Role of the Solvent and Intramolecular Hydrogen Bonds in the Antioxidative Mechanism of Prenylisoflavone from Leaves of Vatairea guianensis.

This work discusses the electron structure, antioxidative properties, and solvent contribution of two new antioxidant molecules discovered, named S10 and S11, extracted from a medicinal plant called Vatairea guianensis, found in the Amazon rain-forest. To gain a better understanding, a study using density functional theory coupled with the polarizable-continuum model and the standard 6-311++G(d,p) basis set was conducted. The results indicate that S10 has a higher antioxidant potential than S11, confirming the experimental expectations. In the gas phase, the hydrogen atom transfer route dominates the hydrogen scavenging procedure. However, in the water solvents, the antioxidant mechanism prefers the sequential proton loss electron transfer mechanism. Furthermore, the solvent plays a fundamental role in the antioxidant mechanism. The formation of an intramolecular OH···OCH3 hydrogen bond is crucial for accurately describing the hydrogen scavenging phenomenon, better aligning with the experimental data. The results suggest that the two isoflavones investigated are promising for the pharmacologic and food industries.

For Patients With Acute PJI Treated With Debridement, Antibiotics, and Implant Retention, What Factors Are Associated With Systemic Sepsis and Recurrent or Persistent Infection in Septic Patients?

BACKGROUND: Periprosthetic joint infection (PJI) can lead to a severe systemic inflammatory response and may result in systemic sepsis. However, little is known about how often systemic sepsis may occur in patients with PJI, and whether sepsis is associated with a greater likelihood of persistent or recurrent PJI. QUESTIONS/PURPOSES: (1) Among patients who present with acute or acute hematogenous PJI and who were treated with debridement, antibiotics, and implant retention (DAIR), what proportion have sepsis and what factors are associated with a presentation with sepsis? (2) For patients presenting with sepsis, what factors are associated with persistent or recurrent PJI? METHODS: In all, 320 patients who underwent DAIR for the treatment of acute postoperative or acute hematogenous PJI between January 2000 and December 2019 were included in this study. Exclusion criteria were patients with other known sources of infection, such as pneumonia or urinary tract infections, which could contribute to systemic sepsis (6% [18 of 320]), patients with chronic PJI, and those with less than 6 months of follow-up (21% [66 of 320]). Our final cohort consisted of 236 patients presenting with an acute postoperative or acute hematogenous PJI who underwent an irrigation and debridement procedure. Sepsis was defined by the criteria for systemic inflammatory response syndrome (SIRS) or bacteria-positive blood culture results. Inclusion of patients with positive blood culture by organisms that caused their joint infection was important as all patients presented with fulminant acute infection of a prosthetic joint. Data, including vital signs, surgical variables, and treatment outcomes, were collected retrospectively through a chart review of an electronic medical record system. The statistical analysis comparing patients with sepsis versus patients without sepsis consisted of logistic regression to identify factors associated with sepsis. After confirming its ability to identify patients with a higher association with the development of sepsis through area under the curve models, a nomogram was generated to standardize our results from the regression, which was supported by the area under the curve model, to help readers better identify patients who are more likely to develop sepsis. RESULTS: A total of 44% (103 of 236) of patients had infections that met the criteria for sepsis. After controlling for confounding variables, including congestive heart failure, anemia, serum C-reactive protein (CRP), and the male sex, it was revealed that serum CRP (odds ratio 1.07 [95% confidence interval 1.04 to 1.11]; p < 0.001) and male sex (OR 1.96 [95% CI 1.03 to 3.81]; p = 0.04) were associated with the development of systemic sepsis. For patients presenting with sepsis, persistent or recurrent PJI were associated with an increased CRP level (OR 1.06 [95% CI 1.02 to 1.11]; p = 0.01) and number of prior surgical procedures on the joint (OR 2.30 [95% CI 1.21 to 4.89]; p = 0.02). CONCLUSION: Overall, our findings support that patients with systematic sepsis may benefit from two-stage revision rather than DAIR to decrease the bioburden more effectively, especially in those with methicillin-resistant Staphylococcus aureus and polymicrobial infections. High serum CRP levels and a history of prior surgical procedures on the involved joint should trigger prompt, aggressive surgical treatment if the patient's overall clinical status can tolerate such an intervention. LEVEL OF EVIDENCE: Level III, therapeutic study.

Are Patients With End-Stage Arthritis Willing to Delay Arthroplasty for Payer-Mandated Physical Therapy?

BACKGROUND: Payer coverage policies have recently begun requiring physical therapy (PT) prior to total hip arthroplasty and total knee arthroplasty (TKA). It remains controversial if such a mandate is appropriate for patients with end-stage, symptomatic osteoarthritis. The purpose of this study is to assess if such patients are amenable to delaying surgery for a trial of PT. METHODS: All patients scheduled for elective primary total hip arthroplasty and TKA in a 3-month period by 1 of 7 surgeons at a single institution were contacted and asked to participate in a survey. Participation in PT within the prior 6 months was noted. Patients were asked if they would be willing to delay surgery for a PT trial as a nonsurgical option to improve their symptoms. The primary reason for their answer was also recorded. RESULTS: In total, 200 patients were successfully contacted and agreed to participate. The mean age was 66 years, 47% were male, the mean body mass index was 31 kg/m2, and 66% were scheduled for TKA. In total, 157 patients (79%) stated they had not done PT in the preceding 6 months, and 185 patients (93%) stated they would not want to delay surgery for mandatory PT. The most common reasons for refusing PT were "surgery is inevitable" (44%) and "unlikely to improve pain" (29%). CONCLUSION: Patients with end-stage hip and knee osteoarthritis who are otherwise candidates for surgery appear overwhelmingly opposed to mandatory preoperative PT, mostly due to a lack of perceived efficacy in providing long-term symptom relief compared to total joint arhtroplasty.

Commercial Synovial Antibody Testing is No Better Than Traditional Culture in Identification of Pathogen(s) Causing Periprosthetic Joint Infection.

BACKGROUND: Identification of infective organism causing periprosthetic joint infections (PJIs) is crucial to tailor the best combination of surgical and antimicrobial treatment. Traditional culture, with all its limitations, has been utilized for this purpose. A synovial fluid antibody assay against some common pathogens has been introduced by a commercial entity recently. This study aimed to determine if the antibody testing could be used as a proxy to traditional culture, and whether it provided additional information, in the setting of PJI. METHODS: A retrospective study was conducted of patients who underwent revision total hip and knee arthroplasty between January 2019 and 2020. Aspirated synovial fluid was sent for analyses including the commercial antibody testing. All patients had samples harvested for culture per standard of care. Results of the antibody testing and culture, in terms of concordance, were compared. Receiver operating characteristic curve and Youden's criterion were used to compare the 2 methods. RESULTS: A total of 419 patients were included. Using the International Consensus Meeting criteria as reference standard for PJI, antibody testing had a sensitivity and specificity of 40.5% and 93.4%, respectively. There were 59.5% false negative results with antibody testing compared with 50% for culture. Of the 12 patients who had positive results in both tests, 5 (41.7%) had discordant pathogens identified in each test. CONCLUSION: Synovial fluid antibody testing does not provide clinical benefit when compared to traditional cultures for PJI diagnosis. The antibody testing had a low sensitivity and a high rate of discordance with culture, when both tests were positive.

Stability, edge passivation effect, electronic and transport properties of POPGraphene nanoribbons.

POPGraphene is a theoretically predicted 2D carbon allotrope which presents a unit cell with 5-8-5 carbon rings. It presents metallic behavior and has a low diffusion energy barrier, which suggests applications as an anode material in batteries. Motivated by the fact that nanoribbons present different properties to their 2D counterparts, in this work two kinds of POPGraphene nanoribbons were proposed, with (POPGNRH) and without (POPGNR) hydrogen edge passivation, and their electronic and transport properties were investigated, in order to characterize them and verify the influence of hydrogen edge passivation. Density functional theory was employed for structure optimization and combined with the Non-Equilibrium Green's Function to obtain the electronic transport properties. We predict that both nanoribbons are stable and can be obtained experimentally. Furthermore, hydrogen passivation reduces the bands around the Fermi level and shift them toward the region of negative energies, which can be seen from the presence of NDR in the transport properties of the hydrogenated device. The electronic transport properties suggest that POPGNR shows Field effect transistor behavior in the analyzed range and POPGNRH shows the same behavior, but in the range of -0.70 V to 0.70 V. Also, due to the presence of NDR, POPGNRH presents Resonant Tunneling Diode behavior in the range of ±0.70 V to ±1.00 V. Therefore, the results suggest applications for both nanoribbons in the field of molecular electronics.

Quantum Chemical-Guided Steglich Rearrangement of Azlactones and Isoxazolones.

The theoretical-guided evaluation of the Steglich rearrangement of azlactones and isoxazolones allowed the determination of the reactivity patterns in these heterocycles, including the factors that drive the regioselectivity toward both possible sites. These results allowed the first experimental report on the regioselective Steglich rearrangement of isoxazolones, affording the nitrogen- or carbon-acyloxy adducts.

Use of Closed Incisional Negative Pressure Wound Therapy After Revision Total Hip and Knee Arthroplasty in Patients at High Risk for Infection: A Prospective, Randomized Clinical Trial.

BACKGROUND: Continuous wound drainage after arthroplasty can lead to the development of a periprosthetic joint infection. Closed incisional negative pressure wound therapy (ciNPWT) has been reported to help alleviate drainage and other wound complications. The purpose of this prospective randomized controlled trial is to compare the use of ciNPWT with our standard of care dressing in revision arthroplasty patients who were at high risk to develop wound complications. METHODS: A total of 160 patients undergoing elective revision arthroplasty were prospectively randomized to receive either ciNPWT or a silver-impregnated occlusive dressing after surgery in a single institution. Patients were included if they had at least 1 risk factor for developing wound complication(s): wound complication, readmission, and reoperation rates were collected at 2, 4, and 12 weeks postoperatively. RESULTS: The postoperative wound complication rate was significantly higher in the control cohort compared to the ciNPWT cohort (19 [23.8%] vs 8 [10.1%], P = .022). There was no significant difference between the control and ciNPWT cohorts in terms of readmissions (19 [23.8%] vs 16 [20.3%], P = .595). Reoperation rate was higher in controls compared to ciNPWT patients (10 [12.5%] vs 2 [2.5%], P = .017). After adjusting for the history of a prior periprosthetic joint infection and inflammatory arthritis, the ciNPWT cohort had a significantly decreased wound complication rate (odds ratio 0.28, 95% confidence interval 0.11-0.68). CONCLUSION: ciNPWT may decrease the rate of postoperative wound complications in patients who are at an increased risk of such wound issues after revision arthroplasty.

A Comparison of Pain Management Protocols Following Total Knee Arthroplasty: Femoral Nerve Block versus Periarticular Injection of Liposomal Bupivacaine with an Adductor Canal Block.

BACKGROUND: Total knee arthroplasty (TKA) results in significant postoperative pain and a demanding postoperative path for recovery. This study was conducted to determine whether a femoral nerve block (FNB) or a periarticular injection of liposomal bupivacaine with an adductor canal block (LB+ACB) is superior for pain management. MATERIALS AND METHODS: A total of 557 consecutive primary TKA cases performed at a single hospital between 2010-2014 were retrospectively reviewed. After enrollment criteria were met, 390 cases remained (FNB=181, LB+ACB=209). Inpatient and post-discharge variables related to pain, narcotic use, healthcare resource utilization, and cost were compared. RESULTS: There were no significant differences in demographics between the two groups. There was also no significant difference in inpatient postoperative pain between the two groups. The FNB group consumed fewer narcotics overall compared to the LB+ACB group (p<0.001). However, the LB+ACB group experienced fewer opioid-related adverse events (p<0.001). The LB+ACB group had a shorter length of stay (p<.001), fewer readmissions (p=0.017) and reoperations (p=0.025), and lower costs (p<0.001). DISCUSSION: LB+ACB proved to be an equally effective postoperative TKA pain management tool compared to FNB while displaying superiority in other increasingly important areas such as length of stay and cost. The larger amount of narcotic consumption is a concern, however, and there may be a small population of patients for whom LB+ACB is not the best option.

Synovial Cytokines and the MSIS Criteria Are Not Useful for Determining Infection Resolution After Periprosthetic Joint Infection Explantation.

BACKGROUND: Diagnosing periprosthetic joint infection (PJI) requires a combination of clinical and laboratory parameters, which may be expensive and difficult to interpret. Synovial fluid cytokines have been shown to accurately differentiate septic from aseptic failed total knee (TKA) and hip (THA) arthroplasties. However, after first-stage explantation, there is still no reliable test to rule out PJI before a second-stage reimplantation procedure. QUESTIONS/PURPOSES: (1) Which synovial fluid cytokines have the highest diagnostic accuracy for PJI? (2) Which cytokine shows the greatest decrease associated with the resolution of infection in the same patient between explantation and subsequent reimplantation of an infected arthroplasty? (3) What is the accuracy of synovial fluid cytokines and the Musculoskeletal Infection Society (MSIS) criteria to rule out PJI after first-stage explantation? (4) What are the most studied synovial fluid cytokines for diagnosing PJI as reported in the literature and what are their cumulative diagnostic accuracy? METHODS: Between May 2013 and March 2014, 104 patients with painful THA and TKA evaluated for possible PJI were included in our study. Of these, 90 (87%) had cytokine levels measured from synovial fluid samples collected as part of this prospective study (n = 33 hips, n = 57 knees). A second group of 35 patients (n = 36 samples) who presented during the same time period with an antibiotic spacer also had synovial cytokines measured before second-stage reimplantation. For the first group of 90 patients, the MSIS definition classified each joint at the time of surgery as infected (n = 31) or not infected (n = 59) and was used as the standard to test the accuracy in diagnosing PJI. Of the 35 patients with synovial marker data before second-stage surgery, 15 patients had cytokine measurements both at explantation and reimplantation and were used to quantify the change between stages. The reimplantation group had a minimum 1-year followup (with four [11%] patients lost to followup) and was classified into successful or failed treatment based on Delphi-based consensus data and was used to test the accuracy in detecting infection resolution at reimplantation. RESULTS: Interleukin (IL)-1ß and interferon-γ demonstrated the highest diagnostic utility (area under the curve 0.92, 0.91, respectively); IL-1ß and IL-6 had the highest sensitivities (0.90 [95% confidence interval {CI}, 0.74-0.98] and 0.81 [0.63-0.93]). As a measure of infection resolution, IL-1ß had the greatest decrease (12.4-fold; level at explantation: 232.4 [range, 23.1-1545.7]; level at reimplantation: 18.8 (range 1.2-298.9); mean difference: 325.5 [95% CI, 65.0-596.0]; p = 0.0001), and IL-6 had a nearly similar decrease (11.2-fold; level at explantation: 228.1 [range, 10,158.4-182,725.0]; level at reimplantation: 2518.2 [range, 10.4-41,319.3]; mean difference: 33,176.0 [95% CI, 7543.6-58,808.3]; p < 0.0001). Cytokines and MSIS criteria had low sensitivity to rule out infection in a joint treated for PJI. CONCLUSIONS: IL-6 and IL-1ß demonstrated high sensitivities to diagnose PJI and showed the greatest decrease between first and second stages, which may potentially be used to monitor treatment response to PJI. However, cytokines and MSIS criteria had low sensitivity to rule out infection before reimplantation. LEVEL OF EVIDENCE: Level III, diagnostic study.

The Reamer-Irrigator-Aspirator System: A Review.

The reamer-irrigator-aspirator (RIA) system has been recently developed to decrease the incidence of osseous thermal necrosis and fat embolism associated with intramedullary reaming of long bones in trauma cases. This is achieved by continuous irrigation and suction. Recently, the use of RIA has been expanded to harvest bone graft and debride the medullary canal of long bones in cases of osteomyelitis and intramedullary tumors. Additionally, the collection system of this device has been utilized for its ability to capture bone graft and marrow aspirate. The purpose of this study is to report a comprehensive literature review on the: 1) use of RIA for canal reaming prior to intramedullary nailing; 2) use of RIA for the treatment of intramedullary osteomyelitis of long bones; 3) use of RIA for bone graft harvesting; 4) osteogenic potential of the RIA aspirate; and 5) future applications of the RIA system.

Enhanced neutrophil phagocytic capacity in rheumatoid arthritis related to the autoantibodies rheumatoid factor and anti-cyclic citrullinated peptides.

BACKGROUND: There is no consensus on the mechanisms by which anti-cyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factor (RF) influence the pathogenesis of rheumatoid arthritis (RA). The current study verified if the presence of RF or anti-CCP is associated with phagocytic capacity and reactive oxygen species (ROS) production by phagocytes in RA patients to better clarify the role played by these antibodies in pathogenesis of the disease. METHODS: A cohort of 30 RA patients followed from early stages of the disease were characterized by positivity for RF or anti-CCP, disease activity score (DAS-28), health assessment questionnaire (HAQ), use of synthetic or biologic therapy, lifestyle, comorbidities and radiographic erosions. Phagocytic capacity against Saccharomyces cerevisiae and superoxide anion production were assessed in RA patients and compared with 20 healthy controls. Phagocytic capacity and superoxide anion production were also compared between RF- and anti-CCP-positive and -negative RA patients. RESULTS: Anti-CCP- and RF-positive RA patients had higher neutrophil phagocytic capacity than anti-CCP- (p = 0.005) and RF (p = 0.005)-negative individuals through pattern-recognition receptors. As assessed via pattern recognition or opsonin receptors, neutrophils and monocytes from RA patients presented overall higher phagocytic capacity than neutrophils and monocytes from healthy controls (p < 0.05). Furthermore, RA patients also showed a higher capacity for producing cytotoxic oxygen radicals (p = 0.0026). Phagocytosis and superoxide anion production did not correlate with any of the clinical variables analyzed in this study. CONCLUSIONS: This study showed increased phagocytosis by neutrophils in RA patients who were positive for anti-CCP and RF autoantibodies. Furthermore, there was an overall hyperactivation of the phagocytes in RA patients. Our data suggest that anti-CCP and RF may indirectly enhance the inflammation cascade involving neutrophils and may indirectly sustain tissue damage in RA. Targeting the production of these autoantibodies may be a promising strategy in the management of RA.

Biotransformation of 1-nitro-2-phenylethane [Formula: see text] 2-phenylethanol from fungi species of the Amazon biome: an experimental and theoretical analysis.

CONTEXT: Natural products and their biotransformation procedures are a powerful source of new chromophores with potential applications in fields like biology, pharmacology and materials science. Thus, this work discusses about the extraction procedure of 1-nitro-2-phenylethane (1N2PE) from Aniba canelilla, its biotransformation setup into 2-phenylethanol (2PE) using four fungi, Lasiodiplodia caatinguensis (phytopathogenic fungus from Citrus sinensis), Colletotrichum sp. (phytopathogenic fungus from Euterpe oleracea), Aspergillus flavus and Rigidoporus lineatus isolated from copper mining waste located in the interior of the Brazilian Amazon. A detailed experimental and theoretical vibrational analysis (IR and Raman) have allowed us to perform some charge transfer effects on the title compounds (push-pull effect) by monitoring specific vibrational modes of their electrophilic and nucleophilic molecular sites. The solvent interactions promote molecular conformations that affect the vibrational spectra of the donor and acceptor groups, as can be seen comparatively in the gas and aqueous solution spectra, an effect possibly related to the bathochromic shift in the calculated optical spectrum of the compounds. The nonlinear optical behavior shows that while the solvent reduces the response of 1N2PE, the response of 2PE increases the optical parameters, which presents low refractive index (n) and first hyperpolarizability. ([Formula: see text]) is almost eight times that reported for urea (42.79 a.u.), a common nonlinear optical material. Furthermore, the bioconversion goes from an electrophilic to a nucleophilic compound, affecting its molecular reactivity. METHODS: 1N2PE was obtained from Aniba canelilla, whose essential oil is constituted of [Formula: see text] of 2PE. The A. canelilla essential oil was extracted under hydrodistillation. The biotransformation reactions were performed in autoclaved liquid media (100 mL) composed of malt extract (2%) in 250 mL Erlenmeyer flask. Each culture was incubated in an orbital shaker (130 rpm) at [Formula: see text]C during 7 days and after that, 50 mg of 1N2PE (80%) were diluted in 100 [Formula: see text]L of dimethylsulfoxide (DMSO) and added to the reactions flasks. Aliquots (2 mL) were removed using ethyl acetate (2 mL) and analyzed by GC-MS (fused silica capillary col1umn, Rtx -5MS 30 m [Formula: see text] 0.25 mm [Formula: see text] 0.25 [Formula: see text]m) in order to determine the amount of 1N2PE biotransformation. FTIR 1N2PE and 2PE spectra were obtained by attenuated total reflectance (ATR), using a Agilent CARY 630 spectrometer, in the spectral region 4000-650 cm[Formula: see text]. The quantum chemical calculations were carried out in the Gaussian 09 program while the DICE code was used to perform the classical Monte Carlo simulations and generate the liquid environment using the classical All-Atom Optimized parameters for Liquid Simulations (AA-OPLS). All nonlinear optical properties, reactive parameters, and electronic excitations were calculated using the Density Functional Theory framework coupled to the standard 6-311++G(d,p) basis set.

SARS-CoV-2 external structures interacting with nanospheres using docking and molecular dynamics.

Coronavirus is caused by the SARS-CoV-2 virus has shown rapid proliferation and scarcity of treatments with proven effectiveness. In this way, we simulated the hospitalization of carbon nanospheres, with external active sites of the SARS-CoV-2 virus (M-Pro, S-Gly and E-Pro), which can be adsorbed or inactivated when interacting with the nanospheres. The computational procedures performed in this work were developed with the SwissDock server for molecular docking and the GROMACS software for molecular dynamics, making it possible to extract relevant data on affinity energy, distance between molecules, free Gibbs energy and mean square deviation of atomic positions, surface area accessible to solvents. Molecular docking indicates that all ligands have an affinity for the receptor's active sites. The nanospheres interact favorably with all proteins, showing promising results, especially C60, which presented the best affinity energy and RMSD values ​​for all protein macromolecules investigated. The C60 with E-Pro exhibited the highest affinity energy of -9.361 kcal/mol, demonstrating stability in both molecular docking and molecular dynamics simulations. Our RMSD calculations indicated that the nanospheres remained predominantly stable, fluctuating within a range of 2 to 3 Å. Additionally, the analysis of other structures yielded promising results that hold potential for application in other proteases.Communicated by Ramaswamy H. Sarma.

A DFT analysis of electronic, reactivity, and NLO responses of a reactive orange dye: the role of Hartree-Fock exchange corrections.

An experimental and theoretical study based on DFT/TD-DFT approximations is presented to understand the nature of electronic excitations, reactivity, and nonlinear optical (NLO) properties of reactive orange 16 dye (RO16), an azo chromophore widely used in textile and pharmacological industries. The results show that the solvent has a considerable influence on the electronic properties of the material. According to experimental results, the absorption spectrum is formed by four intense transitions, which have been identified as [Formula: see text] states using TD-DFT calculations. However, the TD-DFT results reveal a weak [Formula: see text] in the low-lying spectral region. Continuum models of solvation indicate that these states suffer from bathochromic (ca. 15 nm) and hypsochromic shifts (ca. 4 nm), respectively. However, the expected blue shift for the absorption [Formula: see text] is only described using long-range or dispersion-corrected DFT methods. RO16 is classified as a strong electrophilic system, with electrophilicity ω > 1.5 eV. Concerning the nucleophilicity parameter (N), from vacuum to solvent, the environment is active and changes the nucleophilic status from strong to moderate nucleophile (2.0 ≤ N ≤ 3.0 eV). The results also suggest that all electrical constants are strongly dependent on long-range and Hartree-Fock exchange contributions, and the absence of these interactions gives results far from reality. In particular, the results for the NLO response show that the chromophore presents a potential application in this field with a low refractive index and first hyperpolarizability ca. 214 times bigger than the value usually reported for urea (ß = 0.34 × 10- 30 esu), which is a standard NLO material. Concerning the solvent effects, the results indicate that the polarizability increases [Formula: see text] esu from gas to solvent while the first hyperpolarizability is calculated as [Formula: see text] esu, ca. 180%, regarding the vacuum. The results suggest RO16 is a potential compound in NLO applications. Graphical Abstract The frontier molecular orbitals, and the inverse relation between the energy-gap (Egap) and the first hyperpolarizability (ß).

Mass spectrometry applied to diagnosis, prognosis, and therapeutic targets identification for the novel coronavirus SARS-CoV-2: A review.

Mass spectrometry (MS) has found numerous applications in medicine and has been widely used in the detection and characterization of biomolecules associated with viral infections such as COVID-19. COVID-19 is a multisystem disease and, therefore, the need arises to carry out a careful and conclusive assessment of the pathophysiological parameters involved in the infection, to develop an effective therapeutic approach, assess the prognosis of the disease, and especially the early diagnosis of the infected population. Thus, the urgent need for highly accurate methods of diagnosis and prognosis of this infection presents new challenges for the development of laboratory medicine, whose methods require sensitivity, speed, and accuracy of the techniques for analyzing the biological markers involved in the infection. In this context, MS stands out as a robust analytical tool, with high sensitivity and selectivity, accuracy, low turnaround time, and versatility for the analysis of biological samples. However, it has not yet been adopted as a frontline clinical laboratory technique. Therefore, this review explores the potential and trends of current MS methods and their contribution to the development of new strategies to COVID-19 diagnosis and prognosis and how this tool can assist in the discovery of new therapeutic targets, in addition, to comment what could be the future of MS in medicine.

A Combined Molecular Docking and Density Functional Theory Nuclear Magnetic Resonance Study of Trans-Dehydrocrotonin Interacting with COVID-19 Main Protease and Severe Acute Respiratory Syndrome Coronavirus 2 3C-Like Protease.

For the development of drugs that treat SARS-CoV-2, the fastest way is to find potential molecules from drugs already on the market. Unfortunately, there is currently no specific drug or treatment for COVID-19. Among all structural proteins in SARS-CoV, the spike protein is the main antigenic component responsible for inducing host immune responses, neutralizing antibodies, and/or protecting immunity against virus infection. Molecular docking is a technique used to predict whether a molecule will bind to another. It is usually a protein to another or a protein to a binding compound. Natural products are potential binders in several studies involving coronavirus. The structure of the ligand plays a fundamental role in its biological properties. The nuclear magnetic resonance technique is one of the most powerful tools for the structural determination of ligands from the origin of natural products. Nowadays, molecular modeling is an important accessory tool to experimentally got nuclear magnetic resonance data. In the present work, molecular docking studies aimed is to investigate the limiting affinities of trans-dehydrocrotonin molecule and to identify the main amino acid residues that could play a fundamental role in their mechanism of action of the SARS-CoV spike protein. Another aim of this work is all about to evaluate 10 hybrid functionalities, along with three base pairs using computational programs to discover which ones are more reliable with the experimental result the best computational method to study organic compounds. We compared the results between the mean absolute deviation (MAD) and root-mean-square deviation (RMSD) of the molecules, and the smallest number between them was the best result. The positions assumed by the ligands in the active site of the spike glycoprotein allow assuming associations with different local amino acids.

Correlation between clinical evaluation of liver size versus ultrasonography evaluation according to body mass index (BMI) and biotypes.

BACKGROUND: Body weight may influence liver size. AIM: To determine the correlation between clinical and ultrasound evaluation of the liver size according to body mass index (BMI). MATERIAL AND METHODS: A cross-sectional study of 81 subjects aged 25 ± 6 years (43 females). Two percussion measurements were taken and ultrasonography was performed on the same site demarcated by percussion. RESULTS: Mean BMI was 23 ± 4 kg/m². Nineteen individuals (23.5%) had a BMI ≥ 25 kg/m². There was a significant difference between the values of liver size obtained by clinical and ultrasound methods. The correlation coefficient between the liver size obtained by clinical and ultrasound methods was 0.419 (p < 0.01). No significant differences in liver size were observed, between subjects with a BMI below or over 25 kg/m². In all subjects, regardless of BMI, there was a statistically significant difference between the mean sizes obtained by both methods. The correlation coefficients between both methods in subjects with a BMI ≤ 25 Kg/m² and their counterparts with higher BMI were 0.47 and 0.03, respectively. CONCLUSIONS: There are significant differences in liver size obtained by clinical examination and ultrasound. Only in subjects with BMI ≤ 25 kg/m², the correlation between the two techniques is significant.

Nb2O5 supported in mixed oxides catalyzed mineralization process of methylene blue.

Heterogeneous photocatalysis has become a significant green technology for water treatment. The application of Nb2O5 catalyst for the photodegradation of contaminants has merged as an important tool to this process. Furthermore, it is known that catalytic phases supported on metal oxides are an alternative method for enhancing its activity. In this work, supported Nb2O5 on mixed oxides as catalyst was applied to degrade methylene blue dye, leading to almost 100% of dye degradation without the need of any additives, after only three hours of sunlight exposure. The effect of catalyst concentration, exposure time and light source were investigated. The best catalyst activity was found at 1.5 g L-1 and for higher catalyst concentrations the degradation was kept constant. Plausible intermediates of this degradation process were observed and characterized by NMR, LC/MS and CZE techniques. After degradation, the catalyst was recovered and could be further re-applied in other three reaction cycles without significant loss of catalytic activity.