Petroleum wastewater: Environmental protection, treatment, and safe reuse: An overview.

Oil petroleum production consumes about 1.0-7.2 bbl. The needed water for such production ranges between 0.47 and 7.2 L water to 1.0 L crude. Between 80 and 90% of the consumed water is disposed of as wasted effluents. Consequently, there is an important connection between petroleum production and the contamination of the environment and surface water in addition to their ecotoxicological effects. The objective of the present review is to through light on the hazardous impact of petroleum wastewater on the environment and water ways. The present study presents several wastewater treatment technologies in handling the petroleum produced water (PPW) and reducing the hazardous impact to the environment. Safe reuse is also presented including simple, advanced, and environmentally friendly techniques. The reported treatment technologies are divided into five main categories: membrane technologies, biological treatment processes, electro-chemical coagulation, physical/chemical treatment processes (dissolved air flotation (DAF)/air flotation (IAF), adsorption, and chemical flocculation), and catalytic oxidation including chemicals such as advanced and Fenton oxidation processes (AOPs). The analysis and observation of each treatment process are also presented. Implementing of these processes in sequential and/or in combined to avoid the drawbacks of any poor treatment are discussed. The present review discusses; also, in detail each of these treatment technologies and their efficiency including the observation and conclusions of each one. The study shows; also; how the final treated effluent can be reused for non-potable purposes as an additional water resource according to the degree of decontamination. An additional advantage of treatment is protection of both the environment and the water ways by avoiding any discharge of such hazardous wastewater.

Identification and characterization of a recombinant cysteine peptidase (AsCathL) from leaf-cutting ant Atta sexdens Linnaeus, 1758 (Hymenoptera, Formicidae).

Cysteine peptidases are involved in physiological processes of insect development and have been considered as potential targets for the development of insect control strategies. In this study, we obtained a recombinant cysteine cathepsin L (AsCathL) from leaf-cutting ant (Atta sexdens), a species from the order Hymenoptera who causes enormous damage to crops, natural forests and reforested areas. RT-qPCR showed AsCathL expression throughout insect development and in all body parts of the adult insect analysed, suggesting its role as a lysosomal cathepsin. AsCathL encodes a protein of 320 amino acid residues consisting of a pro-peptide and the mature with amino acids sequence over 67% similarity with lysosomal cathepsin L of species from Lepidoptera and Diptera. Phylogenetic tree revealed that AsCathL is very similar to predicted cathepsins found in other ants. Recombinant AsCathL was expressed in insoluble form by Escherichia coli Arctic Express (DE3) RIL, purified under denaturing conditions and refolded. The enzyme showed hydrolytic activity in vitro towards synthetic substrate Z-Phe-Arg-AMC at acidic pH. Synthetic inhibitor E-64 acted against peptidase activity and a study regarding the interaction between E-64 and AsCathL using nuclear magnetic resonance (NMR) revealed that 83.18% from all E-64 molecules are irreversibly bound to AsCathL. In addition, the proteolytic activity of AsCathL was strongly inhibited by recombinant sugarcane cystatins with Ki ranging from 0.6 nM to 2.95 nM. To the best of our knowledge this is the first report characterizing a cysteine peptidase from leaf-cutting ants, which may contribute to future studies of ants' cathepsins.

Rehabilitation Posture Does Not Affect the Outcome of Arthroscopically Treated Acromioclavicular Dislocation.

PURPOSE: To assess the effect of the patient's posture (erect or supine) during rehabilitation sessions on pain, function, and the coracoclavicular (CC) distance after arthroscopic treatment of acromioclavicular joint dislocation. METHODS: Sixty patients with acute type III or V acromioclavicular dislocation injuries were randomly allocated into 2 groups according to their posture during the rehabilitation phase: supine rehabilitation group (SRG) or erect rehabilitation group (ERG). Arthroscopic stabilization with a suspensory fixation device was used in all patients. The visual analog scale (VAS) score was assessed on the first postoperative day and at 1, 3, and 6 months postoperatively. The Constant-Murley score (CMS) was recorded preoperatively and at 3, 6, 12, and 24 months postoperatively. The CC distance was assessed preoperatively; on the first postoperative day; and at 6, 12, and 24 months postoperatively. RESULTS: No significant differences were found between the 2 groups in terms of the VAS score, CMS, and CC distance changes. A significant improvement over the follow-up phase was identified in the VAS score and CMS in both groups. The CC distance in both groups was significantly reduced from preoperatively (29.34 mm in the ERG and 28.65 mm in the SRG) to the first postoperative day (10.44 mm and 10.11 mm, respectively). However, a statistically significant re-widening of the CC distance (P < .001) occurred within the first 6 months after surgery (13.55 mm in the ERG and 13.50 mm in the SRG) and at 12 months (15.51 mm and 15.80 mm, respectively). CONCLUSIONS: The patient's posture during early postoperative rehabilitation does not affect the CC distance changes. LEVEL OF EVIDENCE: Level I, randomized prospective comparative study.

Clinico-pathological and prognostic implications of Srx, Nrf2, and PROX1 expression in gastric cancer and adjacent non-neoplastic mucosa - an immunohistochemical study.

INTRODUCTION: Sulfiredoxin (Srx), which is an endogenous antioxidant substance which could, regulate the signaling pathways of reactive oxygen species. Nuclear factor erythroid 2-related factor 2 (Nrf2) is Cap-N-collar (CNC) transcription factors family member that have essential roles in regulation of antioxidant response. The transcription factor PROX1 is a transcription factor and a key regulatory protein in cancer development. AIM OF THE STUDY: To analyze levels of tissue expression of Srx, Nrf2, and PROX1 in gastric cancer and adjacent non-neoplastic gastric mucosa to clarify the relationship between their expression levels, clinical, pathological parameters and patients' outcome. The results might lead to discovering novel targeted therapies to gastric cancers. MATERIAL AND METHODS: We included 70 paraffin-embedded samples: 50 specimens from gastric carcinomas and 20 specimens from adjacent non-neoplastic gastric mucosa. All samples are stained with Srx, Nrf2, and PROX1 using immunohistochemistry, correlated their expression with clinicopathological and prognostic parameters of patients. RESULTS: High levels of Srx and Nrf2 expression were positively associated with higher cancer grade (p = 0.006, 0.031 respectively), advanced stage (p < 0.001, 0.02 respectively), higher incidence of distant metastases (p = 0.029, 0.03 respectively) and dismal outcome (p < 0.001). High levels of PROX1 expression were associated with lower cancer grade (p = 0.005), absence of lymph nodes metastases (p = 0.023), early stage (p = 0.003), absence of relapse (p = 0.004), and favorable outcome (p < 0.001). CONCLUSIONS: Srx and Nrf2 expression increase gastric cancer invasiveness, suggesting their utility as poor prognostic markers, but PROX1 serves as a favorable prognostic marker of gastric cancer patients.

Does The Type of Shoulder Brace Affect Postoperative Pain and Clinical Outcome After Arthroscopic Rotator Cuff Repair?

PURPOSE: To compare postoperative pain and clinical outcome after arthroscopic rotator cuff repair in patients immobilized with an abduction brace versus patients placed in an antirotation brace. METHODS: One hundred twenty patients (72 women and 48 men) with symptomatic degenerative complete tear of the supraspinatus or infraspinatus tendons were included in the study. Exclusion criteria were history of trauma/traumatic tears, concomitant shoulder pathology, psychological illnesses, and previous shoulder surgery. The Constant-Murley score (CMS) was obtained before surgery and at 3 months, 6 months, and 1 year after surgery. The visual analogue scale (VAS) was done on the day of surgery and at 1 week, 3 weeks, 6 weeks, and 3 months after surgery. Postoperative isokinetic muscle strength evaluation was done for the shoulder external rotator at 1 year. RESULTS: Mean age was 50.4 years for the abduction brace group (ABG) and 50.8 years for the open pouch arm sling group (PASG). The mean level of the VAS score ranged from 75.6 for the ABG and 74.9 for the PASG on the day of the operation to 17.7 and 18.5 at 3 months after surgery. In both groups, the repeated measure analysis of variance showed that there were highly significant changes (P < .001) in the VAS from the day of operation to 3 months after surgery. A significant improvement was detected in both groups in the mean level of the CMS, from 40.9 for the ABG and 41.2 for the PASG before surgery to 84.7 and 84.5 at 1 year after the operation. There was no statistically significant difference between the 2 groups regarding the isokinetic muscle strength, VAS, or the CMS. CONCLUSIONS: Our study did not find a significant difference between abduction brace and antirotation sling in patient-oriented outcome measures or postoperative pain after rotator cuff repair. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Open versus modified arthroscopic treatment of acute acromioclavicular dislocation using a single tight rope: randomized comparative study of clinical outcome and cost-effectiveness.

PURPOSE: The purpose of this study was to compare clinical outcome and cost-effectiveness between arthroscopic and open repair using TightRope in acromioclavicular joint dislocation III and IV. PATIENTS AND METHODS: Fifty-two patients with acute acromioclavicular joint dislocation type III and IV were included. Patients were randomly allocated to either of 2 groups: Arthroscopic Repair Group (ARG) and Open Repair Group (ORG). Constant-Murley Score (CMS), visual analog scale (VAS) score, and coracoclavicular (CC) distance were measured preoperatively and 3 months, 6 months, 1 year, and 2 years postoperatively. RESULTS: CMS increased from 40.68 for the ARG and 40.70 for the ORG preoperatively to 84.18 and 84.45 after 2 years from operation. VAS score decreased from 60.59 for the ARG and 64.50 for the ORG 1 day after surgery to 18.04 and 17.87 respectively after 6 months. CC distance decreased from 29.27 mm in the ARG and 28.16 mm in the ORG preoperatively to 9.86 mm in the ARG and 10.54 mm in the ORG on postoperative day 1. Rewidening of the CC distance occurred after 6 months (13.27 mm for the ARG and 13.62 mm for the ORG) and 1 year postoperatively (15.77 for the ARG and 15.41 for the ORG) but remained stable at final follow-up. There was a significant difference in surgical time (80.00 minutes in the ARG compared to 52.79 minutes in the ORG) and cost of consumables (US$1729.95 in the ARG compared to US$851.87 in the ORG). CONCLUSION: Open and arthroscopic repair of acute acromioclavicular joint dislocation yielded good clinical results, yet the arthroscopic technique is more expensive and has a longer surgical time.

Template-Free Synthesis of Highly b-Oriented MFI-Type Zeolite Thin Films by Seeded Secondary Growth.

Highly b-oriented, closely packed, MFI zeolite films are prepared on seeded stainless-steel plates using organic template-free, secondary growth solutions, containing aluminum sulfate as a crystallization agent. The number of a-oriented twin crystals is significantly reduced, and even eliminated, simply by restricting the pH value of the secondary growth solution to the narrow range of 11.1-11.3. Values of pH can be adjusted through the controlled addition of (NH4 )2 SO4 or H2 SO4 to secondary growth solutions of the composition (1 SiO2 :0.57 NaOH:137.5 H2 O:0.0050 (Al2 (SO4 )3 ⋅18 H2 O)) or by simply decreasing the molar composition of NaOH with no extra additives.

No-Drain Single Incision Liposuction Pull-Through Technique for Gynecomastia.

BACKGROUND: Several different methods have been proposed for treatment of gynecomastia, depending on the amount of breast enlargement and skin redundancy. The liposuction pull-through technique has been proposed as an efficacious treatment for many gynecomastia cases. This work aims to study the outcome of this technique when applied as an outpatient procedure, without the use of drains and through a single incision. METHODS: Fifty-two patients with bilateral gynecomastia without significant skin excess were included in this study. The liposuction pull-through technique was performed through a single incision just above the inframammary fold and without the use of drains. Patients were followed up for 6 months. RESULTS: The proposed technique was able to treat the gynecomastia in all patients, with a revision rate of 1.9% to remove residual glandular tissues. There were no seromas, hematomas, nipple distortion, permanent affection of nipple sensation or wound healing problems. CONCLUSION: The liposuction pull-through technique is an effective treatment for gynecomastia without significant skin redundancy. It combines the benefits of the direct excision of glandular tissues, with the minimally invasive nature of liposuction. Performing the procedure through a single incision without the use of drains and without general anesthesia is a safe alternative. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

Responses to second-line tyrosine kinase inhibitors are durable: an intention-to-treat analysis in chronic myeloid leukemia patients.

Second-generation tyrosine kinase inhibitors (2G-TKIs) are effective at inducing complete cytogenetic responses (CCyRs) in approximately half of chronic myeloid leukemia patients treated while still in the chronic phase and after failing imatinib. It is less clear whether these responses are durable. In the present study, we report the clinical outcome of 119 patients who received a 2G-TKI as second-line treatment while still in the chronic phase. In an intention-to-treat analysis, the 4-year probabilities of overall and event-free survival were 81.9% and 35.3%, respectively. Sixty-two patients discontinued the initial 2G-TKI because of resistance or intolerance. To further explore the durability of cytogenetic responses, irrespective of the need for a third-line TKI, we used the concept of "current CCyR-survival" (c-CCyRS). The c-CCyRS at 4 years was 54.4%. After introduction of a 2G-TKI, 77 patients had a 3-month BCR-ABL1/ABL1 transcript ratio of ≤ 10% and had significantly superior overall survival (91.3% vs 72.1%, P = .02), event-free survival (49.3% vs 13.0%, P < .001), and c-CCyRS (67.2% vs 11.2%, P = .0001) compared with the 33 patients with ratios > 10%. The 3-month molecular response was the only independent predictor for overall survival. Using an intention-to-treat analysis, we have shown that the responses to second-line therapies are durable. Patients destined to fare poorly can be identified early during therapy.

Correction and removal of expression of concern: Palladium supported on mixed-metal-organic framework (Co-Mn-MOF-74) for efficient catalytic oxidation of CO.

[This corrects the article DOI: 10.1039/D0RA09970H.].

Expression of concern: Palladium supported on mixed-metal-organic framework (Co-Mn-MOF-74) for efficient catalytic oxidation of CO.

Expression of Concern for 'Palladium supported on mixed-metal-organic framework (Co-Mn-MOF-74) for efficient catalytic oxidation of CO' by Reda S. Salama et al., RSC Adv., 2021, 11, 4318-4326, https://doi.org/10.1039/D0RA09970H.

A comparative study of α-Ni(OH)2 and Ni nanoparticle supported ZIF-8@reduced graphene oxide-derived nitrogen doped carbon for electrocatalytic ethanol oxidation.

Ethanol electrooxidation is an important reaction for fuel cells, however, the major obstacle to ethanol electrocatalysis is the splitting of the carbon-carbon bond to CO2 at lower overpotentials. Herein, a ZIF-8@graphene oxide-derived highly porous nitrogen-doped carbonaceous platform containing zinc oxide was attained for supporting a non-precious Ni-based catalyst. The support was doped with the disordered α-phase Ni(OH)2 NPs and Ni NPs that are converted to Ni(OH)2 through potential cycling in alkaline media. The Ni-based catalysts exhibit high electroactivity owing to the formation of the NiOOH species which has more unpaired d electrons that can bond with the adsorbed species. From CV curves, the EOR onset potential of the α-Ni(OH)2/ZNC@rGO electrode is strongly shifted to negative potential (Eonset = 0.34 V) with a high current density of 8.3 mA cm-2 relative to Ni/ZNC@rGO. The high catalytic activity is related to the large interlayer spacing of α-Ni(OH)2 which facilitates the ion-solvent intercalation. Besides, the porous structure of the NC and the high conductivity of rGO facilitate the kinetic transport of the reactants and electrons. Finally, the catalyst displays a high stability of 92% after 900 cycles relative to the Ni/ZNC@rGO and commercial Pt/C catalysts. Hence, the fabricated α-Ni(OH)2/ZNC@rGO catalyst could be regarded as a potential catalyst for direct EOR in fuel cells.

Mycotic Aortic Aneurysm Secondary to Salmonella enterica Infection: A Case Report and Treatment Approach.

Mycotic (infected) aortic aneurysm is a severe clinical condition with high morbidity and mortality. Salmonella spp. is a Gram-negative, rod-shaped bacteria that is typically limited to the gastrointestinal tract and resolves spontaneously but can progress to invasive infections such as bacteremia. Serious complications may arise, particularly in debilitated, elderly, and neonatal patients. We describe the case of a 74-year-old female with a history of diabetes and hypertension who presented with shortness of breath, fever, chills, abdominal pain, vomiting, and diarrhea. The patient's blood culture tested positive for Salmonella enterica, and she was given ceftriaxone based on the results, but he remained symptomatic. A computed tomography scan of the chest with contrast revealed a mycotic aneurysm of the thoracic aorta. The patient was urgently transferred to a higher level of care and underwent emergency thoracic endovascular aortic repair with stenting and intravenous antibiotics. The presence of an infected aneurysm and associated abscess formation in such high-risk patients makes the endovascular approach more suitable than other options such as open surgery, aneurysmal excision and ligation without arterial reconstruction, excision with immediate reconstruction, and excision with interval reconstruction.

Selective Reduction of Multivariate Metal-Organic Frameworks for Advanced Electrocatalytic Cathodes in High Areal Capacity and Long-Life Lithium-Sulfur Batteries.

Lithium-sulfur batteries hold great promise as next-generation high-energy-density batteries. However, their performance has been limited by the low cycling stability and sulfur utilization. Herein, we demonstrate that a selective reduction of the multivariate metal-organic framework, MTV-MOF-74 (Co, Ni, Fe), transforms the framework into a porous carbon decorated with bimetallic CoNi alloy and Fe3O4 nanoparticles capable of entrapping soluble lithium polysulfides while synergistically facilitating their rapid conversion into Li2S. Electrochemical studies on coin cells containing 89 wt % sulfur loading revealed a reversible capacity of 1439.8 mA h g-1 at 0.05 C and prolonged cycling stability for 1000 cycles at 1 C/1060.2 mA h g-1 with a decay rate of 0.018% per cycle. At a high areal sulfur loading of 6.9 mg cm-2 and lean electrolyte/sulfur ratio (4.5 µL:1.0 mg), the battery based on the 89S@CoNiFe3O4/PC cathode provides a high areal capacity of 6.7 mA h cm-2. The battery exhibits an outstanding power density of 849 W kg-1 at 5 C and delivers a specific energy of 216 W h kg-1 at 2 C, corresponding to a specific power of 433 W kg-1. Density functional theory shows that the observed results are due to the strong interaction between the CoNi alloy and Fe3O4, facilitated by charge transfer between the polysulfides and the substrate.

Poor adherence is the main reason for loss of CCyR and imatinib failure for chronic myeloid leukemia patients on long-term therapy.

We studied the relation between adherence to imatinib measured with microelectronic monitoring systems and the probabilities of losing a complete cytogenetic response (CCyR) and of imatinib failure in 87 CCyR chronic myeloid leukemia patients receiving long-term therapy. We included in our analysis the most relevant prognostic factors described to date. On multivariate analysis, the adherence rate and having failed to achieve a major molecular response were the only independent predictors for loss of CCyR and discontinuation of imatinib therapy. The 23 patients with an adherence rate less than or equal to 85% had a higher probability of losing their CCyR at 2 years (26.8% vs 1.5%, P = .0002) and a lower probability of remaining on imatinib (64.5% vs 90.6%, P = .006) than the 64 patients with an adherence rate more than 85%. In summary, we have shown that poor adherence is the principal factor contributing to the loss of cytogenetic responses and treatment failure in patients on long-term therapy.

The BCR-ABLT315I mutation compromises survival in chronic phase chronic myelogenous leukemia patients resistant to tyrosine kinase inhibitors, in a matched pair analysis.

The BCR-ABL T315I mutation confers resistance to currently licensed tyrosine kinase inhibitors in chronic myelogenous leukemia. However, the impact of this mutation on survival in early stages of disease, in chronic phase, has never been detailed. Using matched pair analysis, a cohort of 64 patients with chronic phase chronic myelogenous leukemia harboring a T315I mutation and resistant to imatinib mesylate was compared to a similar cohort of 53 chronic phase patients resistant to imatinib, but with no detectable T315I mutation, in the pre-ponatinib era. These patients were matched according to age at diagnosis, interval between disease diagnosis and start of imatinib treatment, and duration of imatinib therapy. Kaplan-Meier survival analyses demonstrated the significant negative impact of the presence of the T315I mutation on overall survival (since imatinib-resistance: 48.4 months for T315I(+) patients versus not reached for T315I(-) ones; P=0.006) and failure-free survival (since imatinib-resistance: 34.7 months for T315I(+) patients versus not reached for T315I(-) patients; P=0.003). In addition, Cox proportional hazard models adjusted on overall survival demonstrated the negative influence of the T315I mutation (P=0.02, HR=2.54). These results confirm early assumptions concerning the poor prognosis of chronic phase chronic myelogenous leukemia patients with the T315I mutation who are not eligible for allogeneic transplantation, and demonstrate the need for more therapeutic options.

Stable polyethylene glycol/biochar composite as a cost-effective photothermal absorber for 24 hours of steam and electricity cogeneration.

Seawater desalination powered by solar energy is the most environmentally and economical solution in responding to the global water and energy crisis. However, solar desalination has been negatively impacted by intermittent sun radiation that alternates between day and night. In this study, sugarcane bagasse (SCB) was recycled via the pyrolysis process to biochar as a cost-effective solar absorber. Besides, polyethylene glycol (PEG) as a phase change material was encapsulated in the abundant pore structure of biochar to store the thermal energy for 24 hours of continuous steam generation. The BDB/1.5 PEG evaporator exhibited an evaporation rate of 2.11 kg m-2 h-1 (98.1% efficiency) under 1 sun irradiation. Additionally, the BDB/1.5 PEG evaporator incorporated by the TEC1-12706 module for continuous steam and electricity generation with a power density of 320.41 mW m-2. Moreover, 10 continuous hours of evaporation were applied to the composite demonstrating outstanding stability. The composite exhibited high water purification efficiency through solar desalination due to the abundant functional groups on the biochar surface. Finally, the resulting low-cost and highly efficient PCM-based absorber can be used on a wide scale to produce fresh water and energy.

Construction of thickness-controllable bimetallic sulfides/reduced graphene oxide as a binder-free positive electrode for hybrid supercapacitors.

Devices for electrochemical energy storage with exceptional capacitance and rate performance, outstanding energy density, simple fabrication, long-term stability, and remarkable reversibility have always been in high demand. Herein, a high-performance binder-free electrode (3D NiCuS/rGO) was fabricated as a supercapacitor by a simple electrodeposition process on a Ni foam (NF) surface. The thickness of the deposited materials on the NF surface was adjusted by applying a low cycle number of cyclic voltammetry (5 cycles) which produced a thin layer and thus enabled the easier penetration of electrolytes to promote electron and charge transfer. The NiCuS was anchored by graphene layers producing nicely integrated materials leading to a higher electroconductivity and a larger surface area electrode. The as-fabricated electrode displayed a high specific capacitance (2211.029 F g-1 at 5 mV s-1). The NiCuS/rGO/NF//active carbon device can achieve a stable voltage window of 1.5 V with a highly specific capacitance of 84.3 F g-1 at a current density of 1 A g-1. At a power density of 749 W kg-1, a satisfactory energy density of 26.3 W h kg-1 was achieved, with outstanding coulombic efficiency of 100% and an admirable life span of 96.2% after 10 000 GCD cycles suggesting the significant potential of the as-prepared materials for practical supercapacitors.

Cesium salt of tungstophosphoric acid/mesoporous (zirconia-silica) composite for highly efficient synthesis of 7-hydroxy-4-methyl coumarin and removal of methylene blue.

The removal of harmful organic dyes from aqueous solutions has drawn the attention of scientists because of the substantial threat they pose to society's worldwide health. Hence, it is crucial to design an adsorbent that is both very effective in removing dyes and has the benefit of being inexpensive. In the present work, Cs salts of tungstophosphoric acid (CPW) supported mesoporous Zr-mSiO2 (mZS) with varying extents of Cs ions have been prepared by a two-step impregnation technique. Accordingly, a lowering in the surface acidity modes was observed after Cs exchanged protons of H3W12O40 and formed salts immobilized on the mZS support. After exchanging the protons with Cs ions, the characterization results revealed that the primary Keggin structure was unaltered. Moreover, the Cs exchanged catalysts had higher surface area than the parent H3W12O40/mZS, suggesting that Cs reacts with H3W12O40 molecules to create new primary particles with smaller sizes possessing inter-crystallite centers with a higher dispersion degree. With an increase in Cs content and thus a decrease in the acid strength and surface acid density, the methylene blue (MB) monolayer adsorption capacities on CPW/mZS catalysts were increased and reached an uptake capacity of 359.9 mg g-1 for Cs3PW12O40/mZS (3.0CPW/mZS). The catalytic formation of 7-hydroxy-4-methyl coumarin was also studied at optimum conditions and it is found that the catalytic activity is influenced by the amount of exchangeable Cs with PW on the mZrS support, which is in turn influenced by the catalyst acidity. The catalyst kept approximately the initial catalytic activity even after the fifth cycle.