Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 178
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Small ; : e2403772, 2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39004855

RESUMO

Rapid economic development has led to oil pollution and energy shortage. Membrane separation has attracted much attention due to its simplicity and efficiency in oil-water-separation. The development of membrane materials with enhanced separation properties is essential to improve the separation-efficiency. Proton exchange membrane fuel cells (PEMFCs) are expected to replace conventional engines due to their high-power-conversion rates and other favorable properties. Anhydrous-proton-conducting materials are vital components of PEMFCs. However, developing stable proton-conducting materials that exhibit high conductivity at varying temperatures remains challenging. Herein, two covalent organic frameworks (COFs) with long-side-chains are synthesized, and their corresponding COF@SSN membranes. Both membranes can effectively separate oil-water mixtures and water-in-oil emulsions. The TFPT-AF membrane achieves a maximum oil-flux of 6.05 × 105 g h-1 m-2 with an oil-water separation efficiency of above 99%, which is almost unchanged after 20 consecutive uses. COF@H3PO4 doped with different ratios of H3PO4 is prepared, the results show that the perfluorocarbon-chain system has  excellent anhydrous proton conductivity , achieving an ultra-high proton-conductivity of 3.98 × 10-1 S cm-1 at 125 °C. This study lays the foundation for tailor-made-functionalization of COF through pre-engineering and surface-modification, highlighting the great potential of COFs for oil-water separation and anhydrous-proton-conductivity.

2.
Small ; 20(16): e2308677, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38009515

RESUMO

Fuel cells offer great promise for portable electricity generation, but their use is currently limited by their low durability, excessive operating temperatures, and expensive precious metal electrodes. It is therefore essential to develop fuel cell systems that can perform effectively using more robust electrolyte materials, at reasonable temperatures, with lower-cost electrodes. Recently, proton exchange membrane fuel cells have attracted attention due to their generally favorable chemical stability and quick start-up times. However, in most membrane materials, water is required for proton conduction, severely limiting operational temperatures. Here, for the first time it is demonstrated that when acidified, PAF-1 can conduct protons at high temperatures, via a unique framework diffusion mechanism. It shows that this acidified PAF-1 material can be pressed into pellets with high proton conduction properties even at high temperatures and pellet thickness, highlighting the processibility, and ease of use of this material. Furthermore, a fuel cell is shown with high power density output is possible using a non-precious metal copper electrode. Acid-doped PAF-1 therefore represents a significant step forward in the potential for a broad-purpose fuel cell due to it being cheap, robust, efficient, and easily processible.

3.
Pharm Res ; 41(3): 595-607, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38383934

RESUMO

PURPOSE: Wet granulation (WG) is one of the most versatile processes to improve blend properties for processing. However, due to its need for moisture and heat, it is often considered not amenable to active pharmaceutical ingredients (APIs) prone to forming hydrates. Despite this claim, little literature exists evaluating the extent to which polymorphic form conversions occur for such API when processed with WG. This work sets out to explore two common WG methods, high-shear (HSG) and fluid-bed (FBG), and two drying processes, tray-drying (TD) and fluid-bed drying (FBD), and evaluate the risk they pose to hydrate form conversion. METHODS: The progression of anhydrous to hydrate form conversion of two model compounds with vastly different solubilities, fexofenadine hydrochloride and carbamazepine, was monitored throughout the various processes using powder X-ray diffraction. The resultant granules were characterized using thermogravimetric analysis, differential scanning calorimetry, BET adsorption, and sieve analysis. RESULTS: FBG and FBD processing resulted in the preservation of the original form of both APIs, while HSG+TD resulted in the complete conversion of the API. The FBD of fexofenadine and carbamazepine granules prepared with HSG resulted in partial and complete re-conversion back to the original anhydrous forms, respectively. CONCLUSION: The drying process is a critical factor in anhydrous form conservation. FBG and FBD yielded better preservation of the initial anhydrous forms. HSG could be an acceptable granulation method for API susceptible to hydrate formation if the API solubility is low. Selecting an FBG+FBD process minimizes API hydrate formation and preserves the original anhydrous form.


Assuntos
Química Farmacêutica , Temperatura Alta , Química Farmacêutica/métodos , Difração de Raios X , Dessecação , Solubilidade , Carbamazepina
4.
Dig Dis Sci ; 69(5): 1889-1896, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38517560

RESUMO

AIM: Endoscopic necrosectomy has become the first-line treatment option for infectious necrotizing pancreatitis (INP), especially walled-off necrosis. However, the problems, including operation-related adverse events (AEs) and the need for multiple endoscopic procedures, have not been effectively addressed. We sought to evaluate the clinical safety and efficacy of anhydrous ethanol-assisted endoscopic ultrasound (EUS)-guided transluminal necrosectomy in INP. METHODS: A single-center observational cohort study of INP patients was conducted in a tertiary endoscopic center. Anhydrous ethanol-assisted EUS-guided transluminal necrosectomy (modified group) and conventional endoscopic necrosectomy (conventional group) were retrospectively compared in INP patients. The technical and clinical success rates, operation time, perioperative AEs, postoperative hospital stay, and recurrent INP rates were analyzed, respectively. RESULTS: A total of 55 patients were enrolled. No statistically significant differences were observed between the two groups regarding baseline characteristics. Compared to patients in the conventional group, patients in the modified group demonstrated significantly reduced times of endoscopic transluminal necrosectomies (1.96 ± 0.89 vs. 2.73 ± 0.98; P = 0.004) and comparable perioperative AEs (P = 0.35). Meanwhile, no statistically significant differences were observed in the technical and clinical success rates (P = 0.92), operation time (P = 0.59), postoperative hospital stay (P = 0.36), and recurrent INP rates (P = 1.00) between the two groups. CONCLUSION: Anhydrous ethanol-assisted EUS-guided transluminal necrosectomy seemed safe and effective in treating INP. Compared with conventional endoscopic transluminal necrosectomy, its advantage was mainly in reducing the number of endoscopic necrosectomies without increasing perioperative AEs.


Assuntos
Endossonografia , Etanol , Pancreatite Necrosante Aguda , Humanos , Pancreatite Necrosante Aguda/cirurgia , Pancreatite Necrosante Aguda/diagnóstico por imagem , Masculino , Feminino , Pessoa de Meia-Idade , Etanol/administração & dosagem , Endossonografia/métodos , Estudos Retrospectivos , Adulto , Resultado do Tratamento , Idoso , Tempo de Internação/estatística & dados numéricos , Ultrassonografia de Intervenção/métodos , Duração da Cirurgia
5.
Skin Res Technol ; 30(3): e13589, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38396354

RESUMO

BACKGROUND: Ketoprofen is a nonsteroidal anti-inflammatory drug used for the treatment of acute and chronic pain associated with inflammatory conditions. This study aims to evaluate the in vitro percutaneous absorption of ketoprofen 10% formulated in proprietary anhydrous and aqueous gels using the Franz skin finite dose model. MATERIALS AND METHODS: The anhydrous gel was initially characterized for cytotoxicity using EpiDerm skin tissue model by cell proliferation assay and Western blot analysis. The Ultra Performance Liquid Chromatography method for measuring ketoprofen was validated and the stability of ketoprofen 10% in the anhydrous gel formulation was evaluated at 5°C and 25°C for 181 days. The percutaneous absorption of ketoprofen was determined using donated human skin. The tissue sections were mounted within Franz diffusion cells. A variable finite dose of each ketoprofen formulation in either anhydrous or aqueous gel was applied to the skin sections and receptor solutions were collected at various time points. RESULTS: Cell proliferation assay showed minimal cell death when EpiDerm skin tissue was exposed to the anhydrous gel for 24 h; the levels of protein markers of cell proliferation were not affected after 17-h exposure. Ketoprofen was stable in the anhydrous gel when stored at 5°C and 25°C. When compounded in the anhydrous and aqueous gels, ketoprofen had mean flux rate of 2.22 and 2.50 µg/cm2 /h, respectively, after 48 h. The drug was distributed to the epidermis and dermis sections of the skin. Both the anhydrous and aqueous gels facilitated the percutaneous absorption of ketoprofen without statistically significant differences. CONCLUSION: The anhydrous gel can be used as a base to facilitate the transdermal delivery of ketoprofen. Although the anhydrous and aqueous gels can deliver a similar amount of ketoprofen, the anhydrous gel (water activity below 0.6) allows for extended default beyond-use-date of compounding preparations.


Assuntos
Cetoprofeno , Humanos , Cetoprofeno/química , Cetoprofeno/metabolismo , Absorção Cutânea , Pele/metabolismo , Anti-Inflamatórios não Esteroides , Administração Cutânea , Géis , Água/metabolismo
6.
Chem Pharm Bull (Tokyo) ; 72(1): 48-55, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38171904

RESUMO

In order to create and offer superior pharmaceuticals for consumers who wish to be relieved of headache and fever as soon as possible, we established HYDROFLASH manufacturing method that enables us to offer fast disintegration tablets containing loxoprofen sodium (LX), which are difficult to disintegrate. As a result of screening excipients, tablets using mannitol showed the fastest disintegration time, about 2 min. From the result of viscosity measurement, we found that LX produced higher viscosity when dissolved in water. This suggests that tablets containing LX disintegrate slower by inhibiting the penetration of water into the tablet due to the viscosity caused of LX. Therefore, we created a manufacturing method to make it easy for water to penetrate the tablet. It is possible to achieve fastest disintegration in about 30 s for tablets containing LX by granulating in a fluidized-bed with spraying of the dispersion of light anhydrous silicic acid (LASA). LX-containing tablets manufactured by the HYDROFLASH method disintegrated immediately after contact with water. Furthermore, it was observed that LASA was uniformly dotted on the surface of tablets by HYDROFLASH method, compared with other manufacturing methods. We considered that by fluidized-bed granulation with LASA dispersion (HYDROFLASH manufacturing method), water permeates through LASA on the tablet surface regardless of viscosity of LX. Futhermore, LX-containing tablets by the HYDROFLASH method showed that the dissolution rate of LX was nearly 100% at 5 min after starting the test. We considered that the initial dissolution became faster because of the fast disintegration.


Assuntos
Excipientes , Dióxido de Silício , Solubilidade , Água
7.
Angew Chem Int Ed Engl ; 63(4): e202317480, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38059405

RESUMO

Wide applications of anhydrous rare-earth (RE) trichlorides RECl3 in organometallic chemistry, for the synthesis of optical and magnetic materials, and as catalysts require a facile approach for their synthesis. The known methods use or produce toxic substances, are complicated and have limited reliability and upscaling. It has been shown that task-specific ionic liquids (ILs) can dissolve many metal oxides without special reaction conditions at moderate temperature, making the metals accessible to downstream chemistry. Using imidazolium chloridoaluminate ILs, pure crystalline anhydrous RECl3 (RE=La-Nd, Sm-Dy) can be synthesized in one step from RE oxides in high yield. The Lewis acidic IL acts as solvent and reaction partner. The by-product [Al4 O2 Cl10 ]2- , which was detected spectroscopically, remains in solution. The reacted IL can be removed quantitatively by washing. ILs with various imidazolium cations and AlCl3 content and the effect of temperature and reaction time were tested.

8.
Chemistry ; 29(31): e202300004, 2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-36935356

RESUMO

Biomimetic synthesis of guanine crystals has been focused on in the last years. However, multi-functional guanine crystals occluded with fluorescent molecules have not been realized in the laboratory. Here, the controllable synthesis of guanine crystal microplatelets with fluorescence and pearlescence was achieved for the first time by incorporating Nile red (NR) or fluorescein isothiocyanate (FITC) molecules into guanine crystals. The synthesized fluorescent guanine crystals are pure ß-phase anhydrous guanine single crystals. Aqueous suspensions with NR- and FITC-doped guanine crystals exhibit distinct pearlescence. The fluorescence intensities of NR and FITC were greatly enhanced after being doped into guanine crystals due to the inhibition of aggregation-caused quenching. Moreover, films composed of fluorescent guanine microplatelets exhibit high diffuse reflection intensity (70 %). This work provides a strategy to synthesize multifunctional materials composed of organic crystals occluded with dyes.

9.
Macromol Rapid Commun ; 44(1): e2200227, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35642732

RESUMO

Superionic anhydrous proton conductors can be obtained from the complexation of nanoscale polyoxometalates (POMs) and poly(ethylene glycol) (PEG) in the "polymer in salt" regime. The reduced energy barrier of H+ hopping is facilitated from the increased H+ concentration and shortened inter-POM distances. POMs with identical structure/size (≈1 nm) but different charge densities are complexed with PEG, respectively, with concentrations ranging from 10 to 60 % wt. Increasing trends of viscosities can be observed with the rising charge densities of POMs due to the increasing confinement strength on PEG substrate from POMs. Fractional Walden rule is further applied to analyze the viscosity and proton conductivity correlations, and microscopic mechanisms of proton conduction for PEG-POM nanocomposites are revealed: 1) ion transport is highly associated with polymer chain dynamic for POMs concentrations ranging from 10 to 30 % wt.; 2) ionic conduction is largely decoupled from chain dynamic of polymer matrix for concentrations ranging from 40 to 60 % wt. with Walden plots shifted to the superionic regime. The decoupling of proton transport from polymer segment dynamics allows the simultaneous enhancements of the nanocomposites' mechanical properties and proton conductions, providing guidelines for the rational design of anhydrous proton conductors with integrated functionalities.


Assuntos
Nanocompostos , Polietilenoglicóis , Polietilenoglicóis/química , Prótons , Polímeros/química , Nanocompostos/química
10.
Int J Mol Sci ; 24(19)2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37834109

RESUMO

Melanogenesis, the intricate process of melanin synthesis, is central to skin pigmentation and photoprotection and is regulated by various signaling pathways and transcription factors. To develop potential skin-whitening agents, we used B16F1 melanoma cells to investigate the inhibitory effects of anhydrous alum on melanogenesis and its underlying molecular mechanisms. Anhydrous alum (KAl(SO4)2) with high purity (>99%), which is generated through the heat-treatment of hydrated alum (KAl(SO4)2·12H2O) at 400 °C, potentiates a significant reduction in melanin content without cytotoxicity. Anhydrous alum downregulates the master regulator of melanogenesis, microphthalmia-associated transcription factor (MITF), which targets key genes involved in melanogenesis, thereby inhibiting α-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis. Phosphorylation of the cAMP response element-binding protein, which acts as a co-activator of MITF gene expression, is attenuated by anhydrous alum, resulting in compromised MITF transcription. Notably, anhydrous alum promoted extracellular signal-regulated kinase phosphorylation, leading to the impaired nuclear localization of MITF. Overall, these results demonstrated the generation and mode of action of anhydrous alum in B16F1 cells, which constitutes a promising option for cosmetic or therapeutic use.


Assuntos
Melaninas , alfa-MSH , Melaninas/metabolismo , alfa-MSH/metabolismo , Monofenol Mono-Oxigenase/metabolismo , Fator de Transcrição Associado à Microftalmia/genética , Fator de Transcrição Associado à Microftalmia/metabolismo , Linhagem Celular Tumoral
11.
Molecules ; 28(3)2023 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-36770756

RESUMO

A practical method of selective alkylation of the third hydroxyl group of disubstituted tert-butyl-calix[4]arenes using anhydrous barium hydroxide as a base was developed in this study. The use of this method in the synthesis of inherently chiral derivatives is shown herein.

12.
Angew Chem Int Ed Engl ; 62(6): e202217240, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36478518

RESUMO

Developing new materials for anhydrous proton conduction under high-temperature conditions is significant and challenging. Herein, we create a series of highly crystalline covalent organic frameworks (COFs) via a pore engineering approach. We simultaneously engineer the pore geometry (generating concave dodecagonal nanopores) and pore surface (installing multiple functional groups such as -C=N-, -OH, -N=N- and -CF3 ) to improve the utilization efficiency and host-guest interaction of proton carriers, hence benefiting the enhancement of anhydrous proton conduction. Upon loading with H3 PO4 , COFs can realize a proton conductivity of 2.33×10-2  S cm-1 under anhydrous conditions, among the highest values of all COF materials. These materials demonstrate good stability and maintain high proton conductivity over a wide temperature range (80-160 °C). This work paves a new way for designing COFs for anhydrous proton conduction applications, which shows great potential as high-temperature proton exchange membranes.

13.
J Transl Med ; 20(1): 295, 2022 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-35764955

RESUMO

BACKGROUND: There is no approved pharmaceutical intervention for Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS). Fatigue in these patients can last for decades. Long COVID may continue to ME/CFS, and currently, it is estimated that up to 20 million Americans have significant symptoms after COVID, and the most common symptom is fatigue. Anhydrous Enol-Oxaloacetate, (AEO) a nutritional supplement, has been anecdotally reported to relieve physical and mental fatigue and is dimished in ME/CFS patients. Here, we examine the use of higher dosage AEO as a medical food to relieve pathological fatigue. METHODS: ME/CFS and Long-COVID patients were enrolled in an open label dose escalating "Proof of Concept" non-randomized controlled clinical trial with 500 mg AEO capsules. Control was provided by a historical ME/CFS fatigue trial and supporting meta-analysis study, which showed average improvement with oral placebo using the Chalder Scale of 5.9% improvement from baseline. At baseline, 73.7% of the ME/CFS patients were women, average age was 47 and length of ME/CFS from diagnosis was 8.9 years. The Long-COVID patients were a random group that responded to social media advertising (Face Book) with symptoms for at least 6 months. ME/CFS patients were given separate doses of 500 mg BID (N = 23), 1,000 mg BID (N = 29) and 1000 mg TID (N = 24) AEO for six weeks. Long COVID patients were given 500 mg AEO BID (N = 22) and 1000 mg AEO (N = 21), again over a six-week period. The main outcome measure was to compare baseline scoring with results at 6 weeks with the Chalder Fatigue Score (Likert Scoring) versus historical placebo. The hypothesis being tested was formulated prior to data collection. RESULTS: 76 ME/CFS patients (73.7% women, median age of 47) showed an average reduction in fatigue at 6 weeks as measured by the "Chalder Fatigue Questionnaire" of 22.5% to 27.9% from baseline (P < 0.005) (Likert scoring). Both physical and mental fatigue were significantly improved over baseline and historical placebo. Fatigue amelioration in ME/CFS patients increased in a dose dependent manner from 21.7% for 500 mg BID to 27.6% for 1000 mg Oxaloacetate BID to 33.3% for 1000 mg TID. Long COVID patients' fatigue was significantly reduced by up to 46.8% in 6-weeks. CONCLUSIONS: Significant reductions in physical and metal fatigue for ME/CFS and Long-COVID patients were seen after 6 weeks of treatment. As there has been little progress in providing fatigue relief for the millions of ME/CFS and Long COVID patients, anhydrous enol oxaloacetate may bridge this important medical need. Further study of oxaloacetate supplementation for the treatment of ME/CFS and Long COVID is warranted. Trial Registration https://clinicaltrials.gov/ct2/show/NCT04592354 Registered October 19, 2020. 1,000 mg BID Normalized Fatigue Data for Baseline, 2-weeks and 6-weeks evaluated by 3 Validated Fatigue Scoring Questionnaires.


Assuntos
Tratamento Farmacológico da COVID-19 , COVID-19 , Síndrome de Fadiga Crônica , Ácido Oxaloacético , COVID-19/complicações , Síndrome de Fadiga Crônica/complicações , Síndrome de Fadiga Crônica/tratamento farmacológico , Feminino , Humanos , Masculino , Fadiga Mental/tratamento farmacológico , Fadiga Mental/virologia , Pessoa de Meia-Idade , Ácido Oxaloacético/uso terapêutico , Síndrome de COVID-19 Pós-Aguda
14.
J Inherit Metab Dis ; 45(4): 719-733, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35358327

RESUMO

Patient registries for rare diseases enable systematic data collection and can also be used to facilitate postauthorization safety studies (PASS) for orphan drugs. This study evaluates the PASS for betaine anhydrous (Cystadane), conducted as public private partnership (PPP) between the European network and registry for homocystinurias and methylation defects and the marketing authorization holder (MAH). Data were prospectively collected, 2013-2016, in a noninterventional, international, multicenter, registry study. Putative adverse and severe adverse events were reported to the MAH's pharmacovigilance. In total, 130 individuals with vitamin B6 nonresponsive (N = 54) and partially responsive (N = 7) cystathionine beta-synthase (CBS) deficiency, as well as 5,10-methylenetetrahydrofolate reductase (MTHFR; N = 21) deficiency and cobalamin C (N = 48) disease were included. Median (range) duration of treatment with betaine anhydrous was 6.8 (0-9.8) years. The prescribed betaine dose exceeded the recommended maximum (6 g/day) in 49% of individuals older than 10 years because of continued dose adaptation to weight; however, with disease-specific differences (minimum: 31% in B6 nonresponsive CBS deficiency, maximum: 67% in MTHFR deficiency). Despite dose escalation no new or potential risk was identified. Combined disease-specific treatment decreased mean ± SD total plasma homocysteine concentrations from 203 ± 116 to 81 ± 51 µmol/L (p < 0.0001), except in MTHFR deficiency. Recommendations for betaine anhydrous dosage were revised for individuals ≥ 10 years. PPPs between MAH and international scientific consortia can be considered a reliable model for implementing a PASS, reutilizing well-established structures and avoiding data duplication and fragmentation.


Assuntos
Homocistinúria , Transtornos Psicóticos , Betaína/efeitos adversos , Cistationina beta-Sintase , Homocisteína , Homocistinúria/tratamento farmacológico , Humanos , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Espasticidade Muscular
15.
Am J Otolaryngol ; 43(5): 103604, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35981434

RESUMO

OBJECTIVE: This case series describes a cohort of patients exposed to anhydrous ammonia vapors with clinical findings of laryngopharyngeal reflux (LPR). The study characterizes the identification of LPR as a consequence of vapor inhalation and the utility of PPI therapy in LPR secondary to inhalational ammonia exposure. METHODS: This is a case series of 15 patients exposed to anhydrous ammonia from a single chemical spill who experienced LPR several months after exposure. Symptoms of LPR were assessed at their initial consultation and by phone at least 30 days after treatment with low-dose PPI or diet modification. At this visit, patients underwent complete head and neck examination and flexible direct laryngoscopy. RESULTS: 15 patients were available for analysis before and after treatment. 93.3 % experienced at least three cardinal symptoms of LPR. 66 % of these patients had at least one LPR finding on flexible laryngoscopy. 73 % were treated with daily standard dose PPI, and 82 % of these patients experienced reduction of symptoms after 30 days of PPI treatment. Four of 15 patients were not taking the PPI as prescribed, and only one of these patients had resolution of LPR symptoms. CONCLUSION: We conclude that there is an association between anhydrous ammonia exposure and the development of LPR symptoms. In this study, treatment with PPIs was successful in reducing symptoms for most patients, and patients who did not receive PPIs experienced symptoms for a longer time.


Assuntos
Amônia , Refluxo Laringofaríngeo , Amônia/uso terapêutico , Estudos de Coortes , Humanos , Refluxo Laringofaríngeo/diagnóstico , Refluxo Laringofaríngeo/tratamento farmacológico , Laringoscopia , Inibidores da Bomba de Prótons/efeitos adversos
16.
Int J Mol Sci ; 23(21)2022 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-36361617

RESUMO

Demand for healthy diets has led researchers to explore new saccharide as sucrose alternatives. ᴅ-Psicose, the C-3 epimer of ᴅ-fructose, has a similar sweetness intensity to sucrose but contributes fewer calories. This study proposes a disaccharide with a stable structure derived from ᴅ-psicose. The compound with a spiro-tricyclic core was generated at 32% conversion via caramelization of ᴅ-psicose under acidic anhydrous conditions. The compound was identified by high-resolution mass spectrometry and multi-dimensional nuclear magnetic resonance (NMR). The molecular formula was established as C12H20O10 from the molecular weight of m/z 324.1055. Twelve signals were observed by the 13C NMR spectrum. This compound, denoted di-ᴅ-psicose anhydride (DPA), exhibited a lower water solubility (40 g/L) and higher thermal stability (peak temperature = 194.7 °C) than that of ᴅ-psicose (peak temperature = 126.5 °C). The quantitatively evaluated metal ion scavenging ability of DPA was the best in magnesium (average 98.6 ± 1.1%). This synthesis methodology can provide disaccharides with high stability-reducing heavy metals.


Assuntos
Anidridos , Frutose , Frutose/química , Sacarose , Glicoconjugados
17.
AAPS PharmSciTech ; 23(6): 198, 2022 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-35854200

RESUMO

The efficiency and safety of hormone delivery through the skin partly depend on the appropriate choice of vehicle and the type of formulation. The present study reports the skin cytotoxicity, irritancy, and safety of a newly developed anhydrous permeation-enhancing base (APEB) and the percutaneous absorption of progesterone, testosterone, estriol, and estradiol in APEB formulations. Using the human skin EpiDerm model, cell death was not observed after 4 h of exposure to APEB and was 48% after 24 h, indicating its mild to non-irritating property. APEB did not change the expression level of skin cell proliferation markers including PCNA, MCL-1, iNOS, and NFκB proteins, and apoptosis was minimal after 8-h exposure. The in vivo skin irritation and sensitization evaluation of APEB using a Human Repeat Insult Patch Test showed no adverse reaction of any kind during the course of the study. These results indicate the safety of APEB on skin tissues. The hormone percutaneous absorption was performed using human cadaver abdomen skin tissues and the Franz diffusion system, and hormone concentrations were determined by ELISA. Absorption was observed as early as 2 h of application and accumulated after 24 h to 2851 ± 66 ng/cm2, 2338 ± 594 ng/cm2, 55 ± 25 ng/cm2, and 341 ± 122 ng/cm2 for progesterone, testosterone, estriol, and estradiol, respectively. A steady flux rate of absorption of the hormones was observed within 24 h of application. These results suggest that APEB can be used as a vehicle to deliver these hormones through the skin and into the bloodstream for hormone replacement therapy.


Assuntos
Progesterona , Absorção Cutânea , Administração Cutânea , Estradiol , Estriol/metabolismo , Excipientes/metabolismo , Humanos , Preparações Farmacêuticas/metabolismo , Pele/metabolismo , Testosterona/metabolismo
18.
Angew Chem Int Ed Engl ; 61(35): e202208086, 2022 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-35801568

RESUMO

The development of effective, stable anhydrous proton-conductive materials is vital but challenging. Covalent organic frameworks (COFs) are promising platforms for ion and molecule conduction owing to their pre-designable structures and tailor-made functionalities. However, their poor chemical stability is due to weak interlayer interactions and intrinsic reversibility of linkages. Herein, we present a strategy for enhancing the interlayer interactions of two-dimensional COFs via importing planar, rigid triazine units into the center of C3 -symmetric monomers. The developed triazine-core-based COF (denoted as TPT-COF) possesses a well-defined crystalline structure, ordered nanochannels, and prominent porosity. The proton conductivity was ≈10 times those of non-triazinyl COFs, even reaching up to 1.27×10-2  S cm-1 at 160 °C. Furthermore, the TPT-COF exhibited structural ultrastability, making it an effective proton transport platform with remarkable conductivity and long-term durability.

19.
Int J Exp Pathol ; 102(2): 105-112, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33710702

RESUMO

The processes of hypertrophic scar formation are extremely complex, and current animal models have limitations in terms of the complete characterization of lesions. An ideal animal model is indispensable for exploring the complex progression of scar formation to elucidate its pathophysiology and to perform therapeutic testing. This study aimed to establish a long-term, consistent and easily testable animal model by injecting anhydrous alcohol into the dorsal trunk dermis of rabbits. The rabbits were injected with different amounts of anhydrous alcohol. Anhydrous alcohol was infiltrated into the subcutaneous and superficial fascia. The optimal amount of anhydrous alcohol was determined by measuring the area and thickness of the scar. The typical model was established by determining the optimum dosage, and then we analysed the histological characteristics and fibrosis-associated protein expression. The dermal scar was generated by treating with 2 ml/kg anhydrous alcohol and displayed histopathologic features that characterize human hypertrophic scarring, including a parallel collagen fibre orientation, dermal and epidermal thickening, broad collagen deposition and the loss of dermal adnexal structures. The expression of fibrotic pan-markers was also enhanced. Moreover, the scar features and duration were compared between the anhydrous alcohol model and the rabbit ear model. Our results show that injecting anhydrous alcohol in the rabbit model thickened the dermal tissue, stimulated dermal fibroproliferation and resulted in hypertrophic scars with protein and histologic features similar to those seen in humans. Taken together, the findings from this study show that our model could be a feasible and useful tool for further research on the pathogenesis of hypertrophic scars.


Assuntos
Álcoois/toxicidade , Cicatriz Hipertrófica/induzido quimicamente , Modelos Animais de Doenças , Animais , Cicatriz Hipertrófica/patologia , Masculino , Coelhos
20.
Chemistry ; 27(52): 13181-13189, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34096644

RESUMO

Access to lanthanide acetate coordination compounds is challenged by the tendency of lanthanides to coordinate water and the plethora of acetate coordination modes. A straightforward, reproducible synthetic procedure by treating lanthanide chloride hydrates with defined ratios of the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([C2 mim][OAc]) has been developed. This reaction pathway leads to two isostructural crystalline anhydrous coordination complexes, the polymeric [C2 mim]n [{Ln2 (OAc)7 }n ] and the dimeric [C2 mim]2 [Ln2 (OAc)8 ], based on the ion size and the ratio of IL used. A reaction with an IL : Ln-salt ratio of 5 : 1, where Ln=Nd, Sm, and Gd, led exclusively to the polymer, whilst for the heaviest lanthanides (Dy-Lu) the dimer was observed. Reaction with Eu and Tb resulted in a mixture of both polymeric and dimeric forms. When the amount of IL and/or the size of the cation was increased, the reaction led to only the dimeric compound for all the lanthanide series. Crystallographic analyses of the resulting salts revealed three different types of metal-acetate coordination modes where η2 µκ2 is the most represented in both structure types.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA