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BACKGROUND & OBJECTIVES: Sarcopenia is a morbi-mortality risk factor in digestive surgery, though its impact after major hepatectomy (MH) remains unknown. This prospective pilot study investigated whether volume and function of a regenerating liver is influenced by body composition. METHODS: From 2011 to 2016, 125 consecutive patients had computed tomography and 99mTc-labelled-mebrofenin SPECT-scintigraphy before and after MH at day 7 and 1 month for measurements of liver volumes and functions. L3 vertebra muscle mass identified sarcopenia. Primary endpoint was the impact of sarcopenia on regeneration capacities (i.e. volume/function changes and post-hepatectomy liver failure (PHLF) rate). Secondary endpoint was 3-month morbi-mortality. RESULTS: Sarcopenic patients (SP; N = 69) were significantly older than non-sarcopenic (NSP), with lower BMI and more malignancies, but with comparable liver function/volume at baseline. Postoperatively, SP showed higher rates of ISGLS_PHLF (24.6 % vs 10.9 %; p = 0.05) but with comparable rates of severe morbidity (23.2 % vs 16.4 %; p = 0.35), overall (8.7 % vs 3.6 %; p = 0.3) and PHLF-related mortality (8,7 % vs 1.8 %; p = 0.075). After matching on the extent of resection or using propensity score, regeneration and PHLF rates were similar. CONCLUSION: This prospective study using first sequential SPECT-scintigraphy showed that sarcopenia by itself does not affect liver regeneration capacities and short-term postoperative course after MH.
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Compuestos de Anilina , Glicina , Hepatectomía , Regeneración Hepática , Sarcopenia , Tomografía Computarizada de Emisión de Fotón Único , Tomografía Computarizada por Rayos X , Humanos , Sarcopenia/diagnóstico por imagen , Sarcopenia/etiología , Sarcopenia/complicaciones , Estudios Prospectivos , Masculino , Femenino , Regeneración Hepática/fisiología , Anciano , Persona de Mediana Edad , Proyectos Piloto , Tamaño de los Órganos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/diagnóstico por imagen , Radiofármacos , Compuestos de Organotecnecio , Iminoácidos , Fallo Hepático/diagnóstico por imagen , Fallo Hepático/etiología , Fallo Hepático/cirugíaRESUMEN
The adsorption property of the costless green cellulose acetate (CA) was boosted by the dual modifications: inner modification by incorporating carboxylated graphene oxide (COOH-GO) into the CA spheres and outer modification by the surface modification of the COOH-GO@CA spheres by iminodiacetic acid (IDA) for removing Pb(II). The adsorption experiments of the Pb(II) proceeded in a batch mode to evaluate the adsorption property of the COOH-GO@CA@IDA spheres. The maximal Pb(II) adsorption capacity attained 613.30 mg/g within 90 min at pH = 5. The removal of Pb(II) reached its equilibrium within 20 min, and the removal % was almost 100% after 30 min at the low Pb(II) concentration. The Pb(II) adsorption mechanism was proposed according to the kinetics and isotherms studies; in addition, the zeta potential (ZP) measurements and X-ray Photoelectron Spectroscopy (XPS) analysis defined the adsorption pathways. By comparing the XPS spectra of the authentic and used COOH-GO@CA@IDA, it was deduced that the contributed chemical adsorption pathways are Lewis acid-base, precipitation, and complexation. The zeta potential (ZP) measurements demonstrated the electrostatic interaction participation in adsorbing the cationic Pb(II) species onto the negatively charged spheres (ZP = 14.2 mV at pH = 5). The unique channel-like pores of the COOH-GO@CA@IDA spheres suggested the pore-filling mechanism of Pb(II). The promising adsorption results and the superb recyclability character of COOH-GO@CA@IDA enable it to extend of the bench scale to the industrial scale.
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Celulosa , Grafito , Iminoácidos , Plomo , Grafito/química , Plomo/química , Adsorción , Celulosa/química , Celulosa/análogos & derivados , Iminoácidos/química , Porosidad , CinéticaRESUMEN
Given the substantial environmental pollution from industrial expansion, environmental protection has become particularly important. Nowadays, anion exchange membranes (AEMs) are widely used in wastewater treatment. With the use of polyvinyl alcohol (PVA), ethylene-vinyl alcohol (EVOH) copolymer, and methyl iminodiacetic acid (MIDA), a series of cross-linked AEMs were successfully prepared using the solvent casting technique, and the network structure was formed in the membranes due to the cross-linking reaction between PVA/EVOH and MIDA. Fourier transform infrared spectrometer, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy were used to analyze the prepared membranes. At the same time, its comprehensive properties which include water uptake, linear expansion rate, ion exchange capacity, thermal stability, chemical stability, and mechanical stability were thoroughly researched. In addition, diffusion dialysis performance in practical applications was also studied in detail. The acid dialysis coefficient (UH+) ranged from 10.2 to 35.6 × 10-3 m/h. Separation factor (S) value ranged from 25 to 38, which were all larger than that of the commercial membrane DF-120 (UH+: 8.5 × 10-3 m/h, S: 18.5). The prepared membranes had potential application value in acid recovery.
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Membranas Artificiales , Alcohol Polivinílico , Alcohol Polivinílico/química , Iminoácidos/química , Difusión , Purificación del Agua/métodos , Diálisis/métodos , Intercambio Iónico , Aniones/química , Polivinilos/químicaRESUMEN
Supramolecular metallogels combine the rheological properties of gels with the color, magnetism, and other properties of metal ions. Lanthanide ions such as Eu(III) can be valuable components of metallogels due to their fascinating luminescence. In this work, we combine Eu(III) and iminodiacetic acid (IDA) into luminescent hydrogels. We investigate the tailoring of the rheological properties of these gels by changes in their metal:ligand ratio. Further, we use the highly sensitive Eu(III) luminescence to obtain information about the chemical structure of the materials. In special, we take advantage of computational calculations to employ an indirect method for structural elucidation, in which the simulated luminescent properties of candidate structures are matched to the experimental data. With this strategy, we can propose molecular structures for different EuIDA gels. We also explore the usage of these gels for the loading of bioactive molecules such as OXA, observing that its aldose reductase activity remains present in the gel. We envision that the findings from this work could inspire the development of luminescent hydrogels with tunable rheology for applications such as 3D printing and imaging-guided drug delivery platforms. Finally, Eu(III) emission-based structural elucidation could be a powerful tool in the characterization of advanced materials.
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Europio , Hidrogeles , Europio/química , Hidrogeles/química , Luminiscencia , Iminoácidos/química , Reología , Sustancias Luminiscentes/química , Ligandos , Geles/químicaRESUMEN
Bilothorax, an exudative pleural effusion due to the accumulation of bile. It is also called cholethorax or thoracobilia and was initially reported in 1971. Here, we report a rare case of an elderly male presenting with bilateral bilothorax due to esophageal rupture. A 78-year-old man with multiple medical ailments presented to the emergency room (ER) with a severe episode of vomiting accompanied by a popping sound, respiratory distress, and right sided chest pain. The patient had tachycardia, BP of 101/89 mm Hg, and tachypnea. Computed tomography scan of the chest and abdomen revealed air adjacent to the esophagus, suggesting perforation, atelectasis of right lung, and bilateral pleural effusion (R > L). However, an esophagram did not reveal any perforation. Right-sided chest tube drained dark green bilious fluid. The day after admission, he experienced hemodynamic compromise and hypoxemia requiring intubation, along with fluids and inotropes support. Diagnosis of bilateral bilothorax complicated by hypoxemic respiratory failure with septic shock was made. Cultures were drawn, and empiric antibiotics were started. Nuclear hepatobiliary scan (HIDA) was performed to rule out a hepatobiliary fistula. Results showed reflux activity in the stomach, and distal esophageal leak was identified. Gastrojejunal stenting was performed. However, after prolonged intubation, the family decided on terminal extubation, and he died while receiving hospice care. This case highlights the rarity of bilateral bilothorax, where the HIDA scan played a crucial role in identifying an esophageal leak as the underlying cause, despite normal esophagram results. This condition necessitates prompt diagnosis and aggressive therapeutic interventions.
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Iminoácidos , Derrame Pleural , Humanos , Masculino , Anciano , Derrame Pleural/etiología , Esófago/diagnóstico por imagen , Tomografía Computarizada por Rayos X , BilisRESUMEN
OBJECTIVES: To determine if three new simplified equations for measurement of free mebrofenin clearance give similar results to the equations defined by Ekman et. al ., and to evaluate the properties of all four methods. Regional mebrofenin clearance has been used to predict future remnant liver function and liver failure after regional liver therapy, such as partial hepatic resection. METHODS: The means, standard deviations, and correlations of the free mebrofenin clearance measured by the Ekman method and the three simplified methods were compared in a consecutive series of 26 studies in 20 patients. The fractional change in the blood and free mebrofenin activities were compared, and integrals of normalized blood and free mebrofenin ("effective times") were compared. RESULTS: The average percent free mebrofenin clearance for the Ekman and the first, second and third simplified methods were 13.62 ± 2.88%/min, 12.98 ± 2.97%/min, 12.52 ± 2.81%/min and 15.03 ± 2.27%/min, respectively. The correlations of the new methods with Ekman were 0.97, 0.93 and 0.93. The fractional changes during the measurement interval for the blood and free mebrofenin activities were 0.381 ± 0.065 and 0.329 ± 0.062, difference 0.052, P < 0.5. The integrals of normalized blood and free mebrofenin activities were 2.566 ± 0.160 min and 2.661 ± 0.158 min, difference of 0.094 min and P < 0.05. CONCLUSIONS: The results of the three new methods were similar to the Ekman method. The first simplified method was identified as the lead method for clinical validation in a larger population.
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Glicina , Hígado , Compuestos de Organotecnecio , Humanos , Cintigrafía , Pruebas de Función Hepática , Compuestos de Anilina , IminoácidosRESUMEN
BACKGROUND: Studies have shown that patients with abdominal pain and biliary dyskinesia (low ejection fraction <35 â%) have significant improvement of symptoms following laparoscopic cholecystectomy, but there is lack of evidence that demonstrates whether patients with biliary symptoms and a normal ejection fraction (>35 â%) will have similar results. METHODS: Retrospective, single center study of patients with biliary pain and negative workup, including HIDA with EF>35 â%, who were treated with laparoscopic cholecystectomy from 2017 to 2022. RESULTS: There were 117 total patients. The mean age was 45.49 â± â15.5 years and 101 (86 â%) were female. 101 (86 â%) of patients underwent a right upper quadrant ultrasound, 91 had normal findings, 9 difficult to visualize anatomy and 1 had adenomyomatosis. All patients had a normal HIDA scan and ejection fraction 104 (89 â%) of patients followed up in clinic within 30 days of surgical intervention. 87 (84 â%) reported resolution of pre-operative symptomatology after surgical intervention. There was no statistically significant correlation between pain with CCK administration during HIDA (p â= â0.803) scan or ejection fraction (p â= â0.0977) with resolution of symptoms. CONCLUSIONS: Laparoscopic cholecystectomy appears to be a beneficial intervention for patients with abdominal pain and normokinetic biliary disease. Offering surgical intervention early on can potentially save patients from exhaustive diagnostic investigations and possibly misdiagnosis.
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Discinesia Biliar , Colecistectomía Laparoscópica , Enfermedades de la Vesícula Biliar , Humanos , Femenino , Adulto , Persona de Mediana Edad , Masculino , Colecistectomía Laparoscópica/efectos adversos , Colecistectomía Laparoscópica/métodos , Estudios Retrospectivos , Iminoácidos , Discinesia Biliar/diagnóstico , Discinesia Biliar/cirugía , Enfermedades de la Vesícula Biliar/cirugía , Dolor Abdominal/etiología , Resultado del TratamientoRESUMEN
This study aimed to extract collagen-I from lamb feet (LF) and examine the effects of ultrasound treatment on the structural and molecular characteristics of the collagen. Compared to ultrasonic bath treatment and conventional extraction methods, ultrasonic probe (USP) treatment significantly increased the collagen content of the extract (p < 0.05). The electrophoretic profiles confirmed the presence of α- and ß-chains, indicating it as type I. Furthermore, X-ray diffraction, Fourier-transform infrared spectroscopy, and circular dichroism spectra analyses revealed that the extraction method did not adversely affect the triple helix structure of the collagen. Moreover, the fibrillar structure of the collagen samples was verified through scanning electron microscopy analyses. Notably, the LF collagen exhibited a high thermal denaturation temperature owing to its elevated imino acid content. The collagen samples exhibited high solubility in acidic pH but low solubility in high salt concentrations. The present findings signified that sonication with USP can effectively enhance the yield of collagen from LF without compromising its quality. PRACTICAL APPLICATION: This study showed that ultrasonication enhanced the collagen concentration without disturbing the integrity of lamb feet collagen. We expect that lamb feet collagen can be used for industrial processes and consumer products thanks to unique product properties.
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Colágeno Tipo I , Colágeno , Animales , Ovinos , Colágeno Tipo I/química , Colágeno/química , Iminoácidos , SolubilidadRESUMEN
Surimi industry produces a large quantity of byproducts that are currently being utilized to produce low-value commodities. This study aims to extract gelatin from pink perch skin and bone obtained from the surimi industry using a green single-step extraction method. In addition to using a green solvent, that is, acetic acid, the new method combines the multiple steps of pre-treatment and hydrolysis into one single-step extraction process. Response surface methodology was used to optimize extraction parameters (pH, temperature, and time) to maximize yield and l-hydroxyproline (l-hyp) content. The optimum condition for gelatin extraction was obtained at pH 3, 75°C, and 30 min. At optimum conditions, gelatin yield and l-hyp content were observed to be 16.07% and 41.26 mg g-1 , respectively. The gelatin obtained at optimized condition was further compared with commercial bovine gelatin (BG) in terms of chemical composition and textural, functional, and rheological properties. The results suggested that the optimized pink perch gelatin had higher protein content (92.06%), better gel strength (251.08 g), higher imino acid (18.01%), and improved textural and functional properties than the commercially available BG. The optimized single-step gelatin extraction method from pink perch skin and bones is a promising, rapid, and efficient method for the production of good-quality gelatin, which can be further used for the development of high-value products such as food formulations. PRACTICAL APPLICATION: Fish gelatin is widely used in food product development. Most of the existing methods of the development of high-value product such as gelatin, use multi-step process and harsh mineral acid, therefore, are time-consuming and harmful to the environment. This study provides a green single-step gelatin extraction method that provides an efficient, rapid, and convenient method of gelatin extraction and a sustainable solution for fish industry byproduct utilization. The data obtained with this laboratory-scale study provides a strong basis for scale-up studies.
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Percas , Animales , Bovinos , Gelatina/química , Solventes , Iminoácidos , ProteínasRESUMEN
Arylthioether functional groups serve as effective electroauxiliaries for tunable oxidations. Herein, we disclose the synthesis of second-generation glutamine building blocks bearing 2,4-dimethoxythiophenyl and 2,4-dichlorothiophenyl-derived electroauxiliaries. These building blocks improve SPPS efficiency and enable fine-tuning of the electrochemical window for selective anodic oxidation reactions in comparison to first-generation 4-methoxythiophenyl- and 4-nitrothiophenyl-substituted variants. Installation onto a segment of involucrin, a protein component of human skin, emphasizes the practical application of the new building blocks for iterative functionalizations.
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Iminoácidos , Péptidos , Humanos , Oxidación-ReducciónRESUMEN
PURPOSE: We sought to determine the test characteristics of biliary point-of-care ultrasound (POCUS) and to assess the usefulness of obtaining radiology ultrasound (RUS) or cholescintigraphy (HIDA) after biliary POCUS. METHODS: We conducted a retrospective review of emergency department patients who underwent biliary POCUS between May 4, 2018 and November 28, 2021. To be included, patients had to have at least one of the following confirmatory evaluations (considered in this order): surgery, HIDA, RUS, or abdominal CT scan. When a discrepancy existed between the POCUS and the RUS or HIDA, they were compared to a higher criterion standard (if available). RESULTS: Using 348 patients who had a confirmatory evaluation after biliary POCUS, we found the sensitivity and specificity of biliary POCUS for gallstones to be 97.0% (95% CI 92.6 to 99.2%) and 99.5% (95% CI 97.3 to 100%), respectively. For cholecystitis, the sensitivity and specificity were 83.8% (95% CI 72.9 to 91.6%) and 98.6% (95% CI 96.4 to 99.6%), respectively. RUS and POCUS were concordant in 72 (81.8%) of 88 cases in which the patient had both studies while HIDA and POCUS were concordant in 24 (70.6%) of 34 cases. POCUS was deemed correct in at least 50% of discrepant cases with RUS and at least 30% of discrepant cases with HIDA. CONCLUSION: Biliary POCUS has excellent sensitivity and specificity for cholelithiasis; it has lower sensitivity for cholecystitis, but the specificity remains high. Performing a confirmatory RUS or cholescintigraphy after a positive biliary POCUS adds little value, but additional imaging may be useful when POCUS is negative for cholecystitis.
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Colecistitis , Sistemas de Atención de Punto , Humanos , Iminoácidos , Ultrasonografía/métodos , Servicio de Urgencia en HospitalRESUMEN
Organoboron compounds have a wide-range of applications in synthetic methodologies, natural products, and bioactive molecule synthesis. The sensitivity of boronic acid toward most synthetic reagents makes it necessary to introduce a protecting group before its utilization. Benchtop stable MIDA boronates have been found compatible with various common synthetic reagents which opens the doors for the synthesis of various small building blocks, natural products, and bioactive compounds. MIDA boronate compounds have been extensively utilized in Suzuki Miyaura coupling and Iterative cross-coupling reactions for the total synthesis of bioactive molecules and polymerization reactions. Different MIDA boronate compounds like vinyl, acyl, formyl, acrylic, and α-carbonyl MIDA boronates also act as novel synthetic building blocks for various synthetic transformations in organic synthesis. This paper summarizes the importance of MIDA boronate compounds in various aspects of organic chemistry.
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Productos Biológicos , Iminoácidos , Iminoácidos/química , Ácidos Borónicos/química , Técnicas de Química SintéticaRESUMEN
Background and objectives-Chronic viral hepatitis B and C infections are one of the leading causes of chronic liver impairment, resulting in liver fibrosis and liver cirrhosis. An early diagnosis with accurate liver fibrosis staging leads to a proper diagnosis, thus tailoring correct treatment. Both invasive and noninvasive techniques are used in the diagnosis and staging of chronic liver impairment. Those techniques include liver biopsy, multiple serological markers (as either single tests or combined panels), and imaging examinations, such as ultrasound or magnetic resonance elastography. Nuclear medicine probes may also be employed in staging liver fibrosis, although the literature scarcely reports this. The purpose of our study was to investigate whether a dynamic liver scintigraphy with [99mTc]Tc-mebrofenin has any value in staging or grading chronic liver damage. Materials and Methods-We prospectively enrolled patients with chronic viral hepatitis B and C infection referred for liver biopsy. All patient underwent dynamic liver scintigraphy with 99mTc-mebrofenin prior to liver biopsy. Dynamic liver scintigraphy was performed immediately after intravenous tracer injection for 30 min scanning time. Multiple scintigraphy parameters were calculated (whole liver lobe and focal area time to peak (TTP), 30 min to peak ratio (30/peak), whole lobe and focal area slope index in 350 s (slope_350). Liver biopsy took place shortly after imaging. Results-We found that many dynamic scintigraphic parameters are positively or negatively associated with different stages of liver fibrosis. The main parameters that showed most value are the ratio between 30 min and the peak of the dynamic curve (30/peak_dex (ratio)), and liver clearance corrected for body surface area and liver area (LCL_m2_dm2 (%/min/m2/dm2)). Conclusions-Our present study proves that conducting dynamic liver scintigraphies with [99mTc]Tc-mebrofenin has potential value in staging liver fibrosis. The benefits of this method, including whole liver imaging and direct imaging of the liver function, provide an advantage over presently used quantitative imaging modalities.
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Hepatitis Viral Humana , Hepatopatías , Humanos , Iminoácidos , Radiofármacos , Tomografía Computarizada por Rayos X , Hígado/patología , Cirrosis Hepática/complicaciones , Cirrosis Hepática/diagnóstico por imagenRESUMEN
A new method for the synthesis of (hetero)aryl nitriles via iminyl radicals has been developed through the electrochemical oxidative decarboxylation of α-imino-oxy acids. This protocol provides an efficient approach to nitriles with a broad range of functional-group tolerance under ambient conditions and can be applied for one-pot gram-scale synthesis.
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Iminoácidos , Nitrilos , Catálisis , Descarboxilación , Estrés OxidativoRESUMEN
Introduction: Biliary dyskinesia is typically defined as a gallbladder ejection fraction (EF) <35% on hepatobiliary iminodiacetic acid scan with cholecystokinin stimulation (CCK-HIDA) testing. Cholecystectomy often leads to resolution of associated biliary colic symptoms. Alternatively, there is a subset of symptomatic patients with normal gallbladder EF on CCK-HIDA. It has been proposed that pain with CCK injection is more predictive of symptom resolution after cholecystectomy than low gallbladder EF. We reviewed our experience with pediatric patients with positive CCK provocation testing and a normal gallbladder EF in the absence of gallstones. Materials and Methods: We retrospectively reviewed the records of all pediatric patients with normal hepatobiliary iminodiacetic acid EFs (35%-80%) and pain with CCK injection at a tertiary care center between 2016 and 2020. Age, gender, body mass index (BMI), CCK-HIDA results, and pathology analysis were noted. Short- and long-term resolution of symptoms was determined by patient self-reporting at a mean of 3 weeks and 46 months, respectively. Results: Seventeen patients met inclusion criteria. Average age was 15.1 years (range, 12-17 years) with median BMI 24.9 (± 4.9 kg/m2). Mean CCK-HIDA EF was 56.3% (± 11.4%). In total, 62.5% of patients had evidence of chronic cholecystitis and/or cholesterolosis on pathology analysis. Of patients available for short-term and long-term postoperative follow-up, 80% and 83% reported complete or near complete resolution of symptoms, respectively. Conclusions: Normokinetic biliary dyskinesia is poorly understood but appears to be associated with chronic inflammation and cured by surgical intervention. Laparoscopic cholecystectomy results in resolution of symptoms for a majority of patients and should be considered in those with pain with CCK injection despite normal imaging studies. Clinical Trial Registration Number: 1657640-2.
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Discinesia Biliar , Colecistectomía Laparoscópica , Adolescente , Niño , Humanos , Discinesia Biliar/cirugía , Colecistectomía , Colecistectomía Laparoscópica/efectos adversos , Colecistectomía Laparoscópica/métodos , Colecistoquinina , Iminoácidos , Dolor , Estudios RetrospectivosRESUMEN
Malignant pleural mesothelioma (MPM) is one of the intractable cancers that require a more effective therapeutic strategy for clinical practice. Hyaluronic acid (HA) nanogels were prepared by the chelation of cisplatin (CDDP) with different molecular weights of iminodiacetic acid-conjugated hyaluronic acid (HA-IDA). The sizes of the 100, 850, and 2000 kDa HA nanogels were 33, 43, and 44 nm, respectively. MSTO-211H, a human MPM cell line, was more effective in taking up all three HA nanogels compared to AB22, a mouse MPM cell line. In addition, the 850 kDa HA nanogel showed higher anticancer activity against AB22 and MSTO-211H than 100 and 2000 kDa HA nanogels. Furthermore, all the HA nanogels showed a milder cytotoxic effect on normal Met-5A mesothelial cells compared to that exhibited by free CDDP. Finally, the 850 kDa HA nanogel was administrated intrapleurally into both the MSTO-211H xenograft and AB22 allograft mouse models of MPM using an injectable HA-based hydrogel. HA nanogels showed a significant therapeutic effect in both the xenograft and allograft models.
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Cisplatino , Mesotelioma Maligno , Animales , Línea Celular Tumoral , Cisplatino/farmacología , Cisplatino/uso terapéutico , Humanos , Ácido Hialurónico , Iminoácidos , Ratones , NanogelesRESUMEN
Naturally occurring secondary amino acids, with proline as the main representative, contain an alpha-imino group in a cycle that is typically four-, five-, and six-membered. The unique ring structure exhibits exceptional properties-conformational rigidity, chemical stability, and specific roles in protein structure and folding. Many proline analogues have been used as valuable compounds for the study of metabolism of both prokaryotic and eukaryotic cells and for the synthesis of compounds with desired biological, pharmaceutical, or industrial properties. The D-forms of secondary amino acids play different roles in living organisms than the L-forms. They have different metabolic pathways, biological, physiological, and pharmacological effects, they can be indicators of changes and also serve as biomarkers of diseases. In the scientific literature, the number of articles examining D-amino acids in biological samples is increasing. The review summarises information on the occurrence and importance of D- and L-secondary amino acids-azetidic acid, proline, hydroxyprolines, pipecolic, nipecotic, hydroxypipecolic acids and related peptides containing these D-AAs, as well as the main analytical methods (mostly chromatographic) used for their enantiomeric determination in different matrices (biological samples, plants, food, water, and soil).
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Aminoácidos , Iminoácidos , Aminoácidos/química , Iminoácidos/química , Péptidos , Prolina/química , EstereoisomerismoRESUMEN
The rare earth elements being toxic in nature are being accumulated in water bodies as their industrial usage is growing exponentially, thus their efficient separation holds an immense significance. Herein, ligand functionalized metal organic framework (MOF), Phosphonomethyl iminodiacetic acid coordinated at Fe-BTC, was synthesized post-synthetically and incorporated subsequently in polyacrylonitrile polymer to prepare the composite beads via nonsolvent induced-phase-inversion technique for selective adsorption of La(III) from the wastewater in batch and dynamic column mode. XPS NMR, and FTIR were used to establish the interaction between functionalized ligand and unsaturated metal nodes of MOF. The adsorption capacity was 232.5 mg/g and 77.51 mg/g at 298 K of the functionalized MOF and composite beads respectively. Adsorption kinetics followed a pseudo-second order rate equation, and isotherm indicated the best fitting with Langmuir model. The dynamic behavior of the adsorption column packed with MOF/Polymer beads was fairly described by the Thomas model. The breakthrough time of 23.2 h could be attained with 12 cm of bed height and 10 ml/min of flow rate. These MOF/Polymer beads shown the selectivity of La over transitional metals were recycled over 5 times with about 15% loss of adsorption capacity. The findings provide suggestive insights of the potential use of functionalized MOF towards the separation of the rare earth element.
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Estructuras Metalorgánicas , Contaminantes Químicos del Agua , Adsorción , Iminoácidos , Cinética , Aguas Residuales , Contaminantes Químicos del Agua/análisisRESUMEN
Reducing domain divergence is a key step in transfer learning. Existing works focus on the minimization of global domain divergence. However, two domains may consist of several shared subdomains, and differ from each other in each subdomain. In this article, we take the local divergence of subdomains into account in transfer. Specifically, we propose to use the low-dimensional manifold to represent the subdomain, and align the local data distribution discrepancy in each manifold across domains. A manifold maximum mean discrepancy (M3D) is developed to measure the local distribution discrepancy in each manifold. We then propose a general framework, called transfer with manifolds discrepancy alignment (TMDA), to couple the discovery of data manifolds with the minimization of M3D. We instantiate TMDA in the subspace learning case considering both the linear and nonlinear mappings. We also instantiate TMDA in the deep learning framework. Experimental studies show that TMDA is a promising method for various transfer learning tasks.
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Algoritmos , Iminoácidos , MorfolinasRESUMEN
Hepatobiliary iminodiacetic acid (HIDA) scan is one of the principal imaging modalities for the evaluation of the gallbladder and biliary tree. Congenital biliary anomalies are rare and can be difficult to recognize on HIDA scan. They may also mimic other biliary pathology. The purpose of this article is to review the spectrum of congenital gallbladder and biliary anomalies and describe their imaging appearance on HIDA scan. In addition, the diagnostic utility of functional imaging with HIDA when evaluating biliary tract anomalies is described.