Cooperative effect of sodium lauryl sulfate collector and sodium pyrophosphate depressant on the flotation separation of lead oxide minerals from hematite

As a cornerstone of the national economy,the iron and steel industry generates a significant amount of sintering dust containing both valuable lead resources and deleterious elements.Flotation is a promising technique for lead recovery from sintering dust,but efficient separation from Fe_(2)O_(3) is still challenging.This study investigated the cooperative effect of sodium lauryl sulfate(SLS,C_(12)H_(25)SO_(4)Na)and sodium pyrophosphate(SPP,Na_(4)P_(2)O_(7))on the selective flotation of lead oxide minerals(PbOHCl and PbSO_(4))from hematite(Fe_(2)O_(3)).Optimal flotation conditions were first identified,resulting in high recovery of lead oxide minerals while inhibiting Fe_(2)O_(3) flotation.Zeta potential measurements,Fourier transform infrared spectroscopy(FT-IR)analysis,adsorption capacity analysis,and X-ray photoelectron spectroscopy(XPS)studies offer insights into the adsorption behaviors of the reagents on mineral surfaces,revealing strong adsorption of SLS on PbOHCl and PbSO_(4) surfaces and remarkable adsorption of SPP on Fe_(2)O_(3).The proposed model of reagent adsorption on mineral surfaces illustrates the selective adsorption behavior,highlighting the pivotal role of reagent adsorption in the separation process.These findings contribute to the efficient and environmentally friendly utilization of iron ore sintering dust for lead recovery,paving the way for sustainable resource management in the iron and steel industry.

Lacidipine,thiamine pyrophosphate and their combination on the ocular ischemic syndrome induced by bilateral common carotid artery ligation

AIM:To investigate the effect of lacidipine,thiamine pyrophosphate(TPP)and the combination of lacidipine and TPP against oxidative and inflammatory eye damage induced by bilateral common carotid artery ligation in rats.METHODS:Male albino Wistar rats were categorized as those who underwent sham surgery(SG),right and left common carotid cross-clamping and unclamping procedure(CCU),lacidipine+CCU(LCCU),TPP+CCU(TCCU),and combination of lacidipine and TPP(LTC)+CCU(LTCCU).One hour before anesthesia,the LCCU(n=6)received lacidipine(4 mg/kg,orally)and the TCCU(n=6)received TPP(20 mg/kg,intraperitoneally).The SG(n=6)and CCU(n=6)received the same volume of distilled water from the same route.After anesthesia(60 mg/kg ketamine,intraperitoneally),the necks of the rats were opened in the midline.Ischemia was created for 10min by placing clips on the right and left common carotid arteries.Rats in the SG only underwent subcutaneous incision.After 10min,the clips were removed and reperfusion was achieved for six days.Then,the animals were euthanized(120 mg/kg ketamine,intraperitoneally)and the levels of oxidant,antioxidant and proinflammatory cytokines in the eye tissues were determined.The retinal tissue of the eye was also examined histopathologically.RESULTS:Lacidipine,TPP,and LTC significantly prevent the increase in malondialdehyde,tumor necrosis factoralpha,interleukin-1β(IL-1β),and IL-6 levels,decrease in total glutathione levels,superoxide dismutase and catalase activities and histopathological retinal damage in eye tissue induced by bilateral common carotid artery ligation in rats.The impact of these drugs on protection is determined to be LTC>lacidipine>TPP.CONCLUSION:As a result of the study,it is concluded that LTC may be more effective than lacidipine and TPP alone in treating ocular ischemic syndrome.

Artificial intelligence-assisted colorimetry for urine glucose detection towards enhanced sensitivity,accuracy,resolution,and anti-illuminating capability

Colorimetry often suffers from deficiency in quantitative determination,susceptibility to ambient illuminance,and low sensitivity and visual resolution to tiny color changes.To offset these deficiencies,we incorporate deep machine learning into colorimetry by introducing a convolutional neural network(CNN)with powerful parallel processing,self-organization,and self-learning capabilities.As a proof of concept,a plasmonic nanosensor is proposed for the colorimetric detection of glucose by coupling Benedict’s reagent with gold nanoparticles(AuNPs),which relies on the assemble of AuNPs into dendritic nanochains by Cu2O.The distinct difference of refractive index between Cu2O and Au and the localized surface plasmon resonance coupling effect among AuNPs leads to a broad spectral shift as well as abundant color changes,thereby providing sufficient data for selflearning enabled by machine learning.The CNN is then used to fully diversify the learning and training of the images from standard samples under different ambient conditions and to obtain a classifier that can not only recognize tiny color changes that are imperceptible to human eyes,but also exhibit high accuracy and excellent anti-environmental interference capability.This classifier is then compiled as an application(APP)and implanted into a smartphone with Android environment.306 clinical urine samples were detected using the proposed method and the results showed a satisfactory correlation(87.6%)with that of a standard blood glucose test method.More importantly,this method can be generalized to other applications in colorimetry,and more broadly,in other scientific domains that involve image analysis and quantification.

Quantifying Hypochlorous Acid Concentration in Environmental Water Using Smartphone Colorimetry

In this study,we developed an eff ective method to detect hypochlorite acid(HClO)by using methylene blue(MB)derivative(BPY1).BPY1 was selectively oxidized through HClO,and the solution color changed from colorless to blue.In the presence of HClO,the ultraviolet–visible(UV–vis)spectra and concentration of HClO had a linear relationship with a detection limit of 0.5μM.Furthermore,a test paper for HClO monitoring was successfully prepared using the BPY1 probe,and the observed detection limit by the naked eye was estimated at 5μM.Additionally,using the BPY1 probe,HClO could also be detected through smartphone colorimetry,and the method showed a good recovery ranging from 98.7 to 104.0%for HClO detection in an actual water sample.Especially for developing countries,such a low-cost and highly sensitive detection method provides a simple and practical method for monitoring HClO in water.

Preparation of nano-sized cerium and titanium pyrophosphates via solid-state reaction at room temperature

Nano-sized cerium-titanium pyrophosphates Ce1-xTixP2O7 （with x = 0, 0.2, 0.5, 0.7, 0.9, and 1.0） were obtained by grinding a mixture of Ce（SO4）2·4H2O, Ti（SO4）2, and Na4P2O7·10H2O in the presence of surfactant PEG-400 at room temperature, washing the mixture with water to remove soluble inorganic salts, and drying at 100℃. The products and their calcined samples were characterized using ultraviolet-visible spectroscopy （UV-vis）, thermogravimetry and differential thermal analyses （TG/DTA）, X-ray powder diffraction （XRD）, and transmission electron microscopy （TEM）. The results show that nano-sized Ce1-xTixP2O7 behave as an excellent UV-shielding material. Thereinto, the CeP2O7 has the most excellent UV-shielding effect, and the amorphous state of Ce0.8Ti0.2P2O7 can keep at a higher temperature than CeP2O7. Therefore, the stabilization of the amorphous state of the cerium pyrophosphates was carded out by doping titanium. This stabilization is a significant improvement, which enables to apply these amorphous pyrophosphates not only to cosmetics and paints, but also plastics and films.

Promotional Effect of Bismuth as Dopant in Bi-Doped Vanadyl Pyrophosphate Catalysts for Selective Oxidation of n-Butane to Maleic Anhydride

Bismuth-promoted （1% and 3%） vanadyl pyrophosphate catalysts were prepared by refluxing Bi（NO3）4.5H2O and VOPO4.2H2O in isobutanol. The incorporation of Bi into the catalysts lattice increased the surface area and lowered the overall V oxidation state. Profiles of temperature programmed reduction （TPR） in H2 show a significant shift of the maxima of major reduction peaks to lower temperatures for the Bi-promoted catalysts. A new peak was also observed at the low temperature region for the catalyst with 3% of Bi dopant. The addition of Bi also increased the total amount of oxygen removed from the catalysts. The reduction pattern and reactivity information provide fundamental insight into the catalytic properties of the catalysts. Bi-promoted catalysts were found to be highly active （71% and 81% conversion for 1% and 3% Bi promoted catalysts, respectively, at 703 K）, as compared to the unpromoted material （47% conversion）. The higher activity of the Bi-promoted catalysts is due to that these catalysts possess highly active and labile lattice oxygen. The better catalytic performance can also be attributed to the larger surface area.

Synthesis and Biodegradation of St-g-poly(MMA-co-VAc) Initiated by Manganic Pyrophosphate

Methyl methacrylate(MMA) and vinyl acetate(VAc) were grafted onto corn starch with manganic pyrophosphate{[Mn(H 2P 2O 7) 3] 3-} as the initiator and water as the reaction medium. The influences of reaction conditions, including pH value, initiator concentration, monomer concentration and its composition, on percent grafting and grafting efficiency were investigated. The graft copolymer was characterized by means of IR spectroscopy, scanning electron micrograph(SEM) and 1H NMR spectroscopy. The biodegradation experiment showed that the degradation of corn starch-g-poly(MMA-co-VAc) was mainly from starch. However, after poly VAc in the side chain was transformed into poly vinyl alcohol(PVA), both starch and the grafted side chain could be degraded completely.

A biomimetic antitumor nanovaccine based on biocompatible calcium pyrophosphate and tumor cell membrane antigens

Currently,the cancer immunotherapy has made great progress while antitumor vaccine attracts substantial attention.Still,the selection of adjuvants as well as antigens are always the most crucial issues for better vaccination.In this study,we proposed a biomimetic antitumor nanovaccine based on biocompatible nanocarriers and tumor cell membrane antigens.Briefly,endogenous calcium pyrophosphate nanogranules with possible immune potentiating effect are designed and engineered,both as delivery vehicles and adjuvants.Then,these nanocarriers are coated with lipids and B16-OVA tumor cell membranes,so the biomembrane proteins can serve as tumor-specific antigens.It was found that calcium pyrophosphate nanogranules themselves were compatible and possessed adjuvant effect,while membrane proteins including tumor associated antigen were transferred onto the nanocarriers.It was demonstrated that such a biomimetic nanovaccine could be well endocytosed by dendritic cells,promote their maturation and antigen-presentation,facilitate lymph retention,and trigger obvious immune response.It was confirmed that the biomimetic vaccine could induce strong T-cell response,exhibit excellent tumor therapy and prophylactic effects,and simultaneously possess nice biocompatibility.In general,the present investigation might provide insights for the further design and application of antitumor vaccines.

Phylogenetic analysis of aerobic anoxygenic phototrophic bacteria and their relatives based on farnesyl pyrophosphate synthase gene

The study aims to reveal phylogenetic and evolutionary relationship between aerobic anoxygenic phototrophic bacteria（AAnPB） and their relatives,anaerobic anoxygenic phototrophic bacteria（AnAnPB） and nonphototrophic bacteria（NPB,which had high homology of 16S rDNA gene with AAnPB and fell into the same genus）,and validate reliability and usefulness of farnesyl pyrophosphate synthase（FPPS） gene for the phylogenetic determination.FPPS genes with our modified primers and 16S rDNA genes with general primers,were amplified and sequenced or retrieved from GenBank database.In contrast to 16S rDNA gene phylogenetic tree,AAnPB were grouped into two clusters and one branch alone with no intermingling with NPB and AnAnPB in the tree constructed on FPPS.One branch of AAnPB,in both trees,was located closer to outgroup species than AnAnPB,which implicated that some AAnPB would be diverged earlier in FPPS evolutionary history than AnAnPB and NPB.Some AAnPB and NPB were closer located in both trees and this suggested that they were the closer relatives than AnAnPB.Combination codon usage in FPPS with phylogenetic analysis,the results indicates that FPPS gene and 16S rRNA gene have similar evolutionary pattern but the former seems to be more reliable and useful in determining the phylogenic and evolutionary relationship between AAnPB and their relatives.This is the first attempt to use a molecular marker beside 16S rRNA gene for studying the phylogeny of AAnPB,and the study may also be helpful in understanding the evolutionary relationship among phototrophic microbes and the trends of photosynthetic genes transfer.

Nanocrystalline Iron Pyrophosphate-Regulated Amorphous Phosphate Overlayer for Enhancing Solar Water Oxidation

A rational regulation of the solar water splitting reaction pathway by adjusting the surface composition and phase structure of catalysts is a substantial approach to ameliorate the sluggish reaction kinetics and improve the energy conversion efficiency.In this study,we demonstrate a nanocrystalline iron pyrophosphate(Fe_(4)(P_(2)O_(7))_(3),FePy)-regulated hybrid overlayer with amorphous iron phosphate(FePO_(4),FePi)on the surface of metal oxide nanostructure with boosted photoelectrochemical(PEC)water oxidation.By manipulating the facile electrochemical surface treatment followed by the phosphating process,nanocrystalline FePy is localized in the FePi amorphous overlayer to form a heterogeneous hybrid structure.The FePy-regulated hybrid overlayer(FePy@FePi)results in significantly enhanced PEC performance with long-term durability.Compared with the homogeneous FePi amorphous overlayer,FePy@FePi can improve the charge transfer efficiency more significantly,from 60% of FePi to 79%of FePy@FePi.Our density-functional theory calculations reveal that the coexistence of FePi and FePy phases on the surface of metal oxide results in much better oxygen evolution reaction kinetics,where the FePi was found to have a typical down-hill reaction for the conversion from OH*to O_(2),while FePy has a low free energy for the formation of OH*.

Remodeling Isoprene Pyrophosphate Metabolism for Promoting Terpenoids Bioproduction

Terpenoids are the largest family of natural products.They are made from the building block isoprene pyrophosphate(IPP),and their bioproduction using engineered cell factories has received a great deal of attention.To date,the insufficient metabolic supply of IPP remains a great challenge for the efficient synthesis of terpenoids.In this work,we discover that the imbalanced metabolic flux distribution between the central metabolism and the IPP supply hinders IPP accumulation in Bacillus subtilis(B.subtilis).Therefore,we remodel the IPP metabolism using a series of genetically encoded two-input-multioutput(TIMO)circuits that are responsive to pyruvate or/and malonyl-CoA,resulting in an IPP pool that is significantly increased by up to four-fold.As a proof-of-concept validation,we design an IPP metabolism remodeling strategy to improve the production of three valuable terpenoids,including menaquinone-7(MK-7,4.1-fold),lycopene(9-fold),andβ-carotene(0.9-fold).In particular,the titer of MK-7 in a 50-L bioreactor reached 1549.6 mg·L^(-1),representing the highest titer reported so far.Thus,we propose a TIMO genetic circuits-assisted IPP metabolism remodeling framework that can be generally used for the synergistic fine-tuning of complicated metabolic modules to achieve the efficient bioproduction of terpenoids.

Mo/Fe bimetallic pyrophosphates derived from Prussian blue analogues for rapid electrocatalytic oxygen evolution

Efficient and stable oxygen evolution electrocatalysts are indispensable for industrial applications of water splitting and hydrogen production.Herein,a simple and practical method was applied to fabricate(Mo,Fe)P2O7@NF electrocatalyst by directly growing Mo/Fe bimetallic pyrophosphate derived from Prussian blue analogues on three-dimensional porous current collector.In alkaline media,the developed material possesses good hydrophilic features and exhibits best-in-class oxygen evolution reaction(OER)performances.Surprisingly,the(Mo,Fe)P_(2)O_(7)@NF only requires overpotentials of 250 and 290 mV to deliver 100 and 600 mA cm^(-2)in 1 mol L^(-1)KOH,respectively.Furthermore,the(Mo,Fe)P_(2)O_(7)@NF shows outstanding performances in alkaline salty water and 1 mol L^(-1)high purity KOH.A worthwhile pathway is provided to combine bimetallic pyrophosphate with commercial Ni foam to form robust electrocatalysts for stable electrocatalytic OER,which has a positive impact on both hydrogen energy application and environmental restoration.

Calcium pyrophosphate dihydrate crystals in a 9-year-old with osteomyelitis of the knee:A case report

BACKGROUND Calcium pyrophosphate dihydrate deposition disease(CPPD),or pseudogout,is an inflammatory arthritis common among elderly patients,but rarely seen in patients under the age of 40.In the rare cases presented of young patients with CPPD,genetic predisposition or related metabolic conditions were almost always identified.CASE SUMMARY The authors report the case of a 9-year-old boy with no past medical history who presented with acute knee pain and swelling after a cat scratch injury 5 d prior.Synovial fluid analysis identified calcium pyrophosphate dihydrate crystals.Further MRI analysis identified osteomyelitis and a small soft tissue abscess.CONCLUSION This case presents the extremely rare diagnostic finding of calcium pyrophosphate dihydrate crystals in a previously healthy pediatric patient.The presence of osteomyelitis presents a unique insight into the pathogenesis of these crystals in pediatric patients.More research needs to be done on the role of CPPD in pediatric arthritis and joint infection.

The behavior of cesium adsorption on zirconyl pyrophosphate

Zirconyl pyrophosphate(ZrP_2O_7) was prepared and Cs adsorption behavior was studied.Results show that the distribution coefficient of Cs adsorption on ZrP_2O_7 was about 2800 mL/g.Ion exchange capacity of ZrP_2O_7 was0.35 mmol/g.In dynamic tests,Cs can be separated from other fission products very well by ZrP_2O_7.The ZrP_2O_7was stable both at high temperatures and in high concentration of nitric acid.The Cs adsorption by ZrP_2O_7 is a monolayer and chemical adsorption.

Two farnesyl pyrophosphate synthases,GhFPS1–2,in Gossypium hirsutum are involved in the biosynthesis of farnesol to attract parasitoid wasps

Sesquiterpenoids play an import role in the direct or indirect defense of plants.Farnesyl pyrophosphate synthases(FPSs)catalyze the biosynthesis of farnesyl pyrophosphate,which is a key precursor of farnesol and(E)-β-farnesene.In the current study,two FPS genes in Gossypium hirsutum,GhFPS1 and GhFPS2,were heterologously cloned and functionally characterized in a greenhouse setting.The open reading frames for full-length GhFPS1 and GhFPS2 were each 1029 nucleotides,and encoded two proteins of 342 amino acids with molecular weights of 39.4 kDa.The deduced amino acid sequences of GhFPS1–2 showed high identity to FPSs of other plants.Quantitative real-time PCR analysis revealed that GhFPS1 and GhFPS2 were highly expressed in G.hirsutum leaves,and were upregulated in methyl jasmonate(MeJA)-,methyl salicylate(MeSA)-and aphid infestation-treated cotton plants.The recombinant proteins of either GhFPS1 or GhFPS2 plus calf intestinal alkaline phosphatase could convert geranyl diphosphate(GPP)or isopentenyl diphosphate(IPP)to one major product,farnesol.Moreover,in electrophysiological response and Y-tube olfactometer assays,farnesol showed obvious attractiveness to female Aphidius gifuensis,which is an important parasitic wasp of aphids.Our findings suggest that two GhFPSs are involved in farnesol biosynthesis and they play a crucial role in indirect defense of cotton against aphid infestation.

Gene expression and histopathological evaluation of thiamine pyrophosphate on optic neuropathy induced with ethambutol in rats

AIM： To compare the effects of thiamine pyrophosphate（TPP） and thiamine（TM） in oxidative optic neuropathy in rats induced by ethambutol.METHODS： The animals were divided into four groups：a control group（CG）,an ethambutol control（ETC） group,TM plus ethambutol group（TMG）,and TPP plus ethambutol group（TPPG）.One hour after intraperitoneal administration of TM 20 mg/kg to the TMG group and TPP 20 mg/kg to TPPG group,30 mg/kg ethambutol was given via gavage to all the groups but the CG.This procedure was repeated once daily for 90 d.After that period,all rats were exposed to high levels of anaesthesia in order to investigate the gene expression of malondialdehyde and glutathione in removed optic nerve tissue and histopathologically to examine these tissues. RESULTS： Malondialdehyde gene expression significantly increased,whereas glutathione gene expression significantly decreased in the ETC group compared to the CG.TM could not prevent the increase of malondialdehyde gene expression and the decrease of glutathione,while TPP significantly could suppress.Histopathologically,significant vacuolization in the opticnerve,single-cell necrosis in the glial cells,and a decrease in oligodendrocytes were observed in the ETC group.Vacuolization in the optic nerve,a decrease in oligodendrocytes and single-cell necrosis were found in the TMG group,while no pathological finding was observed in the TPPG group except for mild vacuolization.CONCLUSION： TPP protects the optic nerve against the ethambutol-induced toxicity but TM does not.TPP can be beneficial in prophilaxis of optic neuropathy in ethambutol therapy.

Distinguishing erosive osteoarthritis and calcium pyrophosphate deposition disease

Erosive osteoarthritis is a term utilized to describe a specific inflammatory condition of the interphalangeal and first carpal metacarpal joints of the hands. The term has become a part of medical philosophical semantics and paradigms, but the issue is actually more complicated. Even the term osteoarthritis(nonerosive) has been controversial, with some suggesting osteoarthrosis to be more appropriate in view of the perspective that it is a non-inflammatory process undeserving of the "itis" suffix. The term "erosion" has also been a source of confusion in osteoarthritis, as it has been used to describe cartilage, not bone lesions. Inflammation in individuals with osteoarthritis actually appears to be related to complicating phenomena, such as calcium pyrophosphate and hydroxyapatite crystal deposition producing arthritis. Erosive osteoarthritis is the contentious term. It is used to describe a specific form of joint damage to specific joints. The damage has been termed erosions and the distribution of the damage is to the interphalangeal joints of the hand and first carpal metacarpal joint. Inflammation is recognized by joint redness and warmth, while X-rays reveal alteration of the articular surfaces, producing a smudged appearance. This ill-defined, joint damage has a crumbling appearance and is quite distinct from the sharply defined erosions of rheumatoid arthritis and spondyloarthropathy. The appearance is identical to those found with calcium pyrophosphate deposition disease, both in character and their unique responsiveness to hydroxychloroquine treatment. Low doses of the latter often resolve symptoms within weeks, in contrast to higher doses and the months required for response in other forms of inflammatory arthritis. Reconsidering erosive osteoarthritis as a form of calcium pyrophosphate deposition disease guides physicians to more effective therapeutic intervention.

I₂/Nanostructured Pyrophosphate : A Mild and Efficient Catalyst for the Selective Protection of Carbonyl Compounds

A new solvent free method for protection of carbonyl compounds as their thioacetals has been accomplished through the use of iodine supported on nanostructured pyrophosphate. Advantages of the methodology include very short reaction time, the requirement for minimum amounts of catalyst, the remarkably simple experimental procedure, and no necessity for solvents or inert atmospheres, excellent yields and recyclability of the catalyst used. An efficient method for the chemoselective thioacetalization of ketones in the presence of aldehydes using I2/nanostructured pyrophosphate is also reported in this article. The nanostructured pyrophosphate was characterized by scanning electron microscopy, X-ray diffraction, infrared spectroscopy, Transmission electron microscopy and thermal gravimetric analysis, respectively.

Single-cell analysis identifies phospholysine phosphohistidine inorganic pyrophosphate phosphatase as a target in ulcerative colitis

BACKGROUND Ulcerative colitis(UC)is a chronic gastrointestinal disorder characterized by inflammation and ulceration,representing a significant predisposition to colorectal cancer.Recent advances in single-cell RNA sequencing(scRNA-seq)technology offer a promising avenue for dissecting the complex cellular interactions and molecular signatures driving UC pathology.AIM To utilize scRNA-seq technology to dissect the complex cellular interactions and molecular signatures that underlie UC pathology.METHODS In this research,we integrated and analyzed the scRNA-seq data from UC patients.Moreover,we conducted mRNA and protein level assays as well as pathology-related staining tests on clinical patient samples.RESULTS In this study,we identified the sustained upregulation of inflammatory response pathways during UC progression,characterized the features of damaged endothelial cells in colitis.Furthermore,we uncovered the downregulation of phospholysine phosphohistidine inorganic pyrophosphate phosphatase(LHPP)has a negative correlation with signal transducer and activator of transcription 3.Significant downregulation of LHPP in UC patient tissues and plasma suggests that LHPP may serve as a potential therapeutic target for UC.This paper highlights the importance of LHPP as a potential key target in UC and unveils its potential role in inflammation regulation.CONCLUSION The findings suggest that LHPP may serve as a potential therapeutic target for UC,emphasizing its importance as a potential key target in UC and unveiling its role in inflammation regulation.

Calcium pyrophosphate deposition disease of the temporomandibular joint invading the middle cranial fossa:Two case reports

BACKGROUND Pseudogout is a benign joint lesion caused by the deposition of calcium pyrophosphate dihydrate crystals,but it is invasive.Pseudogout of the temporomandibular joint(TMJ)is uncommon,and it rarely invades the skull base or penetrates into the middle cranial fossa.The disease has no characteristic clinical manifestations and is easily misdiagnosed.CASE SUMMARY We present two cases of tophaceous pseudogout of the TMJ invading the middle cranial fossa.A 46-year-old woman with a history of diabetes for more than 10 years was admitted to the hospital due to swelling and pain in the right temporal region.Another patient,a 52-year-old man with a mass in the left TMJ for 6 years,was admitted to the hospital.Maxillofacial imaging showed a calcified mass and severe bone destruction of the skull base in the TMJ area.Both patients underwent excision of the lesion.The lesion was pathologically diagnosed as tophaceous pseudogout.The symptoms in these patients were relieved after surgery.CONCLUSION Tophaceous pseudogout should be considered when there is a calcified mass in the TMJ with or without bone destruction.A pathological examination is the gold standard for diagnosing this disease.Surgical treatment is currently the recommended treatment,and the prognosis is good after surgery.