Myosteatosis is associated with coronary artery calcification in patients with type 2 diabetes

BACKGROUND Myosteatosis,rather than low muscle mass,is the primary etiologic factor of sarcopenia in patients with type 2 diabetes mellitus(T2DM).Myosteatosis may lead to a series of metabolic dysfunctions,such as insulin resistance,systematic inflammation,and oxidative stress,and all these dysfunctions are closely associated with the acceleration of T2DM and atherosclerosis.AIM To investigate the association between myosteatosis and coronary artery calcification(CAC)in patients with T2DM.METHODS Patients with T2DM,who had not experienced major cardiovascular events and had undergone both abdominal and thoracic computed tomography(CT)scans,were included.The mean skeletal muscle attenuation was assessed using abdominal CT images at the L3 level.The CAC score was determined from thoracic CT images using the Agatston scoring method.Myosteatosis was diagnosed according to Martin’s criteria.Severe CAC(SCAC)was defined when the CAC score exceeded 300.Logistic regression and decision tree analyses were performed.RESULTS A total of 652 patients with T2DM were enrolled.Among them,167(25.6%)patients had SCAC.Logistic regression analysis demonstrated that myosteatosis,age,duration of diabetes,cigarette smoking,and alcohol consumption were independent risk factors of SCAC.Myosteatosis was significantly associated with an increased risk of SCAC(OR=2.381,P=0.003).The association between myosteatosis and SCAC was significant in the younger patients(OR=2.672,95%CI:1.477-4.834,P=0.002),but not the older patients(OR=1.456,95%CI:0.863-2.455,P=0.188),and was more prominent in the population with lower risks of atherosclerosis.The decision tree analyses prioritized older age as the primary variable for SCAC.In older patients,cigarette smoking was the main contributing factor for SCAC,while in younger patients,it was myosteatosis.CONCLUSION Myosteatosis is a novel risk factor for atherosclerosis in patients with T2DM,especially in the population with younger ages and fewer traditional risk factors.

Animal Model of Aortic Valve Calcification: Their Methodology Helps Us Understand Aortic Valve Calcification

Aortic valve calcification disease (CAVD) is the most prevalent degenerative valve disease in humans, leading to significant morbidity and mortality. Despite its common occurrence, our understanding of the underlying mechanisms remains incomplete, and available treatment options are limited and risky. A more comprehensive understanding of the biology of CAVD is essential to identify new therapeutic strategies. Animal models have played a crucial role in advancing our knowledge of CAVD and exploring potential treatments. However, these models have inherent limitations as they cannot fully replicate the complex physiological mechanisms of human CAVD. In this review, we examine various CAVD models ranging from pigs to mice, highlighting the unique characteristics of each model to enhance our understanding of CAVD. While these models offer valuable insights, they also have limitations and shortcomings. We propose that the guide wire model shows promise for future CAVD research, and streamlining the methodology could enhance our understanding and expand the research scope in this field.

Animal models of tendon calcification:Past,present,and future

Tendon calcification is a common clinical condition that frequently occurs as a complication after tendon injury and surgery,or as an expression of fibrodysplasia ossificans progressiva.This condition can be referred to by various names in clinical practice and literature,including tendon ossification,tendon mineralization,heterotopic ossification,and calcific tendonitis.The exact pathogenesis of tendon calcification remains uncertain,but current mainstream research suggests that calcification is mostly cell mediated.To further elucidate the pathogenesis of tendon calcification and to better simulate the overall process,selecting appropriate experimental animal models is important.Numerous animal models have been utilized in various clinical studies,each with its own set of advantages and limitations.In this review,we have discussed the advancements made in research on animal models of tendon calcification,with a focus on the selection of experimental animals,the sites of injury in these models,and the methods employed for modeling.

Asymmetric expression of CA2 and CA13 linked to calcification in the bilateral mandibular condyles cause crossed beaks in chickens

Crossed beak is a complex mode of inheritance with prevalence ranging from 0.2 to 7.4% in at least 12 chicken strains worldwide.To reveal the intrinsic factors causing crossed beaks,genes expression patterns in bilateral mandibular condyle between affected and normal birds were characterized by RNA sequencing analysis in the present studies.Crossed beak was induced by short length of unilateral mandibular ramus,and a total of 110differentially expressed genes were up-or down-regulated in the affected(short)mandibular condyle side as compared to the normal side.Carbonic anhydrase 2(CA2)and Carbonic anhydrase 13(CA13)were enriched in the carbonate dehydratase activity,and high-expressed in mandibular condyle and osteoblasts(P<0.05).However,both were low-expressed in short mandibular condyle side of affected birds(P<0.05).The carbonate dehydratase inhibitor experiments confirmed that there is positive association between the calcification and carbonic anhydrase isoenzymes.Quantitative analysis with cetylpyridinium chloride showed a decrease in calcification when the cells were transfected with an anti-CA13 shRNA.Our research suggested that CA2 and CA13 are down-calcified in shortside mandibular condyle,and caused mandibular ramus to grow slowly.CA2 and CA13 have the critical role in crossed beaks by regulating calcification of mandibular condyle.

Vascular Calcification:Where is the Cure?

With the progress of aging,the incidence of vascular calcification(VC)gradually increases,which is correlated with cardiovascular events and all-cause death,aggravating global clinical burden.Over the past several decades,accumulating approaches targeting the underlying pathogenesis of VC have provided some possibilities for the treatment of VC.Unfortunately,none of the current interventions have achieved clinical effectiveness on reversing or curing VC.The purpose of this review is to make a summary of novel perspectives on the interventions of VC and provide reference for clinical decision-making.

Calcification-associated molecular traits and therapeutic strategies in hormone receptor-positive HER2-negative breast cancer

Objective:Mammographic calcifications are a common feature of breast cancer,but their molecular characteristics and treatment implications in hormone receptor-positive(HR+)/human epidermal growth factor receptor 2-negative(HER2−)breast cancer remain unclear.Methods:We retrospectively collected mammography records of an HR+/HER2−breast cancer cohort(n=316)with matched clinicopathological,genomic,transcriptomic,and metabolomic data.On the basis of mammographic images,we grouped tumors by calcification status into calcification-negative tumors,tumors with probably benign calcifications,tumors with calcification of lowmoderate suspicion for maligancy and tumors with calcification of high suspicion for maligancy.We then explored the molecular characteristics associated with each calcification status across multiple dimensions.Results:Among the different statuses,tumors with probably benign calcifications exhibited elevated hormone receptor immunohistochemical staining scores,estrogen receptor(ER)pathway activation,lipid metabolism,and sensitivity to endocrine therapy.Tumors with calcifications of high suspicion for malignancy had relatively larger tumor sizes,elevated lymph node metastasis incidence,Ki-67 staining scores,genomic instability,cell cycle pathway activation,and may benefit from cyclin-dependent kinase 4 and 6(CDK4/6)inhibitors.Conclusions:Our research established links between tumor calcifications and molecular features,thus proposing potential precision treatment strategies for HR+/HER2−breast cancer.

Enhanced Wolf Pack Algorithm (EWPA) and Dense-kUNet Segmentation for Arterial Calcifications in Mammograms

Breast Arterial Calcification(BAC)is a mammographic decision dissimilar to cancer and commonly observed in elderly women.Thus identifying BAC could provide an expense,and be inaccurate.Recently Deep Learning(DL)methods have been introduced for automatic BAC detection and quantification with increased accuracy.Previously,classification with deep learning had reached higher efficiency,but designing the structure of DL proved to be an extremely challenging task due to overfitting models.It also is not able to capture the patterns and irregularities presented in the images.To solve the overfitting problem,an optimal feature set has been formed by Enhanced Wolf Pack Algorithm(EWPA),and their irregularities are identified by Dense-kUNet segmentation.In this paper,Dense-kUNet for segmentation and optimal feature has been introduced for classification(severe,mild,light)that integrates DenseUNet and kU-Net.Longer bound links exist among adjacent modules,allowing relatively rough data to be sent to the following component and assisting the system in finding higher qualities.The major contribution of the work is to design the best features selected by Enhanced Wolf Pack Algorithm(EWPA),and Modified Support Vector Machine(MSVM)based learning for classification.k-Dense-UNet is introduced which combines the procedure of Dense-UNet and kU-Net for image segmentation.Longer bound associations occur among nearby sections,allowing relatively granular data to be sent to the next subsystem and benefiting the system in recognizing smaller characteristics.The proposed techniques and the performance are tested using several types of analysis techniques 826 filled digitized mammography.The proposed method achieved the highest precision,recall,F-measure,and accuracy of 84.4333%,84.5333%,84.4833%,and 86.8667%when compared to other methods on the Digital Database for Screening Mammography(DDSM).

Giant cavernous aneurysms occluded by aneurysmal thrombosis,calcification,parent artery occlusion:A case report and review of literature

BACKGROUND Patients with giant intracranial aneurysms(GIAs)are at a high risk of rupture,morbidity,and mortality even after surgical or endovascular treatment.We described a case of a spontaneously occluded GIA secondary to gradual growth of the GIA,continuously progressed aneurysmal thrombosis,complete aneurysmal calcification and complete occlusion of the parent artery-the right internal carotid artery(RICA).CASE SUMMARY A 72-year-old female patient complained of sudden pain in her right eye upon admission to our hospital.She had been diagnosed with a GIA[30 mm(axial)×38 mm(coronal)×28 mm(sagittal)]containing an aneurysmal thrombus located in the cavernous sinus segment of RICA diagnosed by magnetic resonance imaging(MRI),enhanced MRI,and magnetic resonance angiography more than 14 years ago.Later,with slow growth of the cavernous carotid GIA,aneurysmal thrombosis progressed continuously,spontaneous occlusion of the RICA,complete aneurysmal calcification,and occlusion of the GIA occurred gradually.She had no history of subarachnoid hemorrhage but missed the chance for endovascular therapy at an early stage.As a result,she was left with severe permanent sequelae from the injuries to the right cranial nerves Ⅱ,Ⅲ,Ⅳ,V1/V2,and Ⅴ.CONCLUSION The risk of rupture of the cavernous carotid GIAs was relatively low and possibly further be reduced by the stasis flow and spontaneous occlusion of the parent artery internal carotid artery(ICA)induced by the mass effect of the cavernous carotid GIAs and the extremely rare aneurysmal calcification.However,nowadays,it is advisable to recommend early endovascular treatment for the cavernous carotid GIAs to prevent injuries to the surrounding intracranial nerves and occlusion of the ICA,mainly caused by the mass effect of the cavernous carotid GIAs.

Potential efficacy and mechanism of medicinal plants on chronic kidney disease-associated vascular calcification:a review

Vascular calcification is a crucial risk factor that affects the incidence and mortality of cardiovascular disease in chronic kidney disease patients.Modern medicine relies on calcium-phosphorus binding agents,calcium mimetics,active vitamin D,and hemodialysis to prevent and treat vascular calcification,however,their efficacy is unsatisfactory and adverse reactions often occur.Medical plant therapy can act as an integrative regulator in patients with chronic kidney disease-associated vascular calcification,which can significantly improve patients’symptoms,but its specific mechanism has not been fully elucidated yet.In this paper,we reviewed the domestic and international theoretical studies on the pathogenesis mechanism of chronic kidney disease-associated vascular calcification in recent years,summarized eight active ingredients of medicinal plants as well as four compound formulas for improving chronic kidney disease-associated vascular calcification,and explored the mechanism of action of herbal medicine,which will provide a new strategy for promoting the prevention and treatment of vascular calcification.

Integrating Transformer and Bidirectional Long Short-Term Memory for Intelligent Breast Cancer Detection from Histopathology Biopsy Images

Breast cancer is a significant threat to the global population,affecting not only women but also a threat to the entire population.With recent advancements in digital pathology,Eosin and hematoxylin images provide enhanced clarity in examiningmicroscopic features of breast tissues based on their staining properties.Early cancer detection facilitates the quickening of the therapeutic process,thereby increasing survival rates.The analysis made by medical professionals,especially pathologists,is time-consuming and challenging,and there arises a need for automated breast cancer detection systems.The upcoming artificial intelligence platforms,especially deep learning models,play an important role in image diagnosis and prediction.Initially,the histopathology biopsy images are taken from standard data sources.Further,the gathered images are given as input to the Multi-Scale Dilated Vision Transformer,where the essential features are acquired.Subsequently,the features are subjected to the Bidirectional Long Short-Term Memory(Bi-LSTM)for classifying the breast cancer disorder.The efficacy of the model is evaluated using divergent metrics.When compared with other methods,the proposed work reveals that it offers impressive results for detection.

Epidemiology and Histopathology of Cancers of the Upper Aerodigestive Tract in the ENT and Head and Neck Surgery Department of the Ignace Deen National Hospital

Introduction: Head and neck cancers represent a significant burden of cancer, collectively ranking fourth for cancer incidence and second for cancer mortality worldwide. Objective: To study the epidemiological and histopathological aspects of head and neck cancers in the ENT-CCF department of Ignace Deen National Hospital. Materials and Methods: This was a descriptive retrospective study covering a period of 5 years from September 1, 2016, to September 30, 2021. Results: We collected 43 cases of head and neck cancers, representing a hospital frequency of 1.85%. The mean age was 45.21 ± 13.23 years. Males predominated, accounting for 65.12%, compared to 34.88% for females, with a male-to-female ratio of 1.87. Housewives accounted for 27.90%, followed by farmers at 23.26% and traders/merchants at 18.60%, with 41.86% being uneducated. The main risk factors were tobacco (37.21%) and alcohol (34.88%). Pain (53.49%), dysphonia (51.16%), and dyspnea (39.53%) were the main presenting symptoms. Squamous cell carcinoma (74.42%) and large cell lymphoma (18.60%) were the most commonly cited histological types. Conclusion: Head and neck cancers remain relatively common in our country. Improving prognosis depends on early diagnosis of the condition, resuscitation resources, and prompt management.

Post-traumatic cauda equina nerve calcification:A case report

BACKGROUND Post-traumatic cauda equina nerve calcification is extremely rare in clinical practice,and its etiology,pathogenesis,treatment and prognosis are unclear.There are few studies and reports on Post-traumatic cauda equina nerve calci-fication,and this review reports a case of Post-traumatic cauda equina nerve calcification for reference.CASE SUMMARY A 52-year-old patient presented to our hospital with a history of lumbar spinal stenosis and a lumbar vertebral fracture caused by trauma.The patient's right lower limb had weakness in hip flexion,knee extension and plantarflexion with muscle strength grade 3,right ankle dorsiflexion and thumb dorsiflexion with muscle strength grade 0.The patient's skin sensation below the right knee plane disappeared.The patient's Computed tomography(CT)data showed signs of cauda equina nerve calcification and the terminal filaments in the plane of the third to fifth lumbar vertebrae.After treatment the patient's symptoms were slightly relieved.CONCLUSION We provide an extremely rare case of Post-traumatic cauda equina nerve calcification and offer a conservative treatment plan.However,the etiology,mechanism and treatment of Post-traumatic cauda equina nerve calcification are still unclear.This requires scholars to conduct more research and exploration in this area.

Renal calcification in children with renal tubular acidosis:What a paediatrician should know

Renal tubular acidosis(RTA)can lead to renal calcification in children,which can cause various complications and impair renal function.This review provides pediatricians with a comprehensive understanding of the relationship between RTA and renal calcification,highlighting essential aspects for clinical manage-ment.The article analyzed relevant studies to explore the prevalence,risk factors,underlying mechanisms,and clinical implications of renal calcification in children with RTA.Results show that distal RTA(type 1)is particularly associated with nephrocalcinosis,which presents a higher risk of renal calcification.However,there are limitations to the existing literature,including a small number of studies,heterogeneity in methodologies,and potential publication bias.Longitudinal data and control groups are also lacking,which limits our understanding of longterm outcomes and optimal management strategies for children with RTA and renal calcification.Pediatricians play a crucial role in the early diagnosis and management of RTA to mitigate the risk of renal calcification and associated complications.In addition,alkaline therapy remains a cornerstone in the treatment of RTA,aimed at correcting the acid-base imbalance and reducing the formation of kidney stones.Therefore,early diagnosis and appropriate therapeutic interventions are paramount in preventing and managing renal calcification to preserve renal function and improve long-term outcomes for affected children.Further research with larger sample sizes and rigorous methodologies is needed to optimize the clinical approach to renal calcification in the context of RTA in the pediatric population.

Nuclei Segmentation in Histopathology Images Using Structure-Preserving Color Normalization Based Ensemble Deep Learning Frameworks

This paper presents a novel computerized technique for the segmentation of nuclei in hematoxylin and eosin(H&E)stained histopathology images.The purpose of this study is to overcome the challenges faced in automated nuclei segmentation due to the diversity of nuclei structures that arise from differences in tissue types and staining protocols,as well as the segmentation of variable-sized and overlapping nuclei.To this extent,the approach proposed in this study uses an ensemble of the UNet architecture with various Convolutional Neural Networks(CNN)architectures as encoder backbones,along with stain normalization and test time augmentation,to improve segmentation accuracy.Additionally,this paper employs a Structure-Preserving Color Normalization(SPCN)technique as a preprocessing step for stain normalization.The proposed model was trained and tested on both single-organ and multi-organ datasets,yielding an F1 score of 84.11%,mean Intersection over Union(IoU)of 81.67%,dice score of 84.11%,accuracy of 92.58%and precision of 83.78%on the multi-organ dataset,and an F1 score of 87.04%,mean IoU of 86.66%,dice score of 87.04%,accuracy of 96.69%and precision of 87.57%on the single-organ dataset.These findings demonstrate that the proposed model ensemble coupled with the right pre-processing and post-processing techniques enhances nuclei segmentation capabilities.

Reaction mechanisms of low-grade molybdenum concentrate during calcification roasting process

The effects of Ca-based additives on roasting properties of low-grade molybdenum concentrate were studied. The resultsshow that calcium-based additives can react with molybdenum concentrate to form CaSO4 and CaMoO4. The initial oxidationtemperature of MoS2 is 450℃, while the formation of CaMoO4 and CaSO4 occurs above 500℃. The whole calcification reactionsare nearly completed between 600 and 650℃. However, raising the temperature further helps for the formation of CaMoO4 but isdisadvantageous to sulfur fixing rate and molybdenum retention rate. Calcification efficiency of Ca-based additives follows theorder： Ca（OH）2〉CaO〉CaCO3. With increasing the dosage of Ca（OH）2, the molybdenum retention rate and sulfur-fixing rate rise, butexcessive dosages would consume more acid during leaching process. The appropriate mass ratio of Ca（OH）2 to molybdenumconcentrate is 1：1. When roasted at 650 ℃ for 90 min, the molybdenum retention rate and the sulfur-fixing rate of low-grademolybdenum concentrate reach 100% and 92.92%, respectively, and the dissolution rate of molybdenum achieves 99.12% withcalcines being leached by sulphuric acid.

Role of different imaging modalities of vascular calcification in predicting outcomes in chronic kidney disease

Vascular calcification(VC) is common among patientswith chronic kidney disease(CKD).The severity of VC is associated with increased risk of cardiovascular events and mortality.Risk factors for VC include traditional cardiovascular risk factors as well as CKD-related risk factors such as increased calcium and phosphate load.VC is observed in arteries of all sizes from small arterioles to aorta,both in the intima and the media of arterial wall.Several imaging techniques have been utilized in the evaluation of the extent and the severity of VC.Plain radiographs are simple and readily available but with the limitation of decreased sensitivity and subjective and semi-quantitative quantification methods.Mammography,especially useful among women,offers a unique way to study breast arterial calcification,which is largely a medial-type calcification.Ultrasonography is suitable for calcification in superficial arteries.Analyses of wall thickness and lumen size are also possible.Computed tomography(CT) scan,the gold standard,is the most sensitive technique for evaluation of VC.CT scan of coronary artery calcification is not only useful for cardiovascular risk stratification but also offers an accurate and an objective analysis of the severity and progression.

Coronary artery calcification in chronic kidney disease:An update

Arterial calcification is a well-recognized complication of advanced atherosclerosis.Chronic kidney disease(CKD) is characterized by significantly more pronounced,dis-seminated and fast-progressing calcification of the vascular system,including the coronary arteries.New computed tomography-based imaging techniques al-low for the noninvasive assessment and monitoring of calcification in different vascular sites.Coronary artery calcification(CAC) develops early in the course of CKD and is tightly associated with mineral and bone disor-ders,which include but are not limited to secondary hyperparathyroidism.In this review,recent data on the pathogenesis of CAC development and progression are discussed,with a special emphasis on fibroblast growth factor 23 and its co-receptor,klotho.The prevalence,progression and prognostic significance of CAC are reviewed separately for patients with end-stage renal disease treated with dialysis,kidney transplant recipi-ents and patients with earlier stages of CKD.In the last section,therapeutic considerations are discussed,with special attention paid to the importance of treatment that addresses mineral and bone disorders of CKD.

Elevated IL-37 levels in the plasma of patients with severe coronary arterycalcification

Background Coronary artery calcification （CAC） is a predictor of cardiovascular events and plaque burden and is closely associatedwith chronic inflammation. Intedeukin （IL）-37 is a newly discovered member of the IL-1 family and is considered an anti-inflammatorycytokine. Our recent study on mice indicated that IL-37 could attenuate atherosclerosis and vascular calcification, which suggests that IL-37could be associated with the development of atherosclerosis and related diseases. The aim of this study was to investigate if IL-37 plays arole in the progression of CAC in patients. Methods Two hundred participants with suspected cardiovascular disease were recruited. Thelevels of plasma IL-37, osteoprotegerin （OPG）, hypersensitive C-reactive protein （hsCRP） together with other biochemical parameters weremeasured, and a coronary calcium assessment was carried out by multi-detector row CT. A score of 〈 10 AU （Agatston units） denotes anabsence of CAC, a score of 11-100 AU denotes mild CAC, 101-400 denotes moderate CAC, and 〉 400 AU denotes severe CAC. ResultsOur initial data showed that there were no apparent differences in plasma IL-37 levels among patients with or without mild or moderate CAC.However, IL-37 levels were significantly increased in patients with severe CAC （P 〈 0.001）. Similar results were observed for plasma OPGand hsCRP levels. When IL-37 levels in patients with severe calcification were compared with that in all of the other non-severe CAC groups,it became apparent that there was a significant positive correlation between IL-37 level and severe CAC （r = 0.360, P 〈 0.001; OR = 1.033）using Spearrnan＇s correlation and binary logistic regression analysis. Conclusions This study demonstrates that the anti-inflammatory cy-tokine IL-37 is associated with high coronary calcium levels, suggesting that IL-37 expression may be caused by the activation ofinf/amma-tion and that IL-37 might become a predictor of severe CAC in the future, which requires further investigation.

Recovery of alkali and alumina from Bayer red mud by the calcification–carbonation method

Red mud produced in the Bayer process is a hazardous solid waste because of its high alkalinity; however, it is rich in valuable components such as titanium, iron, and aluminum. In this study, a novel calcification-carbonation method was developed to recover alkali and alumina from Bayer red mud under mild reaction conditions. Batch experiments were performed to evaluate the potential effects of im- portant parameters such as temperature, amount of CaO added, and CO2 partial pressure on the recovery of alkali and alumina. The results showed that 95.2% alkali and 75.0% alumina were recovered from red mud with decreases in the mass ratios of Na2O to Fe2O3 and of Al2O3 to Fe2O3 from 0.42 and 0.89 to 0.02 and 0.22, respectively. The processed red mud with less than 0.5wt% Na2O can potentially be used as a construction material.

Roasting and leaching behaviors of vanadium and chromium in calcification roasting–acid leaching of high-chromium vanadium slag

Calcification roasting–acid leaching of high-chromium vanadium slag(HCVS)was conducted to elucidate the roasting and leaching behaviors of vanadium and chromium.The effects of the purity of Ca O,molar ratio between Ca O and V_2O_5(n(Ca O)/n(V_2O_5)),roasting temperature,holding time,and the heating rate used in the oxidation–calcification processes were investigated.The roasting process and mechanism were analyzed by X-ray diffraction(XRD),scanning electron microscopy(SEM),and thermogravimetry–differential scanning calorimetry(TG–DSC).The results show that most of vanadium reacted with Ca O to generate calcium vanadates and transferred into the leaching liquid,whereas almost all of the chromium remained in the leaching residue in the form of(Fe_(0.6)Cr_(0.4))_2O_3.Variation trends of the vanadium and chromium leaching ratios were always opposite because of the competitive reactions of oxidation and calcification between vanadium and chromium with Ca O.Moreover,Ca O was more likely to combine with vanadium,as further confirmed by thermodynamic analysis.When the HCVS with Ca O added in an n(Ca O)/n(V_2O_5)ratio of 0.5 was roasted in an air atmosphere at a heating rate of 10°C/min from room temperature to 950°C and maintained at this temperature for 60 min,the leaching ratios of vanadium and chromium reached91.14%and 0.49%,respectively;thus,efficient extraction of vanadium from HCVS was achieved and the leaching residue could be used as a new raw material for the extraction of chromium.Furthermore,the oxidation and calcification reactions of the spinel phases occurred at 592and 630°C for n(Ca O)/n(V_2O_5)ratios of 0.5 and 5,respectively.