Acid Crystals Research Articles

The Therapeutic Effect of Phosphopeptide P140 Attenuates Inflammation Induced by Uric Acid Crystals in Gout Arthritis Mouse Model

Gout is a painful form of inflammatory arthritis characterized by the deposition of monosodium urate (MSU) crystals in the joints. The aim of this study was to investigate the effect of peptide P140 on the inflammatory responses in crystal-induced mouse models of gout and cell models including MSU-treated human cells. Injection of MSU crystals into the knee joint of mice induced neutrophil influx and inflammatory hypernociception. Injection of MSU crystals subcutaneously into the hind paw induced edema and increased pro-inflammatory cytokines levels. Treatment with P140 effectively reduced hypernociception, the neutrophil influx, and pro-inflammatory cytokine levels in these experimental models. Furthermore, P140 modulated neutrophils chemotaxis in vitro and increased apoptosis pathways through augmented caspase 3 activity and reduced NFκB phosphorylation. Moreover, P140 increased the production of the pro-resolving mediator annexin A1 and decreased the expression of the autophagy-related ATG5-ATG12 complex and HSPA8 chaperone protein. Overall, these findings suggest that P140 exerts a significant beneficial effect in a neutrophilic inflammation observed in the model of gout that can be of special interest in the design of new therapeutic strategies.

Literatur Review: Peran konseling gizi dan senam ergonomik dalam menurunkan kadar asam urat pada penderita gout

Gout is a disorder caused by inflammation of the joints due to the deposition of uric acid crystals stored in the joints. The causative factors are age, excessive purine intake, obesity, alcoholic beverages, and lack of physical activity. Various efforts can be made to overcome this, including nutritional counseling and physical activity, such as gymnastics. The study aims to provide descriptive information regarding the effect of nutritional counseling on a low-purine diet and ergonomic gymnastics in reducing uric acid levels in patients with gout. Literature review research was conducted using the keywords "Counseling, Ergonomic Exercise, Uric acid, and Gout" on the Google Scholar search engine and other electronic databases, namely Proquest, BMC, and Cochrane review. Scientific articles are published in national and international journals that can be accessed openly, published between 2010-2020. From these results, 13 articles were selected for review. The literature review was conducted in an unsystematic narrative review. The results of the study state that providing counseling using various media can be one solution to help reduce pain and reduce one's uric acid levels, namely through counseling or nutrition counseling and ergonomic exercises. Counseling can provide insight or knowledge related to a low-purine diet, while ergonomic exercises provide the impact of physical fitness on the patient's health. The combination of providing nutritional counseling and ergonomic exercises can reduce uric acid levels in patients with gout.

Identification of Uric Acid Crystals Accumulation in Human and Animal Tissues Using Combined Morphological and Raman Spectroscopy Analysis.

Gout is a metabolic condition, common to animals and humans, issuing from the excessive accumulation of end products of proteins degradation. In this study, histopathological and cytological examinations, combined with Raman spectroscopy, have been performed to investigate tissue samples from reptiles, chickens, and humans, presenting lesions produced by uric acid accumulation. As a result of classic processing and staining techniques commonly used in the anatomopathological diagnosis, uric acid crystals lose their structural characteristics, thus making difficult a precise diagnostic. Therefore, complementary diagnostic methods, such as Raman spectroscopy, are needed. This study compares from several perspectives the above mentioned diagnostic methods, concluding that Raman spectroscopy provides highlights in the diagnosis of gout in humans and animals, also adding useful information to differential diagnosis of lesions.

Cluster-in-Molecule Method Combined with the Domain-Based Local Pair Natural Orbital Approach for Electron Correlation Calculations of Periodic Systems.

The cluster-in-molecule (CIM) method was extended to systems with periodic boundary conditions (PBCs) in a previous work (PBC-CIM) [J. Chem. Theory Comput.2019, 15, 2933], which is able to compute the electronic structures of periodic systems at second-order Møller-Plesset perturbation theory (MP2) and coupled cluster singles and doubles (CCSD) levels. However, the high computational costs of CCSD with respect to the size of clusters limit the usage of PBC-CIM to crystals with small or medium unit cells. In this work, we further develop the PBC-CIM method by employing the domain-based local pair natural orbital (DLPNO) methods for the electron correlation calculations of clusters to reduce the computational costs. The combined approach allows CCSD with perturbative triples, denoted as CCSD(T), to be computationally available for accurate descriptions of periodic systems. The distant-pair correction is also implemented to improve the accuracy of PBC-CIM. As in the molecular cases, the distant pair correction significantly improves the accuracy of various PBC-CIM methods with few additional costs. The PBC-CIM-DLPNO-CCSD(T) approach has been applied to investigate the optimized lattice parameter of the cubic LiCl crystal and two adsorption problems (CO on the NaCl(100) surface and H2O on the h-BN surface). The results show that the CIM-DLPNO-CCSD(T) method offers accurate and efficient descriptions for the studied systems. Another application to the cohesive energy of the acetic acid crystal reveals that large basis sets are necessary for reliable calculations on the cohesive energies of molecular crystals.

Color-tunable and high-quantum-yield afterglow of carbon dots by covalent fixation

Because of the difficulties in populating and stabilizing the high energy triplet excited states, achieving violet organic afterglow at ambient conditions is still a formidable challenge. In this work, we propose an efficient strategy to activate violet and deep-blue afterglow of high energy triplet excited state by in situ embedding of carbon dots (CDs) into cyanuric acid crystals (CA) (named CDs@CA). The formation of covalent bonds in CDs@CA were found crucial in activating the afterglow with lifetime and phosphorescence quantum yields up to 1.80 s and 39%, respectively. Furthermore, the relationship between luminescence and copolymerization (covalent bonding) of CDs@CA were explored, which provides evidence for the regularity of multiple luminescent centers. A light-stimulated response of CDs@CA was found useful for applications in advanced anti-counterfeiting. These results provide a foundation for designing highly efficient violet and deep-blue organic afterglow materials with potential applications in the fields of bioimaging, anticounterfeiting, and optoelectronic devices.

Perfil cristalúrico em ovinos suplementados com cloreto de amônio

ABSTRACT Although urinary crystals are habitual components, urolithiasis formation is always preceded by these concretions. We aimed to identify the change in the crystalline profile in sheep supplemented with ammonium chloride. Twenty-five male sheep aged three months, feedlot and randomly distributed into three groups were used: Control Group (CG) n = 5 did not receive Ammonium Chloride; G200 Group (n=10) (200mg/kg) of Ammonium Chloride for 56 consecutive days; G500 Group (n=10) (500mg/kg) of Ammonium Chloride for 56 consecutive days, administered daily orally. Sampling times and clinical evaluation were performed at seven days, with M0 (immediately before Ammonium Chloride), M1 (seven days after) until M8, totaling 70 days of feedlot. Urine samples were performed to identify the presence, type, and quantity of crystals. There was an increase in crystalluria in all groups in relation to time due to dietary influence, mainly in the CG, which presented more crystals of amorphous calcium phosphate and calcium oxalate. In addition, the G500 Group presented a higher presence of urate/uric acid crystals after urinary acidification, which are closely related to urinary pH.

Gout in the course of systemic lupus erythematosus: Literature review and case study report

Gout is one of the relatively common inflammatory diseases of the joints. It is caused by the deposition of uric acid crystals in the tissues, which induces an acute or chronic inflammatory process. Elevated serum uric acid levels are usually found long before symptoms appear, and it is worth emphasizing that not every hyperuricemic patient will ever develop gout symptoms. The onset of gout is characterized by periodic joint inflammation, which may be triggered by various stress factors (trauma, infection), certain medications, dietary mistakes, and excessive exercise. Over time, repeated joint inflammation causes permanent joint damage. Most often, deposits of urate crystals are located in places with poorer blood supply and exposed to increased pressure, such as joints and soft tissues (e.g., auricles). The coexistence of gout and autoimmune diseases is relatively rare. While for many years it was believed that gout was not associated with other systemic connective tissue diseases, gout has been described in the course of systemic lupus erythematosus, systemic sclerosis, mixed connective tissue disease, psoriatic arthritis, ankylosing spondylitis, and rheumatoid arthritis. The presented systematic review also describes a case of a patient with longlasting systemic lupus erythematosus who was diagnosed with gout.

Sodium glucose co-transport 2 inhibitors for gout treatment.

Hyperuricemia remains the most prevalent cause of gout. Gout patients present with joint inflammation and uric acid crystals deposition manifesting as tophi. The association of gout with increased risk of insulin resistance, diabetes, metabolic disorders, increased cardiometabolic risk, and kidney disease is well established. These factors influence the treatment plan, and current treatment options have limited cardiovascular risk reduction. So the need for novel treatments with a broad range of coverage for the complications is warranted. Sodium-glucose co-transporter 2 inhibitors are novel drugs approved for treating type-2 diabetes. They prevent glucose reabsorption and lower serum uric acid levels. Recently few studies have studied their association with reducing the risk of gout. They may help address the gout related complications through their recorded benefit with weight loss, improved insulin resistance, and cardiovascular benefits in recent studies. . SGLT2-Is may be useful to reduce the risk of gout in individuals with type 2 diabetes. Limited literature is available on the safety and efficacy of these novel antidiabetic drugs in patients with gout. This review is aimed to summarize the current knowledge on the role and effectiveness of novel antidiabetic medication as an early therapeutic option in gout patients.

Korelasi Antara Kadar Asam Urat Dalam Darah dan Kristal Asam Urat Dalam Urine Pada Penderita Tuberkulosis Disertai Hiperurisemia

Tuberculosis is a contagious infectious disease caused by the bacteria Mycobacterium tuberculosis. In tuberculosis patients increased levels of uric acid in the blood. Hyperuricemia is the levels of uric acid in the blood that exceeds the normal limits. The research objective in this study was to determine the correlation between the levels of uric acid in the blood and uric acid crystals in the urine in patients with tuberculosis accompanied by hyperuricemia. The research method used in this study was survey analytic with a cross sectional approach. The research used in this study population was all patients with tuberculosis who check in Health Centers of Mataram and samples total of 24 people. Data analysis used a statistical test Spearman Rank correlation. The results showed that levels of uric acid in the blood that is 8.2 mg/dl while on uric acid crystals in urine mean 0.6/fild of view uric acid crystals. The results indicated a correlation between the levels of uric acid in the blood and uric acid crystals in the urine in patients with tuberculosis accompanied by hyperuricemia. The results of the statistical test Rank Spearman showed a p value of 0.041 < 0.05 and the results of the coefficient correlation showed a value -0.419, its mean the strength of the correlation is medium. The conclusion of this study is that the patients with tuberculosis accompanied by hyperuricemia there is a correlation between the levels of uric acid in the blood and uric acid crystals in the urine.

Tailorable Formation of Hierarchical Structure Silica (HMS) and Its Application in Hydrogen Production

Relentless endeavors have been committed to seeking simple structure-directing agents for synthesizing hierarchical mesoporous silica (HMS) materials but remaining challenges. In this contribution, we offered an improved one-pot hydrothermal route to prepare HMS materials using a single non-ionic triblock copolymer (F127) structure-directing agent under a mild polycarboxylic (citric acid) mediated condition. Via studies of key synthetic parameters including acid concentration, crystallization temperature and aging time, it was found that citric acid medium presents an important bridging effect under the optimal concentration from 0.018 M (pH = 2.57) to 1.82 M (pH = 1.09), contributing to the self-assemblage of partially protonated non-ionic triblock copolymer and tetraethyl orthosilicate (TEOS) into a high-quality multistage structure of silica materials. The specific surface area (SSA) of HMS shows a volcanic trend and is closely associated with the concentration of citric acid while the highest SSA of 739.9 m2/g can be achieved at the citric concentration of 0.28 M. Moreover, the as-synthesized HMS-CTA supported Ni/CeO2 catalysts indicate an excellent production of hydrogen through dry reforming of methane (DRM) reaction over 172 h stability. The improved, facile synthesis strategy under polycarboxylic medium displays an expanded perspective for synthesizing other mesoporous materials in a wide range of applications such as catalytic material carriers and drug inhibitors.

In Situ Growth of a Stable Metal-Organic Framework (MOF) on Flexible Fabric via a Layer-by-Layer Strategy for Versatile Applications.

Fabrics have been used broadly in daily life for an enormous variety of applications due to their intrinsic advantages, such as flexibility, renewability, and good processability. Integrating natural fabrics with metal-organic frameworks (MOFs) is an effective strategy to improve the added value of textiles with special functionalities. Here, a facile, low-cost, and scalable technology is reported for the in situ growth of MOFs on cotton fabrics. A uniform and dense coating of regular octahedral Cu-1,3,5-benzenetricarboxylic acid (CuBTC) crystals was formed on the fiber surface, followed by treatment with 1H,1H,2H,2H-perfluorooctyltriethoxysilane and triethoxyoctylsilane to create a superhydrophobic CuBTC@cotton fabric (SMCF), which greatly improved its water stability and extended superhydrophobic CuBTC's potential applications. The as-prepared MCF has a specific surface area of 229 m2/g, which is 11 times that of pristine fabrics (21 m2/g). This high porosity further endows the fabric with enhanced loading capacity of essential oils to enable excellent antibacterial ability. Moreover, the SMCF also exhibits excellent self-cleaning, UV shielding, and anti-icing performances. In addition, we performed COMSOL simulations to investigate the dynamic freezing process of water on the surface of samples, which agrees well with our experimental observations. By combining the merits of both fabrics and MOFs, the MCF is expected to extend the applications of traditional textiles in antifouling, safety, the fragrance industry, and healthcare for the next-generation multifunctional fabrics.

Two concurrent β-variable adaptive model-free controls of a seeded batch crystallizer

The design of an efficient controller for a process of batch crystallization is still an important area of ongoing research. In this paper, a [Formula: see text]-variable adaptive model-free control ([Formula: see text]-AMFC) has been proposed to control a seeded batch adipic acid crystallization process to get a final unimodal crystal size distribution (CSD) within the required mean weight size. The [Formula: see text]-AMFC is developed based on [Formula: see text] online adaptive estimation algorithm to enhance the classic model-free control’s (MFC) performance. It copes with unknown as well as partially known dynamics and the inherent complex behavior of this nonlinear process. The concept consists of using an updated local approximation model. Two structures of [Formula: see text]-AMFC are considered. The first is a [Formula: see text]-AMFC based on intelligent Proportional-Integral ([Formula: see text]-iPI) control and the second is based on intelligent Proportional-Integral control combined with Sliding Mode Control ([Formula: see text]-iPISMC). To obtain the controller parameters of the two [Formula: see text]-AMFC structures, the particle swarm optimization (PSO) method was employed. The comparison of alternative approaches is performed by means of simulations including different scenarios. It is found that the [Formula: see text]-iPISMC has a superior performance: it allows the output convergence 50 minutes earlier than the [Formula: see text]-iPI and it is more robust against any sudden disturbances.

Differences of Uric Acid Transporters Carrying Extracellular Vesicles in the Urine from Uric Acid and Calcium Stone Formers and Non-Stone Formers.

Background: Low urine pH and volume are established risk factors for uric acid (UA) stone disease (UASD). Renal tubular epithelial cells exposed to an acidic pH and/or UA crystals can shed extracellular vesicles (EVs) into the tubular fluid, and these EVs may be a pathogenic biomarker of UASD. Methods: Urinary EVs bearing UA transporters (SLC2A9, SLC17A3, SLC22A12, SLC5A8, ABCG2, and ZNF365) were quantified in urine from UA stone formers (UASFs), calcium stone formers (CSFs), and age-/sex-matched non-stone formers (NSFs) using a standardized and published method of digital flow cytometry. Results: Urinary pH was lower (p < 0.05) and serum and urinary UA were greater (p < 0.05) in UASFs compared with NSFs. Urinary EVs carrying SLC17A3 and SLC5A8 were lower (p < 0.05) in UASFs compared with NSFs. Urinary EVs bearing SLC2A9, SLC22A12, SLC5A8, ABCG2, and ZNF365 were lower (p < 0.05) in CSFs than UASFs, while excretion of SLC17A3-bearing EVs did not differ between groups. Conclusion: EVs bearing specific UA transporters might contribute to the pathogenesis of UASD and represent non-invasive pathogenic biomarkers for calcium and UA stone risk.

A verified open-access AI-based chemical microparticle image database for in-situ particle visualization and quantification in multi-phase flow

Deep learning-based image segmentation and classification had been previously proposed for the in-situ measurement of microcrystal size and shape, which showed great potential to expand as a process analytical technology (PAT) to chemical multi-phase flow processes. In this study, an open-access chemical microparticle image database (open-CMD) was established containing particle agglomerations (A), bubbles (B), crystals (C), and droplets (D) in various chemical multi-phase flow scenarios. The advanced neural network, Mask R-CNN, coupled with 2,500 labeled images containing more than 50,000 labeled particles in open-CMD, was trained to build the ability of target particle segmentation and classification. The training results indicated that a data augmentation strategy could significantly improve the accuracy (<3.8 % average precision) of the trained models, which were named MicropNet+ and MicropNet according to whether the augmented data was used for training or not. Based on the superior capability of MicropNet+, multidimensional particle descriptors were extracted, and further, the degree of agglomeration and agglomeration distribution were defined and quantified. Then, two classical multi-phase flow processes, crystallization and emulsification, were analyzed using the MicropNet+ model, in which the agglomeration degree and distribution (Cin A) of succinic acid crystals and the relative number and diameter (Deq) of droplets were analyzed quantitatively under different operations conditions. It was concluded that the well-trained MicropNet+ model has high accuracy and efficiency in microparticle segmentation and classification. At last, the open-CMD database and the MicropNet+ model were released to inspire potential applications in chemical multi-phase flow areas.

The Correlation Between Uric Acid Levels (Photometer Method) And The Incidence of Hypertension in Prolanis Patients at Puskesmas Klirong II Kebumen Regency

Health service through Prolanis (Program Pengelolaan Penyakit Kronis or Chronic Disease Management Program in English) is a management program for health maintenance in order to achieve an optimal quality of life. One of the targets of prolanis is patients with hypertension. Hypertension can cause the blockage of uric acid crystals in blood vessels so that kidney function is disrupted. As a result, there is an increase in uric acid levels. Based on a preliminary study conducted on March 14, 2022, at Puskesmas Klirong II, it was found that 23 prolanis patients had complaints of joint pain, while 38 of them had hypertension. This research aimed to find out whether there is a correlation between uric acid levels and the incidence of hypertension in prolanis patients at Puskesmas Klirong II. The population was 50 people with a sample of 37 people. The sample was obtained by employing random sampling. This was an Analytical Observational research with a Cross-Sectional research design. The uric acid levels were checked with the Urikase-PAP photometer method. This research was conducted in May 2022. The results showed that 4 respondents had normal uric acid levels and normal blood pressure. On the other hand, there were 12 respondents who had normal uric acid levels and high blood pressure. Meanwhile, the other 21 respondents had high uric acid levels and high blood pressure. The results of the Fisher's Exact Test statistical test obtained a p-value = 0.028 &lt;0.05. It was concluded that there was a correlation between uric acid levels (photometer method) and the incidence of hypertension in prolanis patients at Puskesmas Klirong II, Kabupaten Kebumen.

Electrochemical Preparation of Nanocatalysts and Their Application in Electrocatalysis.

In order to solve the basic problem of high-temperature sintering of molybdenum carbide restricting the efficient construction of molybdenum carbide nanostructures and the full play of hydrogen evolution performance, this article studies the preparation of nano molybdenum carbide/boron nitrogen codoped two-dimensional carbon composite structure catalysts and the electrochemical hydrogen evolution reaction performance. Based on the self-assembly process of gelatin molecules on the surface of a two-dimensional layered boric acid crystal template, a new strategy for constructing a high-performance electrochemical hydrogen evolution reaction catalyst based on molybdenum carbide/boron nitrogen codoped two-dimensional nanocarbon composite structure (η-MoC@ BN-CSs) was established. The experimental results show that the overpotential of hydrogen evolution reaction based on molybdenum carbide/boron nitrogen codoped two-dimensional nanocarbon composite structure catalyst is 159 mV, which is slightly higher than 67 mV of commercial Pt/C catalyst, but lower than the reported literature value in the list. The Tafel slope is 68 mV·dec−1, which is slightly higher than that of the commercial Pt/C catalyst (40 mV·dec−1) and the reference value (58 mV·dec−1), but lower than those of other reported literature values in the list, indicating that the molybdenum carbide/boron nitrogen codoped two-dimensional carbon nanocomposites have excellent catalytic performance under alkaline conditions. Conclusion. This kind of two-dimensional nanocomposite structure shows platinum-like catalytic activity when used as an electrochemical hydrogen evolution catalyst in alkaline electrolyte. It has better reaction kinetics and better stability.

Techno‐economic benchmarking of electrochemically induced succinic acid crystallization

Techno‐economic benchmarking of electrochemically induced succinic acid crystallization

Surface-Enriched Boron-Doped TiO2 Nanoparticles as Photocatalysts for Propene Oxidation.

A series of nanostructured boron-TiO2 photocatalysts (B-X-TiO2-T) were prepared by sol–gel synthesis using titanium tetraisopropoxide and boric acid. The effects of the synthesis variables, boric acid amount (X) and crystallization temperature (T), on structural and electronic properties and on the photocatalytic performance for propene oxidation, are studied. This reaction accounts for the remediation of pollution caused by volatile organic compounds, and it is carried out at low concentrations, a case in which efficient removal techniques are difficult and costly to implement. The presence of boric acid during the TiO2 synthesis hinders the development of rutile without affecting the textural properties. X-ray photoelectron spectroscopy analysis reveals the interstitial incorporation of boron into the surface lattice of the TiO2 nanostructure, while segregation of B2O3 occurs in samples with high boron loading, also confirmed by X-ray diffraction. The best-performing photocatalysts are those with the lowest boron loading. Their high activity, outperforming the equivalent sample without boron, can be attributed to a high anatase and surface hydroxyl group content and efficient photo-charge separation (photoelectrochemical characterization, PEC), which can explain the suppression of visible photoluminescence (PL). Crystallization at 450 °C renders the most active sample, likely due to the development of a pure anatase structure with a large surface boron enrichment. A shift in the wavelength-dependent activity profile (PEC data) and the lowest electron–hole recombination rate (PL data) are also observed for this sample.

Treatment of DEHP-rich PVC waste in subcritical urine wastewater: Efficient dechlorination, denitrification, plasticizer decomposition, and preparation of high-purity phthalic acid crystals

It is difficult to dispose diethylhexyl phthalate-rich polyvinyl chloride (DEHP-rich PVC) waste due to the high level of chlorine and plasticizer. On the other hand, the denitrification of urine wastewater with high nitrogen content also faces great challenges. In this study, a synergistic treatment strategy was developed for the DEHP-rich PVC waste and urine wastewater by a subcritical water process. Subcritical urine wastewater (SUW) was used as a reaction medium in the synergistic treatment. PVC dechlorination, DEHP decomposition, and denitrification of urine wastewater were synchronously achieved in the one pot SUW. Under the optimal conditions (300 °C, 15 min, 1:5 g/mL), the PVC dechlorination ratio, urine wastewater denitrification ratio and DEHP decomposition ratio could reach 98.4%, 64.9%, and 99.2%, respectively. The decomposition of DEHP mainly included hydrolysis, nucleophilic substitution, and acylation. DEHP could be converted into phthalic acid crystal at 220 °C with a yield of 66.25% due to the efficient hydrolysis action of SUW. All the removed Cl was transferred from PVC matrix to aqueous phase. Hydroxyl nucleophilic substitution is the principal dechlorination path of PVC. The reactions between N-containing species and DEHP in SUW resulted in the high-efficiency denitrification of urine wastewater, and the N element was fixed in solid residue or transferred to oil phase as amides compounds. It is believed that the proposed SUW process is a promising technology for the synergistic treatment of DEHP-rich PVC waste and urine wastewater.

Consumption of soft drinks rich in phosphoric acid versus struvite crystallization from artificial urine

In recent years, there has been a continuous increase in the incidence of urolithiasis, especially in highly developed countries. Therefore, the question arises which factors specific to these countries may be responsible for the increase in the incidence of this disease. In this article, we try to assess the effect of phosphoric acid, a component of various carbonated drinks, including Coca-Cola, on the nucleation and growth of struvite crystals, which are the main component of infectious urinary stones. The research was carried out in the environment of artificial urine with and without the presence of Proteus mirabilis bacteria. In the latter case, the activity of bacterial urease was simulated by adding an aqueous ammonia solution. The obtained results indicate that phosphoric acid present in artificial urine causes the nucleation of struvite to shift towards a lower pH, which means that struvite nucleates earlier in artificial urine compared to the control test. The amount of struvite formed is the greater the higher the concentration of phosphoric acid. At the same time, as the concentration of phosphoric acid increases, the growing struvite crystals are larger, which is disadvantageous because they are more difficult to remove from the urinary tract along with the urine. For the highest levels of phosphoric acid tested, large dendrites are formed, which are particularly undesirable as they can damage the epithelium of the urinary tract. The effect of phosphoric acid on the nucleation and growth of struvite is explained in base of chemical speciation analysis. This analysis indicates that the MgHCit and MgCit− complexes have the main influence on the nucleation and growth of struvite in artificial urine in the presence of phosphoric acid. It should be keep in mind that all these effects of phosphoric acid are possible when the urinary tract is infected with urease-positive bacteria. In the absence of infection, phosphoric acid will not cause struvite to crystallize.