Structured Catalysts and Catalytic Processes: Transport and Reaction Perspectives.

The structure of catalysts determines the performance of catalytic processes. Intrinsically, the electronic and geometric structures influence the interaction between active species and the surface of the catalyst, which subsequently regulates the adsorption, reaction, and desorption behaviors. In recent decades, the development of catalysts with complex structures, including bulk, interfacial, encapsulated, and atomically dispersed structures, can potentially affect the electronic and geometric structures of catalysts and lead to further control of the transport and reaction of molecules. This review describes comprehensive understandings on the influence of electronic and geometric properties and complex catalyst structures on the performance of relevant heterogeneous catalytic processes, especially for the transport and reaction over structured catalysts for the conversions of light alkanes and small molecules. The recent research progress of the electronic and geometric properties over the active sites, specifically for theoretical descriptors developed in the recent decades, is discussed at the atomic level. The designs and properties of catalysts with specific structures are summarized. The transport phenomena and reactions over structured catalysts for the conversions of light alkanes and small molecules are analyzed. At the end of this review, we present our perspectives on the challenges for the further development of structured catalysts and heterogeneous catalytic processes.

Highly selective NH3 synthesis from N2 on electron-rich Bi0 in a pressurized electrolyzer.

Electrochemical conversion of N2 into ammonia presents a sustainable pathway to produce hydrogen storage carrier but yet requires further advancement in electrocatalyst design and electrolyzer integration. This technology suffers from low selectivity and yield owing to the extremely strong N≡N bond and the exceptionally low solubility of N2 in aqueous systems. A high NH3 synthesis performance is restricted by the high activation energy of N≡N bond and the supply insufficiency of N2 to active sites. This paper describes the introduction of electron-rich Bi0 sites into Ag catalysts with a high-pressure electrolyzer that enables a dramatically enhanced Faradaic efficiency of 44.0% and yield of 28.43 µg cm-2 h-1 at 4.0 MPa. Combined with density functional theory results, in situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy demonstrates that N2 reduction reaction follows an associative mechanism, in which a high coverage of N-N bond and -NH2 intermediates suggest electron-rich Bi0 boosts sound activation of N2 molecules and low hydrogenation barrier. The proposed strategy of engineering electrochemical catalysts and devices provides powerful guidelines for achieving industrial-level green ammonia production.

International Alliance of Urolithiasis (IAU) guideline on staghorn calculi management.

BACKGROUND: The stone burden based management strategy reported in the guidelines published by different associations is well known for a long time. Staghorn calculi, representing the largest burden and most complex stones, is one of the most challenging cases to practicing urologists in clinical practice. The International Alliance of Urolithiasis (IAU) has released a series of guidelines on the management of urolithiasis. PURPOSE: To develop a series of recommendations for the contemporary management management of staghorn calculi and to provide a clinical framework for urologists treating patients with these complex stones. METHODS: A comprehensive literature search for articles published in English between 01/01/1976 and 31/12/2022 in the PubMed, OVID, Embase and Medline database is performed. A series of recommendations are developed and individually graded following the review of literature and panel discussion. RESULTS: The definition, pathogenesis, pathophysiology, preoperative evaluation, intraoperative treatment strategies and procedural advice, early postoperative management, follow up and prevention of stone recurrence are summarized in the present document. CONCLUSION: A series of recommendations regarding the management of staghorn calculi, along with related commentary and supporting documentation offered in the present guideline is intended to provide a clinical framework for the practicing urologists in the management of staghorn calculi.

Mesenchymal stem cell-derived exosomes promote tissue repair injury in rats with liver trauma by regulating gut microbiota and metabolism.

OBJECTIVE: The effects of mesenchymal stem cells (MSCs) and MSC-derived exosomes (MSC-exos) on serum metabolites and intestinal microbiota in rats after liver trauma were discussed. METHODS: Adult Wistar Albino rats were assigned into control, model (liver trauma), MSCs, and MSC-exos groups (n = 6). The study examined changes in the inflammatory environment in liver tissues were analyzed by histological examination and analysis of macrophage phenotypes. Alterations in serum metabolites were determined by untargeted metabonomics, and gut microbiota composition was characterized by 16S rDNA sequencing. Correlations between specific gut microbiota, metabolites, and inflammatory response were calculated using Spearman correlation analysis. RESULTS: Rats with liver trauma after MSCs and MSC-exos treatment exhibited attenuated inflammatory infiltration and necrosis in liver tissues. MSCs and MSC-exos treatment reduced the proportion of M1 macrophages, accompanied by a decrease in inducible nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-α) levels. Furthermore, MSCs and MSC-exos treatment expanded the proportion of M2 macrophages, accompanied by an increase in arginase-1 (Arg-1) and interleukin-10 (IL-10) levels. The beneficial effects of MSC-exo treatment on rats with liver trauma were superior to those of MSC treatment. The composition and abundance of the gut microbiota and metabolites were altered in pathological rats, whereas MSC and MSC-exo intervention partially restored specific gut microbiota and metabolite alterations. At the phylum level, alterations in Bacteroidota, Proteobacteria, and Verrucomicrobiota were observed after MSC and MSC-exo intervention. At the genus level, Intestinimonas, Alistipes, Aerococcus, Faecalibaculum, and Lachnospiraceae_ND3007_group were the main differential microbiota. 6-Methylnicotinamide, N-Methylnicotinamide, Glutathione, oxidized, ISOBUTYRATE, ASCORBATE, EICOSAPENTAENOATE, GLYCEROL 3-PHOSPHATE, and Ascorbate radical were selected as important differential metabolites. There was a clear correlation between Ascorbate, Intestinimonas/Faecalibaculum and inflammatory cytokines. CONCLUSION: MSC-exos promoted the repair of tissue damage in rats with liver trauma by regulating serum metabolites and intestinal microbiota, providing new insights into how MSC-exos reduced inflammation in rats with liver trauma.

Modulation of *CHxO Adsorption to Facilitate Electrocatalytic Reduction of CO2 to CH4 over Cu-Based Catalysts.

Copper (Cu) can efficiently catalyze the electrochemical CO2 reduction reaction (CO2RR) to produce value-added fuels and chemicals, among which methane (CH4) has drawn attention due to its high mass energy density. However, the linear scaling relationship between the adsorption energies of *CO and *CHxO on Cu restricts the selectivity toward CH4. Alloying a secondary metal in Cu provides a new freedom to break the linear scaling relationship, thus regulating the product distribution. This paper describes a controllable electrodeposition approach to alloying Cu with oxophilic metal (M) to steer the reaction pathway toward CH4. The optimized La5Cu95 electrocatalyst exhibits a CH4 Faradaic efficiency of 64.5%, with the partial current density of 193.5 mA cm-2. The introduction of oxophilic La could lower the energy barrier for *CO hydrogenation to *CHxO by strengthening the M-O bond, which would also promote the breakage of the C-O bond in *CH3O for the formation of CH4. This work provides a new avenue for the design of Cu-based electrocatalysts to achieve high selectivity in CO2RR through the modulation of the adsorption behaviors of key intermediates.

Lactobacillus casei combined with Lactobacillus reuteri alleviate pancreatic cancer by inhibiting TLR4 to promote macrophage M1 polarization and regulate gut microbial homeostasis.

BACKGROUND: Pancreatic cancer is a highly lethal disease with no effective treatments. Lactobacillus casei (L. casei) and Lactobacillus reuteri (L. reuteri) exhibited therapeutic effects on several cancers, but their roles in pancreatic cancer are unknown. This study aims to explore how L. casei & L. reuteri influence pancreatic cancer and the underlying mechanisms. METHODS: Pancreatic cancer cells were treated with L. casei & L. reuteri and co-cultured with macrophages in a transwell system in vitro. Pancreatic cancer xenograft model was established and L. casei & L. reuteri was used to treat mice in vivo. MTT, CCK-8 assay or immunohistochemical staining were used to determine the proliferation of pancreatic cancer cells or tumor tissues. Transwell assay was applied to test the migration and invasion of pancreatic cells. RT-qPCR was utilized to assess TLR4 and MyD88 expressions in pancreatic cells or tumor tissues. WB, immunofluorescence staining, or flow cytometry was used to evaluate the M1/M2 polarization of macrophages. Besides, the composition of gut microbiota of tumor-bearing mice was determined by 16 S rRNA sequencing, and ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) untargeted metabolomics was used to evaluate the metabolic profiles of feces. RESULTS: L. casei & L. reuteri inhibited the proliferation, migration, invasion of pancreatic cancer cells and pancreatic cancer cell-induced M2 polarization of macrophages by suppressing TLR4. Meanwhile, L. casei & L. reuteri repressed pancreatic cancer growth and promoted M1 macrophage polarization. Besides, L. casei & L. reuteri reduced fecal Alloprevotella and increased fecal azelate and glutamate in nude mice, while TLR4 inhibitor TAK-242 increased Clostridia UCG-014, azelate, uridine, methionine sulfoxide, oxypurinol, and decreased glyceryl monoester in the feces of pancreatic tumor-bearing mice. Fecal oxypurinol and glyceryl monoester levels were positively or negatively associated with gut Clostridia UCG-014 abundance, respectively. CONCLUSION: L. casei & L. reuteri alleviate pancreatic cancer by inhibiting TLR4 to promote macrophage M1 polarization and regulate gut microbial homeostasis.

First Report of Phytophthora infestans Causing Late Blight on Pepino (Solanum muricatum) in China.

Solanum muricatum, known as pepino or melon pear, is a species of evergreen shrub grown for its sweet edible fruits, which was introduced in Yunnan about 20 years ago. Since 2019 to now, serious blight disease was observed on foliages, haulms and fruits of pepino plants in Shilin (25°N, 103°E), which is the biggest pepino production area in China. The symptomatic blighted plants showed water-soaked and brown foliar lesions, haulm brown necrosis, black-brown and rotting fruits, and overall plant decline. The samples with typical disease symptoms were collected for pathogen isolation. After surface sterilization, disease samples were cut into small pieces and placed on rye sucrose agar medium amended with both 25 mg/liter rifampin and 50 mg/liter ampicillin, then incubated in the dark at 25℃ for 3 to 5 days. White fluffy colonies of mycelia that grew from the edge of diseased tissues were further purified and subcultured on rye agar plates. All purified isolates were identified as Phytophthora spp. based on morphological characteristics (Fry 2008). Sporangiophores were nodular and sympodial branches with swellings at the points where sporangia were attached. Sporangia that were hyaline and the average size were 22×40 µm were formed on the tip of sporangiophores and appeared as subspherical, ovoid, ellipsoid or lemon shaped with half-papillate on the spire. Mature sporangia were easilly detached from sporangiophores. For pathogenicity tests, healthy leaves, haulms and fruits of pepino were inoculated with 1×104 cfu/ml zoospore suspension of Phytophthora islolate (RSG2101), and controls were treated with sterile distilled water, respectively. After 5 to 7 days postinoculation, all Phytophthora-inoculated leaves and haulms showed water-soaked and brown lesions with white mold layer, fruits showed dark-brown firm lesions which got expanded and rotted the entire fruit. The symptoms were same as those occurred in natural fields. In contrast, no disease symptoms appeared in the control tissues. Phytophthora isolates could be reisolated and showed same morphological characteristics from the infected tissues of leaves, haulms, and fruits, sufficing Koch's postulates. Two common molecular targets of the internal transcribed spacer (ITS) region of ribosomal DNA and partial cytochrome c oxidase subunit II (CoxII) of the Phytophthora isolate (RSG2101) were amplified and sequenced with primers ITS1/ITS4 and FM75F/FM78R (Kroon et al. 2004). The ITS and CoxII sequence data were deposited in GenBank under accession numbers OM671258 and OM687527, respectively. Blastn analysis of both ITS and CoxII sequences showed 100% identity with isolates of P. infestans (MG865512, MG845685, AY770731 and DQ365743, respectively). Phylogenetic analysis also indicated that RSG2101 isolate and known P. infestans isolates localized in the same evolutionary branch based on sequences of ITS and CoxII, respectively. Based on these results, the pathogen was identified as P. infestans. It is known that P. infestans infection of pepino occurrs in Latin America and then it was recorded in other parts of the world such as New Zeeland and India (Hill, 1982; Abad and Abad,1997; Mohan et al. 2000).To our knowledge, this is the first report of late blight on pepino caused by P. infestans in China, which will be helpful to develop efficient blight management strategies on pepino.

First Report of Globisporangium spinosum Causing Root Rot of Panax notoginseng in China.

Panax notoginseng (Burkill) F.H. Chen, known as ''sanqi'', is widely used for its medicinal and tonic effects in China, such as treatment of cardiovascular diseases and antioxidant effects. However, root rot disease is the most destructive disease that hampers industrial development (Mi et al. 2017). In August 2018 and 2019, samples displaying symptoms of root rot, such as unnormal, stunted growth and chlorotic leaves, were dug out with a shovel and put in clean sample-bags from four production bases in Wenshan (around 23.5° N; 104° E), Yunnan province, the biggest "sanqi" production area in China, with over 20 thousand ha. Among production bases, root rot incidence typically ranged from 10% to 20%, but in a few number of severe cases, exceeded 70%. Typical symptomatic root tubers were washed with tap water, surface-sterilized in 5% NaClO for 1 min followed by 70% alcohol for 30 s, and rinsed three times with sterile water. The diseased tissues were excised and placed on rye sucrose agar medium (RSA) supplemented with 25 mg/L rifampin and 50 mg/L kanamycin, then incubated at 25°C in the dark for five days. Colonies with different features grew from the diseased pieces and twenty oomycete-like colonies, (white, dense, aerial mycelia with rapid radiate growth) were chosen for further investigation. Microscopic observations showed terminal and intercalary hyphal swellings, which were either globose or limoniform, thin-walled, mostly smooth, and 13-28 µm wide (average 20.3 µm). Oogonia were globose or rarely fusiform, mostly intercalary, 11-19 µm wide (average 13 µm), provided with a varying number of blunt, digitate projections. Oospores were plerotic, rarely aplerotic, thin-walled, and 16-19 µm wide (average 18.6 µm). Antheridia usually originated at various distances from the oogonium and appeared- clavate and crook-necked, making apical contact with the oogonium. Based on typical morphological features described, the isolates were putatively identified as Pythium spinosum (van der Plaats-Niterink 1981). The internal transcribed spacer region (ITS) and cytochrome c oxidase subunit II (CoxII) of isolates SQ00803 and SQ00903-1 were sequenced using universal primers ITS1/ITS4 and FM58/FM66 (Villa et al. 2006). The nucleotide sequences were deposited to GenBank with the accession numbers MN369530, MN370548, MN561687 and MN561688, respectively. Blastn analysis of ITS sequences showed 99.58% similarity to those of Globisporangium spinosum isolates CBS275.67 and CBS276.67 (accession number AY598701 and HQ643792). CoxII sequences showed 99.82% to 100% similarity to G. spinosum isolates (accession number GU071755 and AF196616). For pathogenicity tests, nine two-year-old healthy sanqi plants grown in sterilized substrate in plastic pots under greenhouse conditions were inoculated with 5×104 CFU/ml zoospore suspension of G. spinosum by root-drenching method (Dixon et al. 1984). Three non-inoculated plants drenched with sterile water were used as controls. All plants were incubated in a growth chamber at 25°C with a 16/8-h photoperiod. After two weeks, inoculated sanqi plants showed discoloration and chlorosis of leaves with water-soaked root rot. Control plants were symptomless and healthy. Colonies resembling G. spinosum were re-isolated from infected root tissues and showed the same morphological features as G. spinosum, thus fulfilling Koch's postulates. G. spinosum originally isolated from seedlings of Anthirrhinum majus has been reported to cause root rot disease on many plant species worldwide (Lévesque and De Cock 2004). Recently, based on whole genome sequencing and phylogenomic analysis, P. spinosum was transferred to Globisporangium genus. Therefore, P. spinosum is now classified as G. spinosum (Hai et al. 2022). To our knowledge, this is the first report of G. spinosum causing root rot of P. notoginseng in China. This research will contribute to the development of integrated management strategies for P. notoginseng root rot.

High-Throughput Screening of Electrocatalysts for Nitrogen Reduction Reactions Accelerated by Interpretable Intrinsic Descriptor.

Developing easily accessible descriptors is crucial but challenging to rationally design single-atom catalysts (SACs). This paper describes a simple and interpretable activity descriptor, which is easily obtained from the atomic databases. The defined descriptor proves to accelerate high-throughput screening of more than 700 graphene-based SACs without computations, universal for 3-5d transition metals and C/N/P/B/O-based coordination environments. Meanwhile, the analytical formula of this descriptor reveals the structure-activity relationship at the molecular orbital level. Using electrochemical nitrogen reduction as an example, this descriptor's guidance role has been experimentally validated by 13 previous reports as well as our synthesized 4 SACs. Orderly combining machine learning with physical insights, this work provides a new generalized strategy for low-cost high-throughput screening while comprehensive understanding the structure-mechanism-activity relationship.

The protective effects of NE 52-QQ57 against interleukin-33-induced inflammatory response in activated synovial mast cells.

Cytokines-mediated immunity is essential for the pathological development of rheumatoid arthritis (RA). Inhibition of signaling has suggested a potential remedial approach to RA. G protein-coupled receptor 4 (GPR4) has been proven to possess a broad range of physiological functions, but its function in synovial mast cells and RA is less reported. In this study, the protective effects of NE 52-QQ57, a GPR4 antagonist, against interleukin (IL)-33-challenged inflammatory response in activated synovial mast cells were investigated. We report that IL-33 amplified GPR4 expression in HMC-1 mast cells. The GPR4 antagonist NE 52-QQ57 alleviated IL-33-caused secretions of IL-17, interferon-γ, and tumor necrosis factor-α in HMC-1 mast cells. Furthermore, we note that NE 52-QQ57 reduced IL-33-induced expressions of matrix metalloproteinase-2 (MMP-2) and MMP-9. Also, NE 52-QQ57 inhibited cyclooxygenase 2 and prostaglandin E2 expression in IL-33-challenged cells. Also, NE 52-QQ57 ameliorated IL-33-induced oxidative stress by reducing mitochondrial reactive oxygen species and 4-hydroxynonenal. Mechanistically, NE 52-QQ57 mitigated IL-33-induced activation of the p38/nuclear factor-κB signaling pathway. We conclude that targeting GPR4 might be a promising strategy for RA treatment.

Modeling CoCu Nanoparticles Using Neural Network-Accelerated Monte Carlo Simulations.

The correct description of catalytic reactions happening on bimetallic particles is not feasible without proper accounting of the segregation process. In this study, we tried to shed light on the structure of large CoCu particles, for which quite controversial results were published before. However, density functional theory (DFT) is challenging to be directly used for the systematic study of nanometer-sized particles. Therefore, we constructed a neural network-based potential and further applied it to the Monte Carlo simulations for the description of the segregation phenomenon. The resulting approach shows high efficiency and can be used in systems with thousands of atoms. The accuracy and transferability of the model to other sizes and compositions make this methodology useful for solving segregation problems.

Arctiin-reinforced antioxidant microcarrier antagonizes osteoarthritis progression.

Loss of extracellular matrix (ECM) of cartilage due to oxidative stress injury is one of the main characteristics of osteoarthritis (OA). As a bioactive molecule derived from the traditional Chinese Burdock, arctiin exerts robust antioxidant properties to modulate redox balance. However, the potential therapeutic effects of arctiin on OA and the underlying mechanisms involved are still unknown. Based on the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) tool, Burdock-extracted small molecule arctiin was identified as a potential anti-arthritic component. In vitro, treatment using arctiin rescued the interleukin (IL)-1ß-induced activation of proteinases and promoted the cartilage ECM synthesis in human chondrocytes. In vivo, intraperitoneal injection of arctiin ameliorated cartilage erosion and encountered subchondral bone sclerosis in the post-traumatic OA mice. Transcriptome sequencing uncovered that arctiin-enhanced cartilage matrix deposition was associated with restricted oxidative stress. Mechanistically, inhibition of nuclear factor erythroid 2-related factor 2 (NRF2) abolished arctiin-mediated anti-oxidative and anti-arthritic functions. To further broaden the application prospects, a gellan gum (GG)-based bioactive gel (GG-CD@ARC) encapsulated with arctiin was made to achieve long-term and sustained drug release. Intra-articular injection of GG-CD@ARC counteracted cartilage degeneration in the severe (12 weeks) OA mice model. These findings indicate that arctiin may be a promising anti-arthritic agent. Furthermore, GG-modified bioactive glue loaded with arctiin provides a unique strategy for treating moderate to severe OA.

Data-Driven Interpretable Descriptors for the Structure-Activity Relationship of Surface Lattice Oxygen on Doped Vanadium Oxides.

Understanding the structure-activity relationship of surface lattice oxygen is critical but challenging to design efficient redox catalysts. This paper describes data-driven redox activity descriptors on doped vanadium oxides combining density functional theory and interpretable machine learning. We corroborate that the p-band center is the most crucial feature for the activity. Besides, some features from the coordination environment, including unoccupied d-band center, s- and d-band fillings, also play important roles in tuning the oxygen activity. Further analysis reveals that data-driven descriptors could decode more information about electron transfer during the redox process. Based on the descriptors, we report that atomic Re- and W-doping could inhibit over-oxidation in the chemical looping oxidative dehydrogenation of propane, which is verified by subsequent experiments and calculations. This work sheds light on the structure-activity relationship of lattice oxygen for the rational design of redox catalysts.

Moderate Surface Segregation Promotes Selective Ethanol Production in CO2 Hydrogenation Reaction over CoCu Catalysts.

Cobalt-copper (CoCu) catalysts have industrial potential in CO/CO2 hydrogenation reactions, and CoCu alloy has been elucidated as a major active phase during reactions. However, due to elemental surface segregation and dealloying phenomena, the actual surface morphology of CoCu alloy is still unclear. Combining theory and experiment, the dual effect of surface segregation and varied CO coverage over the CoCu(111) surface on the reactivity in CO2 hydrogenation reactions is explored. The relationship between C-O bond scission and further hydrogenation of intermediate *CH2 O was discovered to be a key step to promote ethanol production. The theoretical investigation suggests that moderate Co segregation provides a suitable surface Co ensemble with lateral interactions of co-adsorbed *CO, leading to promoted selectivity to ethanol, in agreement with theory-inspired experiments.

Nature of the Active Sites of Copper Zinc Catalysts for Carbon Dioxide Electroreduction.

The electrochemical CO2 reduction (CO2 ER) to multi-carbon chemical feedstocks over Cu-based catalysts is of considerable attraction but suffers with the ambiguous nature of active sites, which hinder the rational design of catalysts and large-scale industrialization. This paper describes a large-scale simulation to obtain realistic CuZn nanoparticle models and the atom-level structure of active sites for C2+ products on CuZn catalysts in CO2 ER, combining neural network based global optimization and density functional theory calculations. Upon analyzing over 2000 surface sites through high throughput tests based on NN potential, two kinds of active sites are identified, balanced Cu-Zn sites and Zn-heavy Cu-Zn sites, both facilitating C-C coupling, which are verified by subsequent calculational and experimental investigations. This work provides a paradigm for the design of high-performance Cu-based catalysts and may offer a general strategy to identify accurately the atomic structures of active sites in complex catalytic systems.

Synergistic Mechanism of Platinum-GaOx Catalysts for Propane Dehydrogenation.

The synergy between metals and metal oxides can effectively improve the heterogeneous catalytic process. This paper describes the intrinsic effect of Pt modification over GaOx (Pt-GaOx ) on propane dehydrogenation. The presence of Pt promotes H2 dissociation and surface coverage of hydrogen species, which is beneficial for the activation of C-H in propane. With excessive Pt, Gaδ+ can be further reduced to form Pt-Ga alloy with less surface hydrogen species. Consequently, the relative propylene formation rate between Pt-GaOx and the summed contribution of individual Pt and GaOx increases linearly with the content of hydrogen species. Optimally, the relative propylene formation rate of Pt-GaOx with 0.03 wt % Pt exceeds 25 % of the summed contribution of individual components.

Glycine suppresses kidney calcium oxalate crystal depositions via regulating urinary excretions of oxalate and citrate.

An abnormal urine composition is a key reason for kidney stone formation, but little is known about the roles of small metabolites in the urine during kidney stone formation. Here, we found urine glycine in patients with kidney calcium oxalate (CaOx) stone was significantly lower than that in healthy people via 1 H NMR spectra detection, and investigated the role and underlying mechanism of glycine in the regulation of CaOx stone formation. Our results showed that glycine could significantly attenuate ethylene glycol-induced CaOx crystal depositions in rat kidney via decreasing urine oxalate and increasing urine citrate. Mechanism studies revealed that glycine could decrease urine oxalate through downregulating Slc26a6 expression, whereas increase urine citrate via inhibiting Nadc1 expression. Moreover, glycine decreased the protein expression of both Slc26a6 and Nadc1 via increasing the expression of miRNA-411-3p, which directly bound to the 3'-untranslated regions of Slc26a6 and Nadc1 messenger RNAs, in vitro and in vivo. Together, our results revealed a novel role of glycine in the regulation of kidney CaOx crystal formation and provided a potential target for the treatment of kidney CaOx stone.

The impact of nephrostomy drainage prior to mini-percutaneous nephrolithotomy in patients with ESBL-positive Escherichia coli.

OBJECTIVE: Extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-EC) is one of the most frightening multidrug-resistant bacteria that usually causes sepsis. Herein we explored the benefits of nephrostomy drainage prior to percutaneous nephrolithotomy (PCNL) on infection outcomes in patients with ESBL-EC. PATIENTS AND METHODS: Between June 2016 and April 2019, 43 consecutive patients with ESBL-EC who received nephrostomy drainage for > 24 h prior to PCNL were retrospectively evaluated as group 1. 86 patients were randomly selected from patients with ESBL-EC who received concurrent percutaneous access during PCNL as group 2. The postoperative infection complications were compared. RESULTS: Although the total infection complications were not statistically different (11.6% vs. 25.6%, p = 0.066), the severity seemed to be worse among group 2 subjects. Severe infections, including urosepsis (4.7% vs.13.9%) and septic shock (2.3% vs 4.6%), were observed at twice or greater rates in group 2. Blood transfusions were also more frequent (2.3% vs. 13.9%, p = 0.039). Multivariate analysis demonstrated that preoperative drainage was an independent risk factor for postoperative infection events (OR 2.31 CI 1.14-3.48, p = 0.017). Subgroup analyses indicated that preoperative drainage may largely reduce the incidence of urosepsis in patients with hydronephrosis or without receiving preoperative carbapenem therapy. CONCLUSION: Because of the high rate of severe infection after PCNL in patients with ESBL­positive E. coli, preoperative nephrostomy drainage for > 24 h is an effective measure to reduce the risk of severe infection complications, especially in patients with hydronephrosis or those without preoperative carbapenem therapy.

Association between hypertension and 24-h urine composition in adults without urolithiasis in China.

PURPOSE: To explore the association between hypertension and 24-h urine composition in adults without urolithiasis in China. MATERIALS AND METHODS: Blood test and 24-h urine analysis were performed on 958 non-stone formers in six cities to select eligible participants. Eligible participants were divided into hypertension group and non-hypertension group according to WHO guidelines. The 24-h urine compositions between two groups were compared using univariate and multivariate logistic regressions. RESULTS: A total of 584 adults without urolithiasis were included in this analysis. Compared with non-hypertension group, hypertension group had significantly older age, higher BMI, higher prevalence of diabetes mellitus and higher levels of total cholesterol and LDL, but lower eCCr value, lower levels of serum creatinine and serum sodium (all P value < 0.05). In univariable comparisons, hypertension patients had significantly higher level of urine potassium (mean difference [MD] = - 3.89 mmol, 95% confidence interval [CI] - 7.37 to - 0.42, P = 0.014) but lower levels of urine creatinine (MD = 0.80 mmol, 95% CI 0.21-1.39, P = 0.004) and pH (MD = 0.12, 95% CI - 0.01 to 0.25, P = 0.033) than non-hypertension adults. However, no significant difference was found in all 24-h urinary components between two groups (all P value > 0.05) in multivariate Logistic regression analyses. CONCLUSIONS: Our study demonstrated that hypertension did not independently influence the 24-h urine composition in adults without urolithiasis in China; however, we cannot make such an arbitrary conclusion that hypertension was not a risk factor for urolithiasis.

Is multiple tract percutaneous nephrolithotomy a safe approach for staghorn calculi?

PURPOSE: To explore the safety of multiple tract percutaneous nephrolithotomy (PNL) in terms of complication and draw a nomogram to predict the possibility of significant renal function decline (SRFD). MATERIALS AND METHODS: Patients with complex renal calculi appropriate for PNL at our institution between August 2016 and February 2018 were included in the study. The outcome of single and multiple tract PNL was analyzed retrospectively. A nomogram was created to predict the probability of SRFD. RESULTS: 793 (88.4%) patients were treated with single tract PNL (Group 1) and 104 patients (11.6%) treated with multiple tract PNL (Group 2). Group 2 had a significantly greater hemoglobin reduction (16.0 ± 12.5 vs. 11.4 ± 11.8 g/L, p < 0.001), higher rate of postoperative fever (19.2% vs. 11.9%, p = 0.034) and longer duration of the operation (110.6 ± 39.6 vs. 97.8 ± 34.5 min, p < 0.001). A nomogram for predicting the probability of SRFD was constructed based on identified risk factors: patients' age, positive urine culture (UC +), hemoglobin reduction and embolization. The area of receiver operating characteristic (ROC) curve was 70%. Bootstrapping technique utilized to make the calibration plot showed a high reliability of the nomogram. CONCLUSIONS: Multiple tract PNL had a higher risk of hemoglobin reduction and postoperative fever than single tract PNL. Multiple tracts had no effect on SRFD, but old age, UC + , hemoglobin reduction and embolization were risk factors for SRFD. A nomogram with the aim of predicting the probability of SRFD based on these parameters demonstrated good uniformity in internal validation.