nitrogen utilization efficiency and maintaining the continuous supply of soil nitrogen, long-term management of no-tillage with maize straw mulching could achieve a stable and increasing maize yield in three consecutive growing seasons and simultaneously reduce environmental risks derived by fertilizer-N losses, even under the condition of 20% reduction of fertilizer-N application, and thus actualize the sustainable development of agriculture in Mollisols of Northeast China.