Contemporary advances in photocatalytic CO2 reduction using single-atom catalysts supported on carbon-based materials.

The persistent issue of CO2 emissions and their subsequent impact on the Earth's atmosphere can be effectively addressed through the utilization of efficient photocatalysts. Employing a sustainable carbon cycle via photocatalysis presents a promising technology for simultaneously managing the greenhouse effect and the energy dilemma. However, the efficiency of energy conversion encounters limitations due to inadequate carrier utilization and a deficiency of reactive sites. Single-atom catalysts (SACs) have demonstrated exceptional performance in efficiently addressing the aforementioned challenges. This review article commences with an overview of SAC types, structures, fundamentals, synthesis strategies, and characterizations, providing a logical foundation for the design and properties of SACs based on the correlation between their structure and efficiency. Additionally, we delve into the general mechanism and the role of SACs in photocatalytic CO2 reduction. Furthermore, we furnish a comprehensive survey of the latest advancements in SACs concerning their capacity to enhance efficiency, long-term stability, and selectivity in CO2 reduction. Carbon-structured support materials such as covalent organic frameworks (COFs), graphitic carbon nitride (g-C3N4), metal-organic frameworks (MOFs), covalent triazine frameworks (CTFs), and graphene-based photocatalysts have garnered significant attention due to their substantial surface area, superior conductivity, and chemical stability. These carbon-based materials are frequently chosen as support matrices for anchoring single metal atoms, thereby enhancing catalytic activity and selectivity. The motivation behind this review article lies in evaluating recent developments in photocatalytic CO2 reduction employing SACs supported on carbon substrates. In conclusion, we highlight critical issues associated with SACs, potential prospects in photocatalytic CO2 reduction, and existing challenges. This review article is dedicated to providing a comprehensive and organized compilation of recent research findings on carbon support materials for SACs in photocatalytic CO2 reduction, with a specific focus on materials that are environmentally friendly, readily accessible, cost-effective, and exceptionally efficient. This work offers a critical assessment and serves as a systematic reference for the development of SACs supported on MOFs, COFs, g-C3N4, graphene, and CTFs support materials to enhance photocatalytic CO2 conversion.

First-principle calculations to investigate structural, electronic, mechanical, optical, and thermodynamic features of promising (La, In)-doped AlSb for optoelectronic applications.

CONTEXT: A remarkable change in lattice parameters and bulk modulus is achieved by the suitable addition of Al (Al1-x Lax Sb) and In (Al1-x Inx Sb) atoms in the AlSb compound. Electronic responses like band structure, the total partial density of states, and the elemental density of states are thoroughly investigated. The computed values indicate that the binary compound AlSb is an indirect band gap and an optically inactive response. After increasing the doping concentrations (0.25, 0.5, 0.75) of La and In in AlSb, the band gap changes from indirect to direct nature. Hence, Al1-0.75 La0.25 Sb, Al1-0.50 La0.50 Sb, Al1-0.75 In0.25Sb, and Al1-0.50 In0.50Sb become optically active. The illustrious roles of Al-3p and In-4d states on the band gap and nonlinear responses of these compounds are extensively explored by the comparison between the computed results of ultra-soft and norm converging pseudopotentials. The excess specific heat (CV), enthalpy of mixing (Hm), and phonon dispersion curves resulting from the concentrations "x" are estimated in order to investigate the thermodynamic stability responses of the pristine and doped AlSb. The obtained CV and thermal coefficient statistics for Al1-x Lax Sb and Al1-x Inx Sb may be useful for a good mapping of experimental results and examining these compounds' enharmonic responses. There is a valuable change in optical characteristics like dielectric functional, absorption, conductivity, and refractive index due to the addition of (La, In) impurities in AlSb. It is further observed that Al1-0.75 La0.25 Sb, Al1-0.50 La0.50 Sb, Al1-0.75 In0.25Sb, and Al1-0.50 In0.50Sb are significantly mechanically stable compared to pristine AlSb. The above results suggest that Al1-x Lax Sb and Al1-x Inx Sb are high-performance optical materials and can be promising potential candidates for optoelectronic applications. METHODS: The structural, electronic, mechanical, vibrational, and optical responses of the pure and doped Al1-0.75 La0.25 Sb, Al1-0.50 La0.50 Sb, Al1-0.75 In0.25Sb, and Al1-0.50 In0.50Sb are investigated, using Heydscuseria-Ernzerhof screened hybrid functional (HSEO6) and generalized gradient approximation (GGA) with norm-converging and ultra-soft pseudopotential techniques in the density functional theory.

Synergistic catalytic enhancement of metal-organic framework derived nanoarchitectures decorated on graphene as a high-efficiency bifunctional electrocatalyst for methanol oxidation and oxygen reduction.

Designing highly efficient, long-lasting, and cost-effective cathodic and anodic functional materials as a bifunctional electrocatalyst is essential for overcoming the bottleneck in fuel cell development. Herein, a novel two-step synthesis strategy is developed to synthesize metal-organic framework (MOF) derived nitrogen-doped carbon (NC) with improved spatial isolation and a higher loading amount of cobalt (Co) and nickel carbide (Ni3C) nanocrystal decorated on graphene (denoted as Co@NC-Ni3C/G). Benefiting from multiple active sites of high N-doping level, uniform dispersion of Co and Ni3C nanocrystals, and a large active area of graphene, the Co@NC-Ni3C/G hybrids exhibit excellent methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR) efficiency in an alkaline environment. For MOR, the optimized Co@NC-Ni3C/G-350 catalyst achieved a current density of 44.8 mA cm-2 at an applied potential of 1.47 V (V vs. RHE), which is significantly higher than Co@NC-Ni3C (42.07 mA cm-2) and Co@NC (24.1 mA cm-2) in 0.5 M methanol + 1.0 M KOH solutions. In addition, during the CO retention test, the Co@NC-Ni3C/G-350 catalyst exhibits excellent CO tolerance capacity. Excitingly, the as-prepared Co@NC-Ni3C/G-350 hybrid exhibits significantly improved ORR catalytic efficiency in terms of positive onset and half-wave potential (Eonset = 0.90 V, E1/2 = 0.830 V vs. RHE), small Tafel slope (34 mV dec-1) and excellent durability (only reduced 0.016 V after 5000 s test). This work provides new insights into MOF-derived functional nanomaterials for anode and cathode co-catalysts for methanol fuel cells.

Trigonella foenum-graecum Seeds Oil Attenuated Inflammation and Angiogenesis in vivo through Down-Regulation of TNF-α.

INTRODUCTION: Inflammation is a vital reaction of the natural immune system that protects against encroaching agents. However, uncontrolled inflammation can lead to complications. Trigonella foenumgraecum is traditionally used as an anti-inflammatory herb. OBJECTIVES: The current study was conducted to explore the antioxidant, anti-inflammatory, and antiangiogenic potentials of Trigonella foenum-graecum seeds oil. METHODS: Oil was extracted from seeds of Trigonella foenum-graecum by cold press method and labelled as TgSO. Phytochemical (GC-MS, Folin-Ciocalteu method) and metal analyses were conducted to evaluate the metalo-chemical profile of TgSO. In vitro antioxidant assays (2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis-3- ethylbenzothiazoline-6-sulfonic acid and ferric reducing antioxidant power) were performed to assess its antioxidant potential. In vitro antimicrobial activity was evaluated using agar disc diffusion method and the safety profile of TgSO was assessed in acute toxicological studies following OECD 425 guidelines. In vivo antiinflammatory activities of TgSO were assessed in carrageenan, serotonin, histamine, formalin, and cotton pelletinduced oedema models. Serum TNF-α, Superoxide Dismutase (SOD) and, Catalases (CAT) levels were assessed by ELISA kits. In vivo antiangiogenic activity of TgSO was screened in chick Chorioallantoic Membrane (CAM) assay. Histopathological studies using excised paws were conducted to observe the effects of TgSO treatment at the tissue level. In silico docking studies were conducted to screen the binding potentials of identified compounds with TNF-α. RESULTS: Extraction by cold press method yielded 16% of TgSO. Phytochemical analysis of TgSO through GCMS showed the presence of eugenol, dihydrocoumairn, heptadecanoic acid, tri- and tetradecanoic acid, and hexadecanoic acid, respectively. Total phenolic contents of TgSO were found to be 0.30±0.01mg/g gallic acid equivalent in Folin-Ciocalteu method. Metal analysis indicated the presence of different metals in TgSO. Findings of antioxidant models showed the moderate antioxidant potential of TgSO. Findings of antimicrobial assays showed that TgSO was active against bacterial (S. aureus, S. epidermidis) and fungal (C. albicans, and A. niger) strains. In vivo toxicity study data showed that TgSO was safe up to the dose of 5000 mg/kg. Data of oedema models showed a significant (p<0.05) reduction in oedema development in TgSO treated animals in both acute and chronic models. Histopathological evaluations of paws showed minimum tissue infiltration with inflammatory cells in TgSO-treated animals. Treatment with TgSO also significantly (p<0.05) down-regulated TNF-α in serum while levels of SOD and CAT were up-regulated. Findings of the CAM assay revealed the antiangiogenic activity of TgSO. Findings of in silico docking studies showed that identified phytoconstituents can bind with culprit cytokine (TNF-α). CONCLUSION: Data obtained from the current study conclude that TgSO has antioxidant, anti-inflammatory, and antiangiogenic effects that validate its traditional uses. Synergistic actions of different phytoconstituents are proposed to be responsible for the observed effects.

Correction to: Evaluation of in vivo anti-inflammatory and anti-angiogenic attributes of methanolic extract of Launaea spinosa.

Unfortunately, a section under the heading "Materials and Method" has been published with errors.

Methanolic extract of Ephedra ciliata promotes wound healing and arrests inflammatory cascade in vivo through downregulation of TNF-α.

Chronic wounds may lead to the development of various pathological conditions such as diabetic foot ulcers and pressure sores. The current study evaluated wound healing and anti-inflammatory potentials of methanolic extract of Ephedra ciliata using series of in vivo models. Methanolic extract of Ephedra ciliata was prepared by maceration (Ec.Me). Qualitative and quantitative (HPLC) phytochemical and metal analyses were conducted to explore the chemical and metal profiles of Ec.Me. Safety profile (behavioural) and, antimicrobial, antioxidant, wound healing, anti-inflammatory and anti-angiogenic potentials of Ec.Me were evaluated using well-established in vitro and in vivo models. ELISA assay was performed to estimate the effects of Ec.Me treatment on serum levels of TNF-α. HPLC analysis identified quercetin as one of the major compounds in Ec.Me. Safety study data showed that Ec.Me was safe up to the dose of 2000 mg/kg. Antimicrobial assay data showed that Ec.Me was active against bacterial (Staphylococcus aureus) as well as fungal (Candida albicans and Aspergillus niger) strains. Ec.Me showed modertate antioxidant potential in in vitro and in vivo models. Data of excision and burn wound healing models showed that Ec.Me, promoted wound closure in a dose and time-dependent manner. Treatment with 20% Ec.Me cream and heparin showed almost the same effects with no statistical differences (p > 0.05). Ec.Me also showed time-dependent anti-inflammatory activities in both acute and chronic models. In carrageenan model, treatment with 200 mg/kg of Ec.Me showed comparable anti-inflammatory effects (p > 0.05) with quercetin and indomethacin throughout the study. In cotton pellet granuloma model treatment with 200 mg/kg of Ec.Me and indomethacin inhibited granuloma formation significantly better (p < 0.05) as compared with the rest of the treatment groups. Histopathological examination of skin samples showed marked improvement in architecture with minimal infiltration of inflammatory cells. Data of in vivo angiogenesis assay showed marked improvement in vessels length, density, branching points, total segments and total nets after treatment with Ec.Me, indicating no toxic effects towards vasculature development. Significant (p < 0.05) downregulation of TNF-α was observed in serum samples of animals treated with Ec.Me. Based on data of the current study, it is concluded that quercetin-rich extract of Ephedra ciliata has wound healing and anti-inflammatory potentials via downregulation of TNF-α. Moreover, it is suggested that the antimicrobial activity of Ec.Me prevented microbial invasion, thus promoted natural wound healing mechanisms as well.

Evaluation of in vivo anti-inflammatory and anti-angiogenic attributes of methanolic extract of Launaea spinosa.

Launaea spinosa is used as an anti-inflammatory agent traditionally. This study was conducted to evaluate anti-inflammatory and anti-angiogenic activities of methanol extract of Launaea spinosa. Extraction was performed by maceration and the resultant green coloured extract was labelled as Ls.Me. Solubility analysis showed that Ls.Me was miscible with distilled water, normal saline, ethanol and methanol. Metal analysis following acid digestion method exhibited the presence of copper, magnesium, manganese, iron, zinc and calcium. Phytochemical analysis confirmed the presence of different classes of secondary metabolites in Ls.Me. HPLC analysis showed the presence of quercetin, gallic acid, caffeic acid, benzoic acid and sinapic acid in Ls.Me. Data of in vitro antioxidant assays showed moderate antioxidant potential of Ls.Me which was also confirmed by data of in vivo enzymes (SOD, CAT, and TSP) assays. Antimicrobial assays data showed that Ls.Me was active against S.aureus and S.epidermidis (bacterial) as well as C.albicans and A.niger (fungal) strains. Data of acute physio-pathological studies showed no abnormalities in Albino rats up to the dose of 2000 mg/kg of Ls.Me. Acute and chronic inflammatory models were used to evaluate anti-inflammatory effects of Ls.Me. Data of acute studies showed that Ls.Me has the potential to arrest inflammation produced by different mediators in a dose-dependent manner. 200 mg/kg of Ls.Me was found to produce significantly (p < 0.05) better anti-inflammatory effects than 100 mg/kg of Ls.Me. Ls.Me also significantly (p < 0.05) inhibited ear edema induced by xylene. Ls.Me showed profound anti-inflammatory responses in paw edema induced by formalin and also inhibited granuloma development in cotton pellet-induced granuloma model. Histopathological and biochemical investigations showed marked reduction in the number of inflammatory cells. TNF-α and IL-6 ELSIA kits were used to study effects of Ls.Me treatment on serum levels of TNF-α and IL-6. Data obtained showed significant (p < 0.05) reduction in TNF-α and IL-6 levels in serum of animals treated with Ls.Me. Data of in vivo angiogenesis assay showed that 200 µg/ml of Ls.Me significantly halted vasculature development indicating its potent anti-angiogenic potential. On the basis of findings of the current study, it is concluded that multiple phytochemicals present in Ls.Me act synergistically to produce anti-inflammatory and anti-angiogenic effects. Further studies are required to standardize the plant extract and explore its safety profile.

Prevalence, Risk Factors, Treatment, and Overall Impact of BK Viremia on Kidney Transplantation.

BK viremia (BKV) is a recognized and potentially serious problem in renal transplantation. The risk factors and the impact of BKV on renal allograft and patient survival are controversial. This study reports an 8-year, single-center experience on the prevalence, risk factors, and outcomes of BKV in kidney transplant recipients. This is a retrospective analysis of all patients who received a kidney transplant at the University of Kentucky and had BK viral titers available from 2009 to 2017. BKV was defined by a polymerase chain reaction viral load of ≥ 10,000 copies per mL. Demographic, clinical, and laboratory data generated during routine outpatient follow up and inpatients records were collected. Independent risk factors for BKV were determined using uni- and multivariate analysis. Graft and patient survival was compared using Kaplan-Meier analysis, and the severity of polyomavirus nephropathy on biopsy was scored using the Banff 2017 classification. We identified 122 BK positive (19%) and 527 BK negative (81%) patients. BKV developed after a median of 115 days (range, 80-249 days) following kidney transplantation. The 1-, 5-, and 10-year graft survival was 97%, 75%, and 33% in the BKV group and 96%, 85%, and 71% in the BK negative group, respectively. Likewise, the 1-, 5-, and 10-year patient survival was 98%, 84%, and 52% in the BKV group and 98%, 92%, and 84% in the BK negative group. Male sex, age at transplantation, maintenance steroids, and alemtuzumab induction were associated with developing BKV in the multivariate analysis. We concluded that BKV is not uncommon after renal transplantation. The determinants for BKV are male sex, older transplant recipients, and maintenance steroids. BKV adversely affected graft and patient survival. A unified approach for BKV and polyomavirus nephropathy treatment is needed.

Impact of Recent Clinical Trials on Nephrology Practice: Are We in a Stagnant Era?

BACKGROUND: Although renal replacement therapy prevents death from uremia, survival among patients with acute and chronic kidney diseases (CKD) remains an imperative concern. The expected life span of US dialysis patients 60-64 years of age is approximately 4.5 years; this is similar to that of patients with lung cancer. Despite substantial progress in many medical specialties over the past decades (e.g., notable reductions in myocardial infarction, stroke, and mortality rates in the general population), survival among dialysis patients has not improved significantly over the same period. A few decades ago, HIV infection and AIDS were pretty much a death sentence. Because of progress in HIV treatment, now it can be controlled with a daily pill, and ongoing research is pushing treatment even further and controls the virus with longer-acting treatment. A cure is no longer impossible for HIV and other viral infections such as hepatitis B and C and many malignancies, but so far there is no cure for CKD. SUMMARY: Billions of dollars have been spent on kidney disease research in the past decades, with no tangible progress in clinical practice. The challenges of improving the quantity and quality of trials in nephrology are enormous. The number of randomized controlled trials (RCTs) published in nephrology is lower than that in other medical subspecialties, and most of the big RCTs in nephrology yield negative results. Nephrology studies evaluating hard clinical endpoints or surrogate endpoints are scarce. KEY MESSAGE: Herein we discuss the slow progress in nephrology research that has impacted clinical practice over the last couple of decades and highlight the major obstacles, challenges, and potential solutions.

Impact of human leukocyte antigen and calculated panel reactive antibody on BK viremia in kidney transplant recipients: A single-center experience and literature review.

BACKGROUND: The aim of this retrospective analysis was to investigate the effect of human leukocyte antigen (HLA) and calculated panel reactive antibody (cPRA) on BK virus activation as evidenced by BK viremia (BKV). PATIENTS AND METHODS: At our institution, 649 kidney transplant patients were screened for BKV from 2009 to 2017. Patients were considered to have BKV if they had >10 000 copies/mL of BK DNA in their blood. Donor and recipient HLA and cPRA, demographic, clinical and laboratory data, as well as immunosuppressive medications were collected. RESULTS: We identified 122 BK positive and 527 BK negative patients. Only 25% of the patients had cPRA of 20% or more, and 64% had more than three HLA-A, -B, and -DR mismatches. In both univariate and multivariate analyses, male gender, age, and maintenance of steroid therapy significantly increased the risk of BKV (P = 0.005, 0.005 and <0.001, respectively). The degree of cPRA and the individual HLA allele and HLA allele matching did not significantly affect BKV. CONCLUSION: Neither the degree of HLA mismatching nor cPRA appears to affect BKV. Moreover, no specific HLA allele, HLA allele matching, or cPRA were associated with BKV.

PTH assays in dialysis patients: Practical considerations.

Parathyroid hormone (PTH) 1-84 is the main biologically active hormone produced by the parathyroid cells. Circulating PTH molecules include the whole PTH 1-84 along with amino (N) and carboxyl (C) terminal fragments. While PTH is the best available noninvasive biomarker to assess bone turnover in dialysis patients, the biological roles of individual circulating PTH fragments are still not completely known. The understanding that there is an enormous variation in the target specificity of currently available PTH assays for different circulating forms of PTH has led to the evolution of assays from first to second then third generation. With a reduction in kidney function, there is a preferential increase in circulating C fragments and non-PTH 1-84 forms, resulting in a decrease in the ratio of PTH 1-84/non-PTH 1-84. However, there are also substantial differences in between-assay measurements, with several fold variations in results. Targets based on multiples of the upper limit of normal (ULN) should be used rather than PTH ranges using absolute iPTH values. To date, the second-generation PTH remains the most widely used assay. Current guidelines recommend following iPTH trends rather than absolute values. Herein, we highlight problems and challenges in PTH assays/measurements and their interpretations in dialysis patients.

Cardiac Arrest Due to Air Embolism: Complicating Image-guided Lung Biopsy.

Cardiac arrest due to air embolism is an infrequent complication. Air embolism can be associated with procedures like endoscopic retrograde cholangiopancreatography, endoscopic variceal ligation, operative hysteroscopy, laparoscopic surgery, pacemaker placement, cardiac ablation, fiberoptic bronchoscopy, and decompression sickness. In rare cases, air embolus can be a catastrophic complication of computed tomography (CT) guided lung biopsy, which can lead to cardiac arrest. We present a case of a 67-year-old male chronic smoker with a left lower lobe pulmonary nodule who had a cardiac arrest due to air embolism as a consequence of CT guided biopsy of the pulmonary nodule found on a CT scan of the chest. He was successfully resuscitated and intubated for mechanical ventilation. He was managed conservatively and discharged home in a stable condition.